Sterically hindered 1h-1,2,3-triazol-5-ylidene abnormal n-heterocyclic carbene (ANHC) ligands, catalyst complexes thereof, and methods using same

Abstract

The present disclosure provides certain sterically hindered 1H-1,2,3-triazol-5-ylidene abnormal N-heterocyclic carbene (aNHC) ligands, catalyst complexes thereof, and methods 5 using same.

Description

[0001] TITLE OF THE INVENTION

[0002] Sterically Hindered I7 / - 1 ,2.3-triazol-5-ylidene Abnormal N-Heterocyclic Carbene (aNHC) Ligands, Catalyst Complexes Thereof, and Methods Using Same

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application no. 63 / 621,472, filed January 16, 2024. the entire contents of which are hereby incorporated by reference in their entireties.

[0005] STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0006] This invention was made with government support under grant number CHE- 1650766 awarded by the National Science Foundation and grant number R35GM133326 awarded by the National Institutes of Health. The government has certain rights in this invention.

[0007] BACKGROUND

[0008] Ligand design to control the catalytic properties of transition metals is one of the most powerful approaches in homogeneous catalysis. The catalytic efficiency engendered by a ligand principally hinges upon two factors: (1) the electronic properties of the ligand, and (2) the steric demand to stabilize the metal centers. In this context, in the last two decades, N- heterocyclic carbenes (NHCs) have been established as one of the most successful classes of ancillary ligands for transition-metal catalysis. The strong o-donor character of NHCs enables to form strong metal-ligand bonds with various transition-metals, which is ultimately responsible for high turnover numbers in catalysis. Furthermore, the strong o-donor character of the NHC ligands enables activation of unreactive bonds at metal centers. In parallel, another key consideration is the 'umbrella-shape’ steric bulk of N-heterocyclic carbenes, which brings the wingtips close to the metal centers. This unique spatial arrangement favors the kinetic stabilization of metals, prevents ligand dimerization and enables to form metal complexes with various metals at different oxidation states. In particular, steric tuning of the wingtips in the classical imidazol-2-ylidenes has been established as a powerful method to tune the selectivity and yield of catalytic processes.

[0009] In addition to classical N-heterocyclic carbenes, abnormal N-heterocyclic carbenes (aNHCs) have also been developed, which possess different electronic properties, including 1,2,3-triazolylidenes (e.g, U / -1.2.3-triazol-5-ylidene), imidazoline-4-ylidenes. and pyrazolinylidenes. While catalytic transformations using such aNHCs have been described in the literature, the reactivity and synthesis of such compounds are limited.

[0010] Thus, there is a need in the art for 17 / -l,2,3-triazol-5-ylidene ligands, metal complexes thereof, and methods of making and using the same. The present disclosure addresses this need.

[0011] BRIEF SUMMARY OF THE INVENTION

[0012] The invention provides, in one aspect, a compound of formula (I): wherein R1, R2, R3, and X1are defined elsewhere herein.

[0013] The invention provides, in one aspect, a compound of formula (II): wherein R1, R2, R3, M, L, m. n, and X2are defined elsewhere herein.

[0014] The invention provides, in one aspect, a method of promoting an intramolecular cyclization of a compound comprising a terminal alkyne and a carboxylic acid. In certain embodiments, the method comprises contacting the compound comprising the terminal alky ne and the carboxylic acid with at least one compound of formula (II), optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaBAr14), and optionally wherein M is Au or Cu.

[0015] The invention provides, in one aspect, a method of promoting a reaction between an alkyne and an aniline. In certain embodiments, the method comprises contacting the alkyne and the aniline with at least one compound of formula (II), optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

[0016] The invention provides, in one aspect, a method of promoting an intramolecular cyclization of a compound comprising a propargyl amide. In certain embodiments, the method comprises contacting the propargy l amide with at least one compound of formula (II), optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is AgOTf, and optionally wherein M is Au. The invention provides, in one aspect, a method of promoting a reaction between an alkyne and an arene. In certain embodiments, the method comprises contacting the alkyne and the arene with at least one compound of formula (II), optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

[0017] The invention provides, in one aspect, a method of promoting a reaction between an alkyne and an alkene. In certain embodiments, the method comprises contacting the alkyne and the alkene with at least one compound of formula (II), optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

[0018] The invention provides, in one aspect, a method of promoting hydration of an alkyne. In certain embodiments, the method comprises contacting the alkyne and an aniline with at least one compound of formula (II), optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Cu.

[0019] The invention provides, in one aspect, a method of promoting hydrosilylation of a ketone. In certain embodiments, the method comprises contacting the ketone and a trialkoxysilane, with at least one compound of formula (II) and a base, optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

[0020] The invention provides, in one aspect, a method of promoting borylation of an alkene. In certain embodiments, the method comprises contacting the alkene and a borylating agent with at least one compound of formula (II) and a base, optionally wherein the borylating agent is bis(pinacolato)diboron ( Bzpinz). optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

[0021] The invention provides, in one aspect, a method of promoting borylation of an alkyne. In certain embodiments, the method comprises contacting the alkyne and a borylating agent with at least one compound of formula (II) and a base, optionally wherein the borylating agent is bis(pinacolato)diboron (B2pin2), optionally wherein the base is an alkoxide base, and optionally wherein M is Cu or Ag.

[0022] The invention provides, in one aspect, a method of promoting a reduction of an alkyne. In certain embodiments, the method comprises contacting the alkyne and a reducing agent with at least one compound of formula (II) and a base, optionally w herein the base is an alkoxide base, optionally wherein the contacting further occurs in the presence of an alcohol, optionally wherein the reducing agent is a silane, optionally wherein the silane is polymethylhydrosiloxane (PHMS), and optionally wherein M is Cu.

[0023] The invention provides, in one aspect, a method of promoting oxidation of an aldehyde. In certain embodiments, the method comprises contacting the aldehyde and a base in the presence of O2 (g) with at least one compound of formula (II), optionally wherein the contacting occurs in the presence of an alcohol, optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

[0024] The invention provides, in one aspect, a method of promoting oxidation of an alcohol. In certain embodiments, the method comprises contacting the alcohol and a base in the presence of O2 (g) with at least one compound of formula (II), optionally wherein the base is a hydroxide base, and optionally wherein M is Cu.

[0025] The invention provides, in one aspect, a method of promoting a reaction between an aryl halide or heteroaryl halide and an amine. In certain embodiments, the method comprises comprising contacting the aryl halide or heteroaryl halide and the amine with at least one compound of formula (II) and a base, optionally w herein the halide is a chloride, optionally wherein the base is an alkoxide base, optionally wherein M is Pd.

[0026] The invention provides, in one aspect, a method of promoting an oxidation of an alkene. In certain embodiments, the method comprises contacting the alkene and an oxidizing agent with at least one compound of formula (II), optionally wherein the oxidizing agent is a peroxide, and optionally wherein M is Pd.

[0027] The invention provides, in one aspect, a method of promoting hydrogenation of an arene or heteroarene. In certain embodiments, the method comprises contacting the arene or heteroarene and H2 (g) with at least one compound of formula (II), optionally wherein M is Ir or Rh.

[0028] BRIEF DESCRIPTION OF THE FIGURES

[0029] The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments of the present application.

[0030] FIG. 1 A provides a schematic describing the reactivity of exemplary catalysts of the present disclosure. FIG. IB provides a schematic depicting a triazole "‘click” reaction. FIG. 1C depicts generic phosphine, carbene, and abnormal carbene ligands and their relative ligand donor strengths, as well as a resonance forms of a 1,2,3-triazolium-derived mesoionic carbene ligands. FIG. ID depicts certain exemplary N-heterocyclic carbene (NHC) ligands and a non-limiting, exemplary abnormal N-heterocyclic carbene (aNHC) ligand of the present disclosure. FIG. 2 depicts a non-limiting synthetic scheme for preparation of MIC-IPr* HI / HBF4 compounds. Conditions: (a) 6 (1.0 equiv), 'BuNCh (2.5 equiv), TMSN3 (1.8 equiv). (b) 6 (1.0 equiv), p-TSOH (4.5 equiv), NaNO2(3.0 equiv), KI (3.5 equiv), 0 °C to rt, 8 h. (c) 8 (1.0 equiv), TIPS-acetylene, 9 (3.0 equiv), Pd(PPhs)2C12 (5 mol%), Cui (7 mol%), Toluene: 'Pr2NH (3:1), 65 °C to rt, 12 h, then TBAF (2.0 equiv), THF, 15 min. (d) 10 (1.0 equiv), CuSCU FbO (25 mol%), Na-ascorbate (60 mol%). THF:MeCN:H2O (3:2:1), 80 °C. 4 days, (e) 11 (1.0 equiv), Mel, MeCN, 70 °C, 48 h or MesOBF4 (10 equiv), MeCN, rt, 48 h.

[0031] FIG. 3 depicts anon-limiting synthetic scheme for preparation of certain [MIC-IPr*- M] complexes. Conditions: (a) AuCl Me2S (1.0 equiv), KO'Bu (2.0 equiv), THF, 23 °C, 12 h, 91%. (b) AuCl Me2S (1.0 equiv), KO'Bu (2.0 equiv), THF, 23 °C, 12 h, 90%. (c) Se (3.0 equiv), KO'Bu (2.0 equiv). THF, 23 °C, 12 h, 93%. (d) [Ir(cod)Cl]2 (0.5 equiv), KO'Bu (2.0 equiv), THF, 23 °C, 16 h, then CO gas, 6 h, 66%. (e) KO'Bu (2.0 equiv), [Pd(cin)Cl]2 (0.5 equiv), THF, 23 °C, 15 h, 88%.

[0032] FIGs. 4A-4B depict x-ray structures of compounds 13 and 14. FIG. 4A: X-ray cry stal structure of complex 13. Two views: front (top); side (bottom). Hydrogen atoms and solvent molecules have been omitted for clarity. Selected bond lengths |Aj and angles [°J: Au-Cl.

[0033] I.997(4); Au-12, 2.5299(4); C1-C2, 1.386(6); C1-N3, 1.357(6); Cl-Au-I2, 173.94(12); C2- C1-N3, 103.6(4); C4-N3-C1, 126.6(4); C41-C2-C1, 130.6(4); N3-Cl-Au, 130.2(3). FIG. 4B: X-ray crystal structure of complex 14. Two views: front (top); side (bottom). Selected bond lengths [A] and angles [°]: Au-Cl, 1.984(3); Au-Cl, 2.2769(10); C1-C2. 1.358(5); Cl- N3, 1.381(5); Cl-Au-Cl, 177.81(10); C2-C1-N3, 103.2(3); C4-N3-C 1, 128.2(3); C37-C2- Cl, 126.9(3); N3-Cl-Au, 128.9(3).

[0034] FIG. 5 depicts an X-ray crystal structure of complex 17. Two views: front (top); side (bottom). Hydrogen atoms have been omitted for clarity. Selected bond lengths [A] and angles [°]: Pd-Cl, 2.048(5); Pd-I, 2.637(5); Pd-C70, 2.041(4); Pd-C71, 2.134(5); Pd-C72, 2.285(7); Cl-Nl, 1.376(6); C1-C2, 1.392(5); C37-N1, 1.460(5); C3-C2, 1.392(5); Cl-Pd- C70, 103.2(2); Cl-Pd-C71, 131.5(2); Cl-Pd-C71, 160.7(2); C70-Pd-C72, 59.8(3); Cl-Pd-

[0035] II, 98.95(12); N1-C1-C2, 102.0(4); C1-C2-C3, 131.8(4); C1-N1-C37, 129.4(4).

[0036] FIGs. 6A-6B depict Topographical stenc maps of [Au(MIC-IPr*)I] (13). [Pd(MIC- IPr*)(cin)I] (17), [Au(IPr*)I] and [Pd(IPr*)(cin)I] showing % Vw per quadrant.

[0037] FIGs. 7A-7E provides schemes demonstrating the catalytic reactivity of [Au(MIC- IPr*)Cl] in certain Au(I)-catalyzed functionalization reactions. FIG. 7A: Au(I)-catalyzed intramolecular cyclization of y-alkynoic acid. FIG. 7B: Au(I)-catalyzed hydroamination reaction. FIG. 7C: Au(I)-catalyzed cycloisomerization of A-(prop-2-yn-l-yl)benzamide. FIG. 7D: Au(I)-catalyzed synthesis of 2 / / -chromenes. FIG. 7E: Au(I)-catalyzed alkyne-alkene cycloaddition.

[0038] FIGs. 8A-8B depict certain DFT calculations performed at the B3LYP 6-31 l++g(d,p) level. 8A: HOMO and LUMO energy levels (eV) for certain exemplary NHC and / or aNHC ligands. FIG. 8B: HOMO (o-donating orbital) and LUMO (71-accepting) of MIC-IPr*.

[0039] FIG. 9 depicts certain exemplary, unsymmetrical aNHC ligands of the present disclosure.

[0040] FIG. 10 depicts a non-limiting synthetic scheme for preparation of unsymmetrical MIC-IPr* HI / HBF4 compounds. Conditions: (a) 6 (1.0 equiv), ThiNCh (2,5 equiv), TMSN3 (1.8 equiv). (b) 32a-32b (1.0 equiv). / ?-TSOH (4.5 equiv), NaNO2 (3.0 equiv), KI (3.5 equiv), 0 °C to rt, 4 h. (c) 33-34 (1.0 equiv). TMS-acetylene (1.5 equiv), Pd(PPh3)2C12 (2.5 mol%), Cui (5 mol%), heat, 12 h, then K2CO3 (2.0 equiv), MeOH, 2 h. (d) 6 (1.0 equiv), CuSO4 H2O (20 mol%), Na-ascorbate (60 mol%), THF / MeCN / H2O (3:2: 1), 80 °C, 4 days, (f) 37 (1.0 equiv), Mel, MeCN, 70 °C, 48 h or Me3OBF4 (10 equiv), MeCN, rt, 48 h.

[0041] FIG. 11 depicts a non-limiting synthetic scheme for preparation of certain [Au(MIC- IPr*)I] and [Au(MIC-IPr*)Cl] complexes. Conditions: AuCl Me2S (1.0 equiv), KO'Bu (2.0 equiv), THF, 23 °C.

[0042] FIGs. 12A-12C depict x-ray structures of compounds 40a-40c. FIG. 12A: X-ray crystal structure of complex 40a. Two views: front (top); side (bottom). Hydrogen atoms and solvent molecules have been omitted for clarity. Selected bond lengths [A] and angles [°]: Aul-C l , 2.015(3); Aul-CU, 2.015(3); C1-C2, 1 .382(4); C1-N3, 1.371(4); Cl-Aul-Cl ’, 180.0; C2-C1-N3, 102.6(3); C2-Cl-Aul, 136. 1(2); N3-Cl-Aul, 121.2(2). FIG. 12B: X-ray crystal structure of complex 40b. Two views: front (top); side (bottom). Selected bond lengths [A] and angles [°] : Aul-Il, 2.5361(3); Aul-Cl, 1.998(3); C1-C2, 1.386(5); Cl-Nl, 1.370(4); Cl-Aul-Il, 178.03(9); C2-C1-N1, 102.9(3); C2-Cl-Aul, 134.0(3); Nl-Cl-Aul, 122.9(2). FIG. 12C: X-ray crystal structure of complex 40c. Two views: front (top); side (bottom). Selected bond lengths [A] and angles [°]: Aul-Il, 2.5270(6); Aul-Cl, 1.988(7); C1-C2, 1.393(10); Cl-Nl, 1.372(9); Cl-Aul-Il, 172.4(2); C2-C1-N1, 102.3(6); C2-C1- Aul, 127.6(5); Nl-Cl-Aul. 130.1(5).

[0043] FIGs. 13A-13F depict topographical maps of 40a, 40b, 40c, [Au(MIC-Dipp / Ph)Cl], [Au(MIC-Mes / Mes)I] and [Au(MIC-Dipp / Dipp)Cl] showing % Nbw per quadrant.

[0044] FIG. 14 depicts a non-limiting synthetic scheme for preparation of certain [Se(MIC- IPr)*] complexes. Conditions: Se (3.0 equiv), KO'Bu (2.0 equiv). THF. 23 °C, 12 h.

[0045] FIG. 15 depicts a non-limiting synthetic scheme for preparation of certain [Ir(MIC- IPr*)(CCh)I] complexes. Conditions: (i) [Ir(cod)Cl]2 (0.5 equiv), KO'Bu (2.0 equiv), THF, 23 °C. 6 h. (ii) CO gas, 6 h.

[0046] FIGs. 16A-16C depict x-ray crystal structures for certain exemplary [Ir(MIC- IPr*)(CO2)I] complexes. FIG. 16A: X-ray crystal structure of complex 43a. Two views: front (top); side (bottom). Hydrogen atoms and solvent molecules have been omitted for clarity7. Selected bond lengths [A] and angles. FIG. 16B: X-ray crystal structure of complex 43b. Two views: front (top); side (bottom). Selected bond lengths [A] and angles [°]: Cl-Irl. 2.081(4); Irl-Il, 2.6408(4); IH-C47, 1.879(5); Irl-C46, 1.850(6); C l-Irl-Il, 90.22(11); C1-IH-C46, 91.81(18); C47-Irl-H, 86.36(15); C47-IH-C46, 91.5(2); Cl-Irl-C47, 176.08(19); C46-Irl-Il, 175.74(15), C2-C1-IH, 128.8(3); Nl-Cl-Irl, 129.7(3). FIG. 16C: X-ray7crystal structure of complex 43c. Two views: front (top); side (bottom). Selected bond lengths [A] and angles [°] : Cl-Irl, 2.082(4); Irl-Il, 2.6315(4); IH-C49, 1.890(5); IH-C50, 1.963(5); Cl-Irl-Il, 90.18(12); C1-IH-C50, 90.62(17); C49-Irl-H, 87.18(15); C49-IH- C50, 92.3(2); C1-IH-C49, 175.77(19); C50-IH-I1, 174.51(13), C2-C1-IH. 132.7(3); N3- Cl-Irl, 124.3(3).

[0047] FIG. 17 depicts the catalytic reactivity of [Au(MIC-IPr*)XJ complexes 40 and 41 in the Au(I)-catalyzed intramolecular cyclization of y-alky noic acid.

[0048] FIG. 18 depicts the catalytic reactivity7of [Au(MIC-IPr*)X] complexes 40 and 41 in the Au(I)-catalyzed hydroamination.

[0049] FIG. 19 depicts the catalytic reactivity of [Au(MIC-IPr*)Cl] complexes 41a-41b in the Au(I)-catalyzed alkyne cycloisomerization.

[0050] FIGs. 20A-20B depict certain DFT calculations performed at the B3LYP 6- 31 l++g(d,p) level for compounds 1 and 29-31. 20A: HOMO and LUMO energy levels (eV) for certain exemplary7NHC and / or aNHC ligands. FIG. 20B: HOMO (o-donating orbital) and LUMO (n-accepting) of MIC-IPr*.

[0051] FIGs. 21A-21F depict topographical steric maps of [Au(MIC-IPr* / Ph)Cl], [Au(MIC- IPr* / Mes)Cl], [Au(MIC-IPr* / Dipp)Cl], [Au(MIC-IPr* / IPr*)Cl], [Au(MIC-IMes)Cl], [Au(MIC-IPr)Cl], showing %Vta- per quadrant at the B3LYP 6-311++g(d.p) level.

[0052] DETAILED DESCRIPTION OF THE INVENTION

[0053] Reference will now be made in detail to certain embodiments of the disclosed subject matter, examples of which are illustrated in part in the accompanying drawings. While the disclosed subject matter will be described in conjunction with the enumerated claims, it will be understood that the exemplified subject matter is not intended to limit the claims to the disclosed subject matter.

[0054] Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of "‘about 0. 1% to about 5%” or “about 0. 1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g, 1%. 2%, 3%, and 4%) and the sub-ranges (e.g, 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. The statement “about X to Y” has the same meaning as “about X to about Y,” unless indicated otherwise. Likewise, the statement “about X, Y, or about Z” has the same meaning as “about X, about Y, or about Z,” unless indicated otherwise.

[0055] In this document, the terms “a,” “an,” or “the” are used to include one or more than one unless the context clearly dictates otherwise. The term “or” is used to refer to a nonexclusive “or” unless otherwise indicated. The statement “at least one of A and B” or “at least one of A or B” has the same meaning as “A, B, or A and B.” In addition, it is to be understood that the phraseology or terminology employed herein, and not otherwise defined, is for the purpose of description only and not of limitation. Any use of section headings is intended to aid reading of the document and is not to be interpreted as limiting; information that is relevant to a section heading may occur within or outside of that particular section. All publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference.

[0056] In the methods described herein, the acts can be carried out in any order, except when a temporal or operational sequence is explicitly recited. Furthermore, specified acts can be carried out concurrently unless explicit claim language recites that they can be carried out separately. For example, a claimed act of doing X and a claimed act of doing Y can be conducted simultaneously within a single operation, and the resulting process will fall within the literal scope of the claimed process.

[0057] Description

[0058] MIC -IP r * Ligands

[0059] In one aspect, the present disclosure describes the design and synthesis of most sterically -hindered IH- 1 ,2.3-triazol-5-ylidenes prepared to date, utilizing the triazole click reaction (Fig. 1A-C). l / 7-l,2,3-Triazol-5-ylidenes belong to a class of abnormal N- heterocyclic carbenes (aNHCs), where the canonical resonance structures of oNHCs are mesoionic (Fig. IB). These abnormal carbenes have attracted major attention as ancillary ligands in stabilizing reactive metal centers in inorganic chemistry, catalysis and materials science. Among nNHCs, 17 / -l,2,3-triazol-5-ylidenes have become the most attractive class of ligands due to their strong o-donating character, especially compared with the classical imidazol-2-ylidenes, and facile access via the modular Cu-catalyzed click assembly.

[0060] In the abnormal NHC ligands, the metal is bound to the C4 or C5 position of the heterocyclic ring rather than in the typical C2 position. This results in an overwhelmingly stronger o-donation as compared to the classical imidazol-2-ylidenes, a property that is critical for metal stabilization and transition-metal-catalysis using a variety of metals, catalytic reactions, and mechanisms. The major limitation of the known triazole ligands is the lack of steric hindrance around the metal center. This lack of steric hindrance leads to low kinetic stability' of metal-ligand complexes involving triazole ligands, thus preventing IH- l,2,3-triazol-5-ylidenes from realizing the full potential in transition-metal-catalysis despite strong o-donation as compared to the classical imidazol-2-ylidene NHC ligands.

[0061] The reactivity and effectiveness ofNHC-metal complexes hinge upon two key features, namely (1) very strong o-donor character of the NHC ligands that engenders the metal with nucleophilic characteristics and p-backbonding which leads to high stability of the metal-NHC bond, and, most importantly, (2) the variable steric bulk of the wingtip groups that protect the metal center and modulate its reactivity through the steric demand. Through utilizing the flexible steric bulk of the wingtips. NHC ligands typically favor the kinetic stabilization of the metal centers and the formation of low-coordinated metal complexes. The well-defined topology of the wingtips in N-heterocyclic carbenes has found extensive application in tuning the reactivity at the metal centres.

[0062] In this regard, sterically-demanding N-heterocyclic carbene ligands have attracted major attention in the last two decades. Namely IPr (IPr = 1 ,3-bis(2,6- diisopropylphenyl)imidazol-2-ylidene) (1), bearing isopropyl wingtips, which was subsequently established as the NHC ligand of choice for reaction development in homogenous catalysis and other applications. The present disclosure describes ligands and / or catalyst complexes thereof which represent a merger of sterically-hindered IPr* with strongly s-donating mesoionic scaffolds. Herein is reported the synthesis and full structural and electronic characterization of MIC-IPr*, a novel class of aNHC ligands that feature strong s- donation. wingtip flexibility and extremely bulky catalyst architectures. Notably, this ligand template is an overwhelmingly better o-donor than classical imidazol-2-ylidenes and the most sterically-hindered oNHC described to date. Unsymmetrical MIC-IPr * Ligands

[0063] To date, only less sterically-demanding N1 / C4 groups have been incorporated to stabilize the metal centers of 177-l,2,3-triazol-5-ylidene complexes. This lack of steric hindrance around the metal center is a major limitation of the known triazole ligands. The lack of steric hindrance leads to low kinetic stability of metal-ligand complexes involving triazole ligands, which in turn prevents this powerful class of NHCs from realizing the full promise in transition-metal-catalysis despite strong o-donation. Furthermore, despite the well -recognized advantages of ‘bulky -yet-flexible’ wingtips in the classical imidazol-2- ylidene ligand architectures, these wingtips are yet to be installed on the 177- 1 .2.3 -tri a / ol-5- ylidene ligands.

[0064] In general, 'bulky -yet-flexible’ ligands are NHC ligands where the steric hindrance of the wingtip provides stability to the metal through steric demand, while the wingtip flexibility enables the approach of the substrates to the catalytic pocket through steric adjustments. Examples of “flexible-steric-bulk” of NHC ligands are described in the literature, and their utility in organic transformations has similarly been described (Fig. 1C). In particular, the recent years have witnessed the emergence of IPr* (l,3-bis(2,6- bis(diphenylmethyl)-4- methylphenyl)imidazol-2-ylidene) as one of the most powerful ligands in catalysis. At present, IPr* along with IPr ( / .e., 1 ,3-bis(2,6- diisopropylphenyl)imidazol-2-ylidene) are the two most commonly used sterically-demanding NHC ligands in reaction screening and optimization.

[0065] In one aspect, the present disclosure describes the design and preparation of ligands comprising a bulky IPr* wingtip on the l / / - l .2.3-triazol-5-ylidene motif in an unsymmetrical arrangement to provide a gradually varying steric bulk for stabilizing and protecting the metal centers in transition-metal-catalysis. In the case of classical imidazol-2-ylidenes, installation of unsymmetrical steric bulk is not an easy task because of the synthetic approaches through unsymmetrical amidine or diamine needed for their assembly.

[0066] In certain embodiments, the modular ‘click triazole' chemistry through [3+2] cycloaddition can enable the synthesis of sterically demanding, unsymmetrical I H- 1.2.3- triazol-5-ylidenes, which (1) are not easily accessible in the classical imidazol-2-ylidene scaffold, and (2) are significantly stronger o-donors owing to the properties of the abnormal N-heterocyclic carbenes. The bulky symmetrical MIC-IPr* in the 177-l,2,3-triazol-5-ylidene template has been synthesized by optimizing crucial synthetic steps.

[0067] Described herein is a rational approach to an array of highly sterically -hindered. strongly o-donating and readily accessible ‘click triazole’ mesoionic I / / - 1 ,2.3-triazol-5- ylidenes utilizing an unsymmetrical IPr* wingtip. These ligands are highly electron-donating with gradually varying steric bulk in the I / / - I .2.3- triazol-5-ylidene template. Crucially, the unsymmetrical steric hindrance engenders high stability’ of the metal centers in 1 H- 1 ,2,3- triazol-5-ylidenes. Further, although mesoionic NHCs ty pically require silver to gold transmetalation step for the synthesis of gold(I) complexes, bulky unsymmetrical MIC-IPr* ligands directly afford Au(I)-MIC complexes, thus obviating the need for silver intermediates. Additionally, the sterically-demanding MIC-IPr* ligands afford synthetically valuable iridium(I)-carbonyl complexes, [Ir(MIC)(C0)2l], in high yield, which was previously difficult to achieve due to low-yielding synthetic steps.

[0068] Full characterization of unsymmetrical MIC- IPr* complexes through crystallographic studies,77Se NMR and TEP values is described. DFT studies indicate that these unsymmetrical I H- 1 .2.3-triazol-5-ylidenes are significantly stronger o-donors than the classical imidazol-2-ylidenes, such as IPr* or IPr.

[0069] The hypothesis of increasing steric bulk to increase the catalytic activity’ was validated by the experiments described herein. Considering that these unsymmetrical l / / -l,2,3-triazol- 5-ylidenes are significantly stronger o-donors than the classical imidazol-2- ylidenes, while providing a set of readily-accessible, gradually vary ing sterics around the metal center, the bulky 177-l,2,3-triazol-5-ylidenes of the present disclosure are of significant utility in stabilization of metal centers and transition-metal-catalysis.

[0070] Definitions

[0071] The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range.

[0072] The term “acyl” as used herein refers to a group containing a carbonyl moiety' wherein the group is bonded via the carbonyl carbon atom. The carbonyl carbon atom is bonded to a hydrogen forming a “formyl” group or is bonded to another carbon atom, which can be part of an alkyl, aryl, aralkyl cycloalkyl, cycloalkylalkyl, heterocyclyl, heterocyclylalkyl. heterocycloalkyl, heteroaryl, heteroarylalkyl group or the like. An acyl group can include 0 to about 12, 0 to about 20, or 0 to about 40 additional carbon atoms bonded to the carbonyl group. An acyl group can include double or triple bonds within the meaning herein. An acryloyl group is an example of an acyl group. An acyl group can also include heteroatoms within the meaning herein. A nicotinoyl group (pyridyl-3-carbonyl) is an example of an acyl group within the meaning herein. Other examples include acetyl, benzoyl, phenylacetyl, pyridylacetyl, cinnamoyl, and acryloyl groups and the like. When the group containing the carbon atom that is bonded to the carbonyl carbon atom contains a halogen, the group is termed a “haloacyl” group. An example is a trifluoroacetyl group.

[0073] The term “alkenyl’' as used herein refers to straight and branched chain and cyclic alkyl groups as defined herein, except that at least one double bond exists between two carbon atoms. Thus, alkenyl groups have from 2 to 40 carbon atoms, or 2 to about 20 carbon atoms, or 2 to 12 carbon atoms or, in some embodiments, from 2 to 8 carbon atoms. Examples include, but are not limited to vinyl, -CH=C=CCH2, -CH=CH(CH3), - CH=C(CH3)2, -C(CH3)=CH2, -C(CH3)=CH(CH3), -C(CH2CH3)=CH2, cyclohexenyl, cyclopentenyl, cyclohexadienyl, butadienyl. pentadienyl, and hexadienyl among others.

[0074] The term “alkoxy” as used herein refers to an oxygen atom connected to an alkyl group, including a cycloalkyl group, as defined herein. Examples of linear alkoxy groups include but are not limited to methoxy , ethoxy , propoxy , butoxy, pentyloxy, hexyloxy, and the like. Examples of branched alkoxy include but are not limited to isopropoxy, sec-butoxy, tert-butoxy, isopentyloxy, isohexyloxy, and the like. Examples of cyclic alkoxy include but are not limited to cyclopropyloxy, cyclobutyloxy, cyclopentyloxy, cyclohexyloxy, and the like. An alkoxy group can include about 1 to about 12, about 1 to about 20, or about 1 to about 40 carbon atoms bonded to the oxygen atom, and can further include double or triple bonds, and can also include heteroatoms. For example, an allyloxy group or a methoxyethoxy group is also an alkoxy group within the meaning herein, as is a methylenedi oxy group in a context where two adjacent atoms of a structure are substituted therewith.

[0075] The term “alkynyl” as used herein refers to straight and branched chain alkyl groups, except that at least one triple bond exists between two carbon atoms. Thus, alkynyl groups have from 2 to 40 carbon atoms, 2 to about 20 carbon atoms, or from 2 to 12 carbons or, in some embodiments, from 2 to 8 carbon atoms. Examples include, but are not limited to - C=CH. -C =C(CH3). -C =C(CH2CH3). -CH2C=CH. -CH2C =C(CH3). and -CH2C=C(CH2CH3) among others.

[0076] The term “alkyl” as used herein refers to straight chain and branched alky l groups and cycloalkyl groups having from 1 to 40 carbon atoms, 1 to about 20 carbon atoms, 1 to 12 carbons or. in some embodiments, from 1 to 8 carbon atoms. Examples of straight chain alkyl groups include those with from 1 to 8 carbon atoms such as methyl, ethyl, n-propyl, n- buty l, n-pentyl. n-hexyl, n-heptyl, and n-octyl groups. Examples of branched alkyl groups include, but are not limited to, isopropyl, iso-butyl, sec-butyl, t-butyl. neopentyl, isopentyl, and 2,2-dimethylpropyl groups. As used herein, the term '‘alkyl” encompasses n-alkyl, isoalkyl, and anteisoalkyl groups as well as other branched chain forms of alkyd.

[0077] Representative substituted alky 1 groups can be substituted one or more times with any of the groups listed herein, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups.

[0078] The term “amine” as used herein refers to primary, secondary, and tertiary amines having, e.g ., the formula N(group)3 wherein each group can independently be H or non-H, such as alky 1, ary 1, and the like. Amines include but are not limited to R-NH2, for example, alkylamines, arylamines, alkylarylamines; R2NH wherein each R is independently selected, such as dialkylamines, diarylamines, aralkylamines, heterocyclylamines and the like; and R3N wherein each R is independently selected, such as trialkylamines, dialkylarylamines, alkyldiarylamines, triary lamines, and the like. The term “amine” also includes ammonium ions as used herein.

[0079] The term “ammo group” as used herein refers to a substituent of the form -NH2, - NHR, -NR2, -NR3+, wherein each R is independently selected, and protonated forms of each, except for -NR? . which cannot be protonated. Accordingly, any compound substituted with an amino group can be viewed as an amine. An “amino group” within the meaning herein can be a primary, secondary, tertiary, or quaternary amino group. An “alkylamino” group includes a monoalkylamino, dialkylamino, and trialkylamino group.

[0080] The term “aniline” as used herein refers to an amine having at least one ary l or heteroaryl substituent.

[0081] The term “aralkyl” as used herein refers to alkyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to an aryl group as defined herein. Representative aralkyl groups include benzyl and phenylethyl groups and fused (cycloalkylaryl)alkyl groups such as 4-ethyl-indanyl. Aralkenyl groups are alkenyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to an aryl group as defined herein.

[0082] The term “aroyl” as used herein refers to an aryl group, as defined elsewhere herein, substituted at any one position with a carbonyl moiety7( / .<?., C(=O)). Use of the term “aroyl” in combination with another term (e.g. , chloride), indicates that the carbonyl linked to the ary l group is substituted with the substituent defined by the term used in the combination. For example, PhC(=O)Cl (z.e., benzoyl chloride) is an aroyl chloride. The term "aryl" as used herein refers to cyclic aromatic hydrocarbon groups that do not contain heteroatoms in the ring. Thus aryl groups include, but are not limited to, phenyl, azulenyl, heptalenyl, biphenyl, indacenyl, fluorenyl, phenanthrenyl, triphenylenyl, pyrenyl, naphthacenyl, chrysenyl, biphenylenyl, anthracenyl, and naphthyl groups. In some embodiments, aryl groups contain about 6 to about 14 carbons in the ring portions of the groups. Aryl groups can be unsubstituted or substituted, as defined herein. Representative substituted aryl groups can be mono-substituted or substituted more than once, such as, but not limited to, a phenyl group substituted at any one or more of 2-, 3-, 4-, 5-, or 6-positions of the phenyl ring, or a naphthyl group substituted at any one or more of 2- to 8-positions thereof. Use of the term "aryl" in combination with another term (e.g. , iodide, chloride, boronic acid, and magnesium halide, inter alia), indicates that the aryl group is substituted at one or more positions with the substituent defined by the term used in the combination. For example, an aryl chloride indicates that the aryl is substituted with at least one chloride.

[0083] The term “atm” as used herein refers to a pressure in atmospheres under standard conditions. Thus, 1 atm is a pressure of 101 kPa, 2 atm is a pressure of 202 kPa, and so on.

[0084] The term “counter anion” as used herein refers to a negatively charged ion that accompanies a cationic species (i.e. positively charged ion) in order to maintain electric neutrality7. For example, the chloride ion (CF) is the counter anion to sodium (Na+) in NaCl. Non-limiting examples of counter anions include F', Cl’, Br’, I’, H’, Ns’. PhCH=CHCH2‘, PhCH’CH=CH2, F3CS(=O)2O’ (OTf), (F3CS(=O)2)2N’ (NTf2). F3CC(=O)O’ (TFA). BFf, and PF6’.

[0085] The term “cycloalkyd” as used herein refers to cyclic alkyl groups such as, but not limited to, cyclopropyl, cyclobutyl, cyclopentyd. cyclohexyl, cyclohepty l, and cyclooctyl groups. In some embodiments, the cycloalkyl group can have 3 to about 8-12 ring members, whereas in other embodiments the number of ring carbon atoms range from 3 to 4, 5, 6, or 7. Cycloalkyl groups further include polycyclic cycloalkyl groups such as, but not limited to, norbomyl, adamanty 1, bomyl, campheny 1, isocamphenyl, and carenyl groups, and fused rings such as, but not limited to, decalinyl, and the like. Cycloalkyl groups also include rings that are substituted with straight or branched chain alkyl groups as defined herein. Representative substituted cycloalky 1 groups can be mono-substituted or substituted more than once, such as, but not limited to, 2,2-, 2,3-, 2,4- 2,5- or 2,6-disubstituted cyclohexyl groups or mono-, di- or tri-substituted norbomy l or cycloheptyl groups, which can be substituted with, for example, amino, hydroxy, cyano, carboxy, nitro, thio, alkoxy, and halogen groups. The term “cycloalkenyl” alone or in combination denotes a cyclic alkenyl group. The term “electrophile'’ as used herein refers to a chemical species that forms a bond with a nucleophile by accepting an electron pair in a chemical reaction (e.g. SNI. SN2, and carbonyl [1,2] -addition). Non-limiting examples of electrophiles include alkyl halides (e.g. Mel), benzyl halides (e.g. BnBr), dihalides (e.g. Bn), aldehydes (e.g. Ph-CHO), acyl halides (e.g. Ph(C=O)Cl), N-electrophiles (e.g. RC(=0)0NR2), and O-electrophiles (e.g. RC(=O)O2R).

[0086] The terms “epoxy-functional” or “epoxy-substituted” as used herein refers to a functional group in which an oxygen atom, the epoxy substituent, is directly attached to two adjacent carbon atoms of a carbon chain or ring system. Examples of epoxy-substituted functional groups include, but are not limited to, 2,3-epoxypropyl, 3,4-epoxybutyl, 4,5- epoxypentyl. 2,3-epoxypropoxy. epoxypropoxypropyl, 2-glycidoxyethyl. 3-glycidoxypropyl, 4-glycidoxybutyl, 2-(gly ci doxy carbonyl jpropyl, 3-(3,4-epoxycylohexyl)propyl, 2-(3,4- epoxycyclohexyljethyl, 2-(2,3-epoxycylopentyl)ethyl, 2-(4-methyl-3,4- epoxycyclohexyl)propyl, 2-(3,4-epoxy-3-methylcylohexyl)-2-methylethyl, and 5,6- epoxyhexyl.

[0087] The terms “halo.” “halogen,” or “halide” group, as used herein, by themselves or as part of another substituent, mean, unless otherwise stated, a fluorine, chlorine, bromine, or iodine atom.

[0088] The term “haloalkyl” group, as used herein, includes mono-halo alkyl groups, poly- halo alkyl groups wherein all halo atoms can be the same or different, and per-halo alkyl groups, wherein all hydrogen atoms are replaced by halogen atoms, such as fluoro. Examples of haloalkyl include trifluoromethyl, 1,1 -di chloroethyl, 1,2-dichloroethyl, l,3-dibromo-3,3- difluoropropyl, peril uorobutyl. and the like.

[0089] The term “heteroaralkynyl” as used herein refers to alkynyl groups as defined herein in which a hydrogen or carbon bond of an alkynyl group is replaced with a bond to a heteroaryl group as defined herein. Representative aralkynyl groups include, but are not limited to, 2-ethynylpyridine and 2-ethynylthiophene.

[0090] The term “heteroaryl” as used herein refers to aromatic ring compounds containing 5 or more ring members, of which, one or more is a heteroatom such as, but not limited to. N, O, and S; for instance, heteroaryl rings can have 5 to about 8-12 ring members. A heteroaryl group is a variety of a heterocyclyl group that possesses an aromatic electronic structure. A heteroaryl group designated as a Cv-heteroaryl can be a 5-ring with two carbon atoms and three heteroatoms, a 6-ring with two carbon atoms and four heteroatoms and so forth. Likewise a C4-heteroaryl can be a 5-ring with one heteroatom, a 6-ring with two heteroatoms, and so forth. The number of carbon atoms plus the number of heteroatoms sums up to equal the total number of ring atoms. Heteroaryl groups include, but are not limited to, groups such as pyrrolyl, pyrazolyl, triazolyl, tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridinyl, thiophenyl, benzothiophenyl, benzofuranyl, indolyl, azaindolyl, indazolyl, benzimidazolyl, azabenzimidazolyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, imidazopyridinyl, isoxazolopyridinyl, thianaphthalenyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl, quinoxalinyl. and quinazolinyl groups. Heteroaryl groups can be unsubstituted, or can be substituted with groups as is discussed herein. Representative substituted heteroary l groups can be substituted one or more times with groups such as those listed herein.

[0091] Additional examples of aryl and heteroaryl groups include but are not limited to phenyl, biphenyl, indenyl, naphthyl (1 -naphthyl, 2-naphthyl), N-hydroxytetrazolyl, N- hydroxytriazolyl, N-hydroxyimidazolyl, anthracenyl (1-anthracenyl, 2-anthracenyl, 3- anthracenyl), thiophenyl (2 -thieny l, 3-thienyl), furyl (2 -furyl, 3-furyl) , indolyl, oxadiazolyl, isoxazolyl, quinazolinyl. fluorenyl, xanthenyl. isoindanyl. benzhydryl, acridinyl, thiazolyl, pyrrolyl (2-pyrrolyl). pyrazolyl (3-pyrazolyl). imidazolyl (1-imidazolyl, 2-imidazolyl, 4-imidazolyl, 5-imidazolyl), triazolyl (1,2,3-triazol-l-yl, l,2,3-triazol-2-yl l,2,3-triazol-4-yl, l,2,4-triazol-3-yl), oxazolyl (2-oxazolyl, 4-oxazolyl, 5-oxazolyl), thiazolyl (2-thiazolyl, 4- thiazolyl. 5-thiazolyl), pyridyl (2-pyridyl, 3-pyridyl, 4-pyridyl), pyrimidinyl (2-pyrimidinyl, 4-pyrimidinyl, 5 -pyrimidinyl, 6-pyrimidinyl), pyrazinyl, pyridazinyl (3- pyridazinyl. 4- pyridazinyl, 5-pyridazinyl), quinolyl (2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6- quinolyl, 7-quinolyl, 8-quinolyl), isoquinolyl (1 -isoquinolyl, 3-isoquinolyl, 4-isoquinolyl, 5- isoquinolyl, 6-isoquinolyl, 7-isoquinolyl, 8-isoquinolyl), benzo[b]furanyl (2-benzo[b]furanyl, 3-benzo[b]furanyl. 4-benzo[b] furanyl. 5-benzo[b]furanyl. 6-benzo[b] furanyl. 7- benzofb] furanyl), 2,3-dihydro-benzo[b]furanyl (2-(2,3-dihydro-benzo[b]furanyl), 3-(2,3- dihydro-benzo[b] furanyl), 4-(2,3-dihydro-benzo[b]furanyl), 5-(2,3-dihydro-benzo[b]furanyl), 6-(2,3-dihydro-benzo[b]furanyl), 7-(2,3-dihydro-benzo[b]furanyl), benzo[b]thiophenyl (2- benzo[b]thiophenyl, 3-benzo[b]thiophenyl, 4-benzo[b]thiophenyl, 5-benzo[b]thiophenyl, 6- benzo[b]thiophenyl, 7-benzo[b]thiophenyl). 2,3-dihydro-benzo[b]thiophenyl, (2-(2,3- dihydro-benzo[b]thiophenyl), 3-(2,3-dihydro-benzo[b]thiophenyl), 4-(2,3-dihydro- benzo[b]thiophenyl), 5-(2,3-dihydro-benzo[b]thiophenyl), 6-(2,3-dihydro- benzo[b]thiophenyl). 7-(2,3-dihydro-benzo[b]thiophenyl), indolyl (1-indolyl, 2-indolyl,

[0092] 3-indolyl, 4-indolyl, 5-indolyl. 6-indolyl, 7-indolyl), indazole (1-indazolyl. 3-indazolyl,

[0093] 4-indazolyl, 5-indazolyl, 6-indazolyl, 7-indazolyl), benzimidazolyl (1-benzimidazolyl, 2-benzimidazolyl, 4-benzimidazolyl, 5 -benzimidazolyl, 6-benzimidazolyl, 7-benzimidazolyl, 8-benzimidazolyl). benzoxazolyl (1-benzoxazolyl, 2-benzoxazolyl), benzothiazolyl (1- benzothiazolyl, 2-benzothiazolyl, 4-benzothiazolyl, 5-benzothiazolyL 6-benzothiazolyl, 7-benzothiazolyl), carbazolyl (1-carbazolyl, 2-carbazolyl, 3-carbazolyl, 4-carbazolyl), 5H-dibenz[b,f|azepine (5H-dibenz[b,f] azepin- 1-yl, 5H-dibenz[b,f]azepine-2-yl, 5H-dibenz[b.f|azepine-3-yl, 5H-dibenz[b,f|azepine-4-yl, 5H-dibenz[b,f]azepine-5-yl),

[0094] 10.1 l-dihydro-5H-dibenz[b.f] azepine (10.11-dihydro-5H-dibenz[b.f] azepine- 1-yl,

[0095] 10.1 l-dihydro-5H-dibenz[b,f|azepine-2-yl, 10,l l-dihydro-5H-dibenz[b,f|azepine-3-yl,

[0096] 10,1 l-dihydro-5H-dibenz[b,f|azepine-4-yl, 10,1 l-dihydro-5H-dibenz[b,f|azepine-5-yl), and the like.

[0097] The term “heterocyclylalkyl” as used herein refers to alkyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group as defined herein is replaced with a bond to a heterocyclyl group as defined herein. Representative heterocyclyl alkyl groups include, but are not limited to, furan-2-yl methyl, furan-3-yl methyl, pyridine-3-yl methyl, tetrahydrofuran-2-yl ethyl, and indol-2-yl propyl.

[0098] The term “heteroarylalkyl” as used herein refers to alkyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group is replaced with a bond to a heteroaryl group as defined herein.

[0099] The term “heterocyclylalkyf’ as used herein refers to alkyl groups as defined herein in which a hydrogen or carbon bond of an alkyl group as defined herein is replaced with a bond to a heterocyclyl group as defined herein. Representative heterocyclyl alkyl groups include, but are not limited to, furan-2-yl methyl, furan-3-yl methyl, pyridine-3-yl methyl, tetrahydrofuran-2-yl ethyl, and indol-2-yl propyl.

[0100] The term “heterocyclyl” as used herein refers to aromatic and non-aromatic ring compounds containing three or more ring members, of which one or more is a heteroatom such as, but not limited to, N, O, and S. Thus, a heterocyclyl can be a cycloheleroalkyl. or a heteroaryl, or if polycyclic, any combination thereof. In some embodiments, heterocyclyl groups include 3 to about 20 ring members, whereas other such groups have 3 to about 15 ring members. A heterocyclyl group designated as a C2-heterocyclyl can be a 5-ring with two carbon atoms and three heteroatoms, a 6-ring with two carbon atoms and four heteroatoms and so forth. Likewise a C4-heterocyclyl can be a 5-ring with one heteroatom, a 6-ring with two heteroatoms, and so forth. The number of carbon atoms plus the number of heteroatoms equals the total number of ring atoms. A heterocyclyl ring can also include one or more double bonds. A heteroaryl ring is an embodiment of a heterocyclyl group. The phrase “heterocyclyl group” includes fused ring species including those that include fused aromatic and non-aromatic groups. For example, a dioxolanyl ring and a benzdioxolanyl ring system (methylenedioxyphenyl ring system) are both heterocyclyl groups within the meaning herein. The phrase also includes polycyclic ring systems containing a heteroatom such as, but not limited to, quinuclidyl. Heterocyclyl groups can be unsubstituted, or can be substituted as discussed herein. Heterocyclyl groups include, but are not limited to. pyrrolidinyl, piperidinyl, piperazinyl, morphohnyl, pyrrolyl, pyrazolyl. triazolyl. tetrazolyl, oxazolyl, isoxazolyl, thiazolyl, pyridinyl, thiophenyl, benzothiophenyl, benzofuranyl, dihydrobenzofuranyl, indolyl, dihydroindolyl, azaindolyl, indazolyl, benzimidazolyl, azabenzimidazolyl, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, imidazopyridinyl, isoxazolopyridinyl, thianaphthalenyl, purinyl, xanthinyl, adeninyl, guaninyl, quinolinyl, isoquinolinyl, tetrahydroquinolinyl, quinoxalinyl, and quinazolinyl groups. Representative substituted heterocyclyl groups can be mono-substituted or substituted more than once, such as, but not limited to, piperidinyl or quinolinyl groups, which are 2-, 3-, 4-, 5-, or 6- substituted, or disubstituted with groups such as those listed herein.

[0101] The term “hydrocarbon” or “hydrocarbyl” as used herein refers to a molecule or functional group that includes carbon and hydrogen atoms. The term can also refer to a molecule or functional group that normally includes both carbon and hydrogen atoms but wherein all the hydrogen atoms are substituted with other functional groups. Hydrocarbyl groups can be shown as (Ca-Cb)hydrocarbyl, wherein a and b are integers and mean having any of a to b number of carbon atoms. For example, (C1-C4)hydrocarbyl means the hydrocarbyl group can be methyl (Ci), ethyl (C2), propyl (C3), or butyl (C4), and (Co- Cb)hydrocarbyl means in certain embodiments there is no hydrocarbyl group.

[0102] The term “IMes” as used herein refers to l,3-bis(2,4,6-trimethylphenyl)-l,3-dihydro- 2H-imidazol-2-ylidene.

[0103] The term “IrnPy” as used herein refers to imidazo[l,5- a]pyridine.

[0104] The term “IPr” as used herein refers to l,3-bis(2,6-diisopropylphenyl)-l,3-dihydro- 2H-imidazol-2-ylidene.

[0105] The term “IPr*” as used herein refers to 1.3-bis((2,6-(dibenzhydryl))-4- methylphenyl)-l,3-dihydro-2H-imidazol-2-ylidene.

[0106] The term “independently selected from” as used herein refers to referenced groups being the same, different, or a mixture thereof, unless the context clearly indicates otherwise. Thus, under this definition, the phrase “X1, X2, and X3are independently selected from noble gases” would include the scenario where, for example, X1, X2, and X3are all the same, where X1, X2, and X3are all different, where X1and X2are the same but X3is different, and other analogous permutations.

[0107] The term '‘Lewis acid” as used herein refers to a chemical species that possesses an empty orbital which is capable of accepting a pair of non-bonding electrons from a species having a filled orbital containing an electron pair (z.e., a Lewis base).

[0108] The term “monovalent” as used herein refers to a substituent connecting via a single bond to a substituted molecule. When a substituent is monovalent, such as, for example. F or Cl, it is bonded to the atom it is substituting by a single bond.

[0109] The term “neutral ligand” or “ligand” as used herein, refers to a ligand having no net charge prior to association with, or after dissociation from, a metal center. Non-limiting examples of neutral ligands include alkene (e.g., cyclooctadiene). CO, amine (e.g.. NMes). phosphine (e.g., PPhs), and pyridyl ligands, wherein coordination occurs via the nitrogen lone pair of the pyridyl group.

[0110] The term “nitrile” as used herein refers to an organic compound comprising a cyano group (C=N).

[0111] The term “organic group” as used herein refers to any carbon-containing functional group. Examples can include an oxygen-containing group such as an alkoxy group, aryloxy group, aralkyloxy group, oxo(carbonyl) group; a carboxyl group including a carboxylic acid, carboxylate, and a carboxylate ester; a sulfur-containing group such as an alkyl and aryl sulfide group; and other heteroatom-containing groups. Non-limiting examples of organic groups include OR, OOR, OC(O)N(R)2, CN, CF3, OCF3, R, C(O), methylenedioxy, ethylenedioxy, N(R)2, SR, SOR, SO2R, SO2N(R)2, SO3R, C(O)R, C(O)C(O)R, C(O)CH2C(O)R, C(S)R, C(O)OR, OC(O)R, C(0)N(R)2, OC(O)N(R)2, C(S)N(R)2, (CH2)O- 2N(R)C(0)R, (CH2)o-2N(R)N(R)2, N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)C0N(R)2, N(R)SO2R, N(R)SO2N(R)2, N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(0)N(R)2, N(R)C(S)N(R)2, N(COR)COR, N(OR)R, C(=NH)N(R)2, C(O)N(OR)R, C(=NOR)R, and substituted or unsubstituted (C1-Cioo)hydrocarbyl, wherein R can be hydrogen (in examples that include other carbon atoms) or a carbon-based moiety, and wherein the carbon-based moiety can be substituted or unsubstituted.

[0112] The term “protic solvent” as used herein refers to a solvent that has a hydrogen atom bound to a heteroatom such as O, N, or S, such that the H+is labile. Non-limiting examples of protic solvents include methanol, ethanol, isopropanol, acetic acid, water, n-butanol, and formic acid. Conversely, an “aprotic solvent” as used herein refers to a solvent lacking dissociable hydrogen ions (i.e. non-acidic) to an appreciable extent. Non-limiting examples of aprotic solvents include ethyl acetate (EtOAc), diethyl ether (Et2O), tetrahydrofuran (THF), dimethylformamide (DMF), and 1 ,4-di oxane.

[0113] The term '‘room temperature’’ refers to a temperature of about 15 °C to 28 °C.

[0114] The term “solvent” as used herein refers to a liquid that can dissolve a solid, liquid, or gas. Non-limiting examples of solvents are silicones, organic compounds, water, alcohols, ionic liquids, and supercritical fluids.

[0115] The term “substantially” as used herein refers to a majority of, or mostly, as in at least about 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98%, 99%, 99.5%, 99.9%, 99.99%, or at least about 99.999% or more, or 100%. The term “substantially free of’ as used herein can mean having none or having a trivial amount of, such that the amount of material present does not affect the material properties of the composition including the material, such that the composition is about 0 wt% to about 5 wt% of the material, or about 0 wt% to about 1 wt%, or about 5 wt% or less, or less than, equal to, or greater than about 4.5 wt%, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt% or less. The term “substantially free of’ can mean having a trivial amount of, such that a composition is about 0 wt% to about 5 wt% of the material, or about 0 wt% to about 1 wt%. or about 5 wt% or less, or less than, equal to, or greater than about 4.5 wt%, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, 0.01, or about 0.001 wt% or less, or about 0 wt%.

[0116] The term “substituted” as used herein in conjunction with a molecule or an organic group as defined herein refers to the state in which one or more hydrogen atoms contained therein are replaced by one or more non-hydrogen atoms. The term “functional group” or “substituent” as used herein refers to a group that can be or is substituted onto a molecule or onto an organic group. Examples of substituents or functional groups include, but are not limited to, a halogen (e.g., F, Cl. Br. and I); an oxygen atom in groups such as hydroxy groups, alkoxy groups, aryloxy groups, aralkyloxy groups, oxo(carbonyl) groups, carboxyl groups including carboxylic acids, carboxylates, and carboxylate esters; a sulfur atom in groups such as thiol groups, alkyl and aryl sulfide groups, sulfoxide groups, sulfone groups, sulfonyl groups, and sulfonamide groups; a nitrogen atom in groups such as amines, hydroxyamines, nitriles, nitro groups, N-oxides. hydrazides, azides, and enamines; and other heteroatoms in various other groups. Non-limiting examples of substituents that can be bonded to a substituted carbon (or other) atom include F, Cl, Br, I, OR, OC(O)N(R)2, CN, NO, NO2, ONO2, azido, CF3, OCF3, R, O (oxo), S (thiono), C(O), S(O), methylenedioxy, ethylenedioxy. N(R)2, SR, SOR. SO2R, SO2N(R)2, SO3R. C(O)R. C(O)C(O)R. C(O)CH2C(O)R, C(S)R, C(O)OR, OC(O)R, C(O)N(R)2, OC(O)N(R)2, C(S)N(R)2, (CH2)O- 2N(R)C(0)R, (CH2)O-2N(R)N(R)2, N(R)N(R)C(O)R, N(R)N(R)C(O)OR, N(R)N(R)C0N(R)2, N(R)SO2R. N(R)SO2N(R)2, N(R)C(O)OR, N(R)C(O)R, N(R)C(S)R, N(R)C(0)N(R)2, N(R)C(S)N(R)2, N(COR)COR, N(OR)R, C(=NH)N(R)2, C(O)N(OR)R, and C(=NOR)R, wherein R can be hydrogen or a carbon-based moiety; for example, R can be hydrogen, (C1- Cioo) hydrocarbyl, alkyl, acyl, cycloalkyl, aryl, aralkyl, heterocyclyl, heteroaryl, or heteroarylalkyl; or wherein two R groups bonded to a nitrogen atom or to adjacent nitrogen atoms can together with the nitrogen atom or atoms form a heterocyclyl.

[0117] Preparation of Compounds

[0118] The compounds described herein can possess one or more stereocenters, and each stereocenter can exist independently in either the (R) or OS') configuration. In certain embodiments, compounds described herein are present in optically active or racemic forms. It is to be understood that the compounds described herein encompass racemic, optically- active, regioisomeric and stereoisomeric forms, or combinations thereof that possess the therapeutically useful properties described herein. Preparation of optically active forms is achieved in any suitable manner, including by way of non-limiting example, by resolution of the racemic form with recrystallization techniques, synthesis from optically-active starting materials, chiral synthesis, or chromatographic separation using a chiral stationary phase. In certain embodiments, a mixture of one or more isomer is utilized as the therapeutic compound described herein. In other embodiments, compounds described herein contain one or more chiral centers. These compounds are prepared by any means, including stereoselective synthesis, enantioselective synthesis and / or separation of a mixture of enantiomers and / or diastereomers. Resolution of compounds and isomers thereof is achieved by any means including, by way of non-limiting example, chemical processes, enzymatic processes, fractional crystallization, distillation, and chromatography.

[0119] The methods and formulations described herein include the use of N-oxides (if appropriate), crystalline forms (also known as polymorphs), solvates, amorphous phases, and / or pharmaceutically acceptable salts of compounds having the structure of any compound(s) described herein, as well as metabolites and active metabolites of these compounds having the same ty pe of activity. Solvates include water, ether (e.g., tetrahydrofuran, methyl tert-butyl ether) or alcohol (e.g, ethanol) solvates, acetates and the like. In certain embodiments, the compounds described herein exist in solvated forms with pharmaceutically acceptable solvents such as water, and ethanol. In other embodiments, the compounds described herein exist in unsolvated form. In certain embodiments, the compound(s) described herein can exist as tautomers. All tautomers are included within the scope of the compounds presented herein.

[0120] In certain embodiments, compounds described herein are prepared as prodrugs. A “prodrug” refers to an agent that is converted into the parent drug in vivo. In certain embodiments, upon in vivo administration, a prodrug is chemically converted to the biologically, pharmaceutically or therapeutically active form of the compound. In other embodiments, a prodrug is enzymatically metabolized by one or more steps or processes to the biologically, pharmaceutically or therapeutically active form of the compound.

[0121] In certain embodiments, sites on, for example, the aromatic ring portion of compound(s) described herein are susceptible to various metabolic reactions. Incorporation of appropriate substituents on the aromatic ring structures may reduce, minimize or eliminate this metabolic pathway. In certain embodiments, the appropriate substituent to decrease or eliminate the susceptibility of the aromatic ring to metabolic reactions is, by way of example only, a deuterium, a halogen, or an alkyl group.

[0122] Compounds described herein also include isotopically -labeled compounds wherein one or more atoms is replaced by an atom having the same atomic number, but an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes suitable for inclusion in the compounds described herein include and are not limited to2H.3H. “C,13C,14C,36C1,18F,123I,125I,13N,15N,15O,170,180.32P, and35S. In certain embodiments, isotopically-labeled compounds are useful in drug and / or substrate tissue distribution studies. In other embodiments, substitution with heavier isotopes such as deuterium affords greater metabolic stability (for example, increased in vivo half-life or reduced dosage requirements). In yet other embodiments, substitution with positron emitting isotopes, such asnC,18F,15O and13N, is useful in Positron Emission Topography (PET) studies for examining substrate receptor occupancy. Isotopically-labeled compounds are prepared by any suitable method or by processes using an appropriate isotopically-labeled reagent in place of the non-labeled reagent otherwise employed.

[0123] In certain embodiments, the compounds described herein are labeled by other means, including, but not limited to. the use of chromophores or fluorescent moieties, bioluminescent labels, or chemiluminescent labels.

[0124] The compounds described herein, and other related compounds having different substituents are synthesized using techniques and materials described herein and as described, for example, in Fieser & Fieser’s Reagents for Organic Synthesis, Volumes 1-17 (John Wiley and Sons, 1991); Rodd’s Chemistry of Carbon Compounds, Volumes 1-5 and Suppiementals (Elsevier Science Publishers, 1989); Organic Reactions, Volumes 1-40 (John Wiley and Sons. 1991), Larock’s Comprehensive Organic Transformations (VCH Publishers Inc., 1989), March, Advanced Organic Chemistry 4thEd., (Wiley 1992); Carey & Sundberg, Advanced Organic Chemistry 4th Ed., Vols. A and B (Plenum 2000,2001), and Green & Wuts, Protective Groups in Organic Synthesis 3rd Ed., (Wiley 1999) (all of which are incorporated by reference for such disclosure). General methods for the preparation of compound as described herein are modified by the use of appropriate reagents and conditions, for the introduction of the various moieties found in the formula as provided herein.

[0125] Compounds described herein are synthesized using any suitable procedures starting from compounds that are available from commercial sources, or are prepared using procedures described herein. In certain embodiments, reactive functional groups, such as hydroxyl, amino, imino, thio or carboxy groups, are protected in order to avoid their unwanted participation in reactions. Protecting groups are used to block some or all of the reactive moieties and prevent such groups from participating in chemical reactions until the protective group is removed. In other embodiments, each protective group is removable by a different means. Protective groups that are cleaved under totally disparate reaction conditions fulfill the requirement of differential removal.

[0126] In certain embodiments, protective groups are removed by acid, base, reducing conditions (such as, for example, hydrogenolysis), and / or oxidative conditions. Groups such as trityl, dimethoxytrityl, acetal and t-butyldimethylsilyl are acid labile and are used to protect carboxy and hydroxy reactive moieties in the presence of amino groups protected with Cbz groups, which are removable by hydrogenolysis, and Fmoc groups, which are base labile. Carboxylic acid and hydroxy reactive moieties are blocked with base labile groups such as, but not limited to, methyl, ethyl, and acetyl, in the presence of amines that are blocked with acid labile groups, such as t-butyl carbamate, or with carbamates that are both acid and base stable but hydrolytically removable.

[0127] In certain embodiments, carboxylic acid and hydroxy reactive moieties are blocked with hydrolytically removable protective groups such as the benzyl group, while amine groups capable of hydrogen bonding with acids are blocked with base labile groups such as Fmoc. Carboxylic acid reactive moieties are protected by conversion to simple ester compounds as exemplified herein, which include conversion to alkyd esters, or are blocked with oxidatively-removable protective groups such as 2,4-dimethoxybenzyl, while co- existing amino groups are blocked with fluoride labile silyl carbamates.

[0128] Allyl blocking groups are useful in the presence of acid- and base- protecting groups since the former are stable and are subsequently removed by metal or pi-acid catalysts. For example, an allyl-blocked carboxylic acid is deprotected with a palladium-catalyzed reaction in the presence of acid labile t-butyl carbamate or base-labile acetate amine protecting groups. Yet another form of protecting group is a resin to which a compound or intermediate is attached. As long as the residue is attached to the resin, that functional group is blocked and does not react. Once released from the resin, the functional group is available to react.

[0129] Other protecting groups, plus a detailed description of techniques applicable to the creation of protecting groups and their removal are described in Greene & Wuts, Protective Groups in Organic Synthesis, 3rd Ed., John Wiley & Sons, New York, NY, 1999, and Kocienski, Protective Groups, Thieme Verlag, New York, NY, 1994, which are incorporated herein by reference for such disclosure.

[0130] The compounds of the present disclosure can be prepared by the general schemes described herein, using synthetic methods known by those skilled in the art. The following examples illustrate non-limiting embodiments of the compound(s) described herein and their preparation.

[0131] In certain illustrative embodiments, abnormal N-heterocyclic carbene (aNHC) ligands of the present disclosure were prepared according to Schemes 1-6, wherein X1, Ra, Rb, and R3are defined w ithin the scope of the present disclosure. In certain embodiments, X1is I, BF4, or PFe. In certain embodiments, Rais H or methyl. In certain embodiments, Rbis H, methyl, or phenyl.

[0132]

[0133] Scheme 2.

[0134] Scheme 6. In certain illustrative embodiments, abnormal N-heterocyclic carbene (aNHC) complexes of the present disclosure were prepared from the corresponding aNHC ligands according to Schemes 7-8.

[0135] Scheme 8.

[0136] Ligands and Catalyst Complexes Thereof

[0137] In one aspect, the present disclosure provides a compound of formula (I): wherein: R1and R2are each independently selected from the group consisting of optionally substituted C6-C10 ary l, optionally substituted C2-C8 heteroaryl, optionally substituted C3-C8 cycloalkyl, or C2-C8 heterocycloalkyl, wherein at least one C6-C10 aryl or C2-C8 heteroaryl of R1or R2. if present, is substituted at one or two ortho positions thereof with -CH(optionally substituted C6-C10 aryl)2, and wherein at least one C3-C8 cycloalkyl or C2-C8 heterocycloalkyl of R1or R2, if present, comprises a quaternary carbon atom;

[0138] R3is selected from the group consisting of optionally substituted C1-C6 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C2-C8 heterocycloalkyl, optionally substituted C6-C10 aryl, and optionally substituted C2-C8 heteroaryl;

[0139] X1is a monovalent counter anion; each occurrence of optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, and optionally substituted heteroaryl, is independently optionally substituted with at least one selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, CN. NO2, ORA. N(RA)(RB). C(=O)RA, C(=O)N(RA)(RB), C(=O)ORB, N(RA)S(=O)2RB, S(=O)2N(RA), C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyl, wherein the C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyl are each optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyd, C2-C6 alkenyl, benzy l, phenyl, naphthyl, and pyridyl; and

[0140] RAand RBare each independently selected from the group consisting of H, C1-C6 alkyl, C1-C3 haloalkyl, C2-C6 alkenyl, benzyl, naphthyl, C4-C10 heteroaryl, and phenyl, wherein each substituent in RAand RBis optionally substituted with at least one substituent selected from the group consisting of CN, NO2, C1-C3 haloalky l, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, and halogen.

[0141] In certain embodiments, R1is: wherein:

[0142] Rla, Rlh, Rlc, Rld, and Rleare each independently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of Rla, Rlb, Rlc, Rld, and Rleis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0143] In certain embodiments, Rlais H. In certain embodiments, Rlais methyl. In certain embodiments, Rlais isopropyl. In certain embodiments. Rlais diphenylmethyl.

[0144] In certain embodiments, Rlbis H. In certain embodiments, Rlbis methyl. In certain embodiments, Rlbis isopropyl. In certain embodiments. Rlbis diphenylmethyl.

[0145] In certain embodiments, Rlcis H. In certain embodiments, Rlcis methyl. In certain embodiments, Rlcis isopropyl. In certain embodiments, Rlcis diphenylmethyl.

[0146] In certain embodiments, Rldis H. In certain embodiments, Rldis methyl. In certain embodiments, Rldis isopropyl. In certain embodiments, Rldis diphenylmethyl.

[0147] In certain embodiments, Rleis H. In certain embodiments, Rleis methyl. In certain embodiments, R16is isopropyl. In certain embodiments. Rleis diphenylmethyl.

[0148] In certain embodiments, Rlband Rldare independently H. In certain embodiments, Rlb, Rlc, and Rldare each independently H. In certain embodiments, Rlaand Rleare identical. In certain embodiments, R1a. R1c, and Rleare identical. In certain embodiments, Rlaand Rleare each independently optionally substituted C1-C6 alkyl, and Rlb, Rlc. and Rldare H. In certain embodiments, Rla, Rlc, andRleare each independently optionally substituted C1-C6 alkyl, and Rlband Rldare H.

[0149] In certain embodiments, certain embodiments, R1is

[0150] SY

[0151] In certain embodiments, R2is: wherein:

[0152] R2a. R2b, R2C, R2d, and R2eare each independently selected from the group consisting of H. halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of R2a, R2b, R2c, R2d, and R2eis independently selected from the group consisting of halogen, C1-Cs haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0153] In certain embodiments, R2ais H. In certain embodiments, R2ais methyl. In certain embodiments, R2ais isopropyl. In certain embodiments, R2ais diphenylmethyl. In certain embodiments, R2bis H. In certain embodiments, R2bis methyl. In certain embodiments, R2bis isopropyl. In certain embodiments, R2bis diphenylmethyl. In certain embodiments, R2cis H. In certain embodiments, R2cis methyl. In certain embodiments, R2cis isopropyl. In certain embodiments, R2cis diphenylmethyl. In certain embodiments, R2dis H. In certain embodiments, R2dis methyl. In certain embodiments, R2dis isopropyl. In certain embodiments, R2dis diphenylmethyl. In certain embodiments, R2eis H. In certain embodiments, R2eis methyl. In certain embodiments, R2eis isopropyl. In certain embodiments, R2eis diphenylmethyl.

[0154] In certain embodiments, R2a, R2b, R2c, R2d, and R2eare each independently H. In certain embodiments, R2band R2dare independently H. In certain embodiments, R2b. R2c, and R2dare each independently H. In certain embodiments, R2aand R2eare identical. In certain embodiments, R2a, R2c, and R2eare identical.

[0155] In certain embodiments, R2aand R2eare each independently optionally substituted C1- C6 alkyl, and R2b, R2c, and R2dare H. In certain embodiments, R2a, R2c, and R2eare each independently optionally substituted C1-C6 alkyl, and R2band R2dare H.

[0156] In certain embodiments, R2is . In certain embodiments, R2is certain embodiments, certain embodiments,

[0157] In certain embodiments, certain certain embodiments. R1is

[0158]

[0159] In certain embodiments, R3is methyl. In certain embodiments, R3is isopropyl. In certain embodiments, R3is phenyl. In certain embodiments, R3is 2,6-diisopropylphenyl. In certain embodiments, X1is selected from the group consisting of halogen,

[0160] OS(=O)2RA, OC(=O)RAN(C(=O)RA)2. tetracoordmate boronate. and hexacoordinate phosphorus.

[0161] In certain embodiments, X1is I. In certain embodiments, X1is BF4. In certain embodiments, X1is PFe.

[0162] In certain embodiments, the compound of formula (I) is:

[0163] In certain embodiments, the compound of formula (I) is:

[0164] In certain embodiments, the compound of formula (I) is:

[0165] In certain embodiments, the compound of formula (I) is:

[0166] In certain embodiments, the compound of formula (I) is:

[0167] In certain embodiments, the compound of formula (I) is:

[0168] In certain embodiments, the compound of formula (I) is:

[0169] In certain embodiments, the compound of formula (I) is:

[0170] In certain embodiments, the compound of formula (I) is: In certain embodiments, the compound of formula (I) is:

[0171] In certain embodiments, the compound of formula (I) is:

[0172] In certain embodiments, the compound of formula (I) is:

[0173] In another aspect, the present disclosure provides a compound of formula (II): wherein:

[0174] M is a transition metal;

[0175] R1and R2are each independently selected from the group consisting of optionally substituted C6-C10 aryl, optionally substituted C2-C8 heteroaryl, optionally substituted C3-C8 cycloalkyl, or C2-C8 heterocycloalkyl. wherein at least one C6-C10 aryl or C2-C8 heteroaryl of R1or R2, if present, is substituted at one or two ortho positions thereof with -CH(optionally substituted C6-C10 aryl)2, and wherein at least one C3-C8 cycloalkyl or C2-C8 heterocycloalkyl of R1or R2, if present, comprises a quaternary carbon atom; R3is selected from the group consisting of optionally substituted C1-C6 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C2-C8 heterocycloalkyl, optionally substituted C6-C10 aryl, and optionally substituted C2-C8 heteroaryl;

[0176] L is a ligand of M, wherein each occurrence of L can be the same or different;

[0177] X2is a monovalent or divalent counter anion, wherein L and X2can be present in a single compound; each occurrence of optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, and optionally substituted heteroaryl, is independently optionally substituted with at least one selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, CN, NO2, ORA, N(RA)(RB). C(=O)RA, C(=O)N(RA)(RB), C(=O)ORB, N(RA)S(=O)2RB, S(=O)2N(RA), C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyl, wherein the C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyl are each optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzy l, phenyl, naphthyl, and pyridyl;

[0178] RAand RBare each independently selected from the group consisting of H, C1-C6 alkyl, C1-C3 haloalkyl, C2-C6 alkenyl, benzyl, naphthyl. C4-C10 heteroaryl, and phenyl, wherein each substituent in RAand RBis optionally substituted with at least one substituent selected from the group consisting of CN, NO2, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, and halogen; m is selected from the group consisting of 0. 1, 2, and 3; and n is selected from the group consisting of 0, 1, and 2.

[0179] In certain embodiments, R1is: wherein:

[0180] Rla. Rlb, Rlc, Rld, and Rleare each independently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of Rla, Rlb, Rlc, Rld, and Rleis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1-

[0181] C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0182] In certain embodiments, Rlais H. In certain embodiments, Rlais methyl. In certain embodiments, Rlais isopropyl. In certain embodiments, Rlais diphenylmethyl.

[0183] In certain embodiments, Rlbis H. In certain embodiments, Rlbis methyl. In certain embodiments, Rlbis isopropyl. In certain embodiments. Rlbis diphenylmethyl.

[0184] In certain embodiments, Rlcis H. In certain embodiments, Rlcis methyl. In certain embodiments, Rlcis isopropyl. In certain embodiments, Rlcis diphenylmethyl.

[0185] In certain embodiments, Rldis H. In certain embodiments, Rldis methyl. In certain embodiments, Rldis isopropyl. In certain embodiments. Rldis diphenylmethyl.

[0186] In certain embodiments, Rleis H. In certain embodiments, Rleis methyl. In certain embodiments, Rleis isopropyl. In certain embodiments, Rleis diphenylmethyl.

[0187] In certain embodiments, Rlband Rldare independently H. In certain embodiments, Rlb, Rlc, and Rldare each independently H. In certain embodiments, Rlaand Rleare identical. In certain embodiments, Rla, Rlc, and Rleare identical. In certain embodiments, Rlaand Rleare each independently optionally substituted C1-C6 alkyl, and Rlb, Rlc, and Rldare H. In certain embodiments, Rla, Rlc, and Rleare each independently optionally substituted C1-C6 alkyl, and Rlband Rldare H.

[0188] In certain embodiments, R2is: wherein:

[0189] R2a. R2b, R2c. R2d, and R2eare each independently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of R2a. R2b, R2c, R2d. and R2eis independently selected from the group consisting of halogen, C1-C3 haloalkyL C1-

[0190] Cs alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0191] In certain embodiments, R2ais H. In certain embodiments, R2ais methyl. In certain embodiments, R2ais isopropyl. In certain embodiments. R2ais diphenylmethyl. In certain embodiments, R2bis H. In certain embodiments, R2bis methyl. In certain embodiments, R2bis isopropyl. In certain embodiments, R2bis diphenylmethyl. In certain embodiments, R2cis H. In certain embodiments, R2cis methyl. In certain embodiments, R2cis isopropyl. In certain embodiments, R2cis diphenylmethyl. In certain embodiments, R2dis H. In certain embodiments, R2dis methyl. In certain embodiments, R2dis isopropyl. In certain embodiments, R2dis diphenylmethyl. In certain embodiments, R2eis H. In certain embodiments, R2eis methyl. In certain embodiments, R2eis isopropyl. In certain embodiments, R2eis diphenylmethyl.

[0192] In certain embodiments, R2a, R2b, R2c, R2d, and R2eare each independently H. In certain embodiments, R2band R2dare independently H. In certain embodiments, R2b, R2c, and R2dare each independently H. In certain embodiments, R2aand R2eare identical. In certain embodiments, R2a, R2c, and R2eare identical.

[0193] In certain embodiments, R2aand R2eare each independently optionally substituted C1- Ce alkyl, and R2b, R2c, and R2dare H. In certain embodiments, R2a, R2c, and R2eare each independently optionally substituted C1-C6 alkyl, and R2band R2dare H.

[0194] In certain embodiments, R2is . In certain embodiments, R2is . In certain embodiments, certain embodiments,

[0195] In certain embodiments,

[0196] In certain embodiments, R3is methyl. In certain embodiments, R3is isopropyl. In certain embodiments, R3is phenyl. In certain embodiments, R3is 2,6-diisopropylphenyl.

[0197] In certain embodiments, M is Pd. In certain embodiments, M is Cu. In certain embodiments, M is Ag. In certain embodiments, M is Au. In certain embodiments, M is Ni. In certain embodiments, M is Pt. In certain embodiments, M is Co. In certain embodiments, M is Rh. In certain embodiments, M is Ir. In certain embodiments, M is Fe. In certain embodiments, M is Ru. In certain embodiments, M is Os.

[0198] In certain embodiments, L is selected from the group consisting of carbon monoxide (CO), optionally substituted C2-C12 alkene, and optionally substituted C5-C12 cycloalkene, optionally substituted benzylamine, optionally substituted C2-C8 heteroaryl, wherein each optional substituent in the C2-C12 alkene, C5-C12 cycloalkene, benzylamine, and C2-C8 heteroaryl is independently selected from the group consisting of a halogen, CN, NO2, C1-Cr- haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C3-C8 cycloalkyl, phenyl, and C2-C8 heterocyclyl.

[0199] In certain embodiments, L is carbon monoxide (CO). In certain embodiments, L is cyclooctadiene (COD). In certain embodiments, L is (1-phenylpropenide and l-phenylprop-2-en-l-ide; double bond thereof).

[0200] In certain embodiments, each X2is independently selected from the group consisting of halogen. OS(=O)2RA, OC(=O)RA, N(C(=0)RA)2, optionally substituted allyl anion, tetracoordinate boronate, and hexacoordinate phosphorus. In certain embodiments, X2is Cl. In certain embodiments, X2is I. In certain embodiments, X2is (1-phenylpropenide and l-phenylprop-2-en-l-ide; anion thereof).

[0201] In certain embodiments, the compound of formula (II) is:

[0202] In certain embodiments, the compound of formula (II) is:

[0203] In certain embodiments, the compound of formula (II) is: In certain embodiments, the compound of formula (II) is:

[0204] In certain embodiments, the compound of formula (II) is:

[0205] In certain embodiments, the compound of formula (II) is:

[0206] In certain embodiments, the compound of formula (II) is:

[0207] In certain embodiments, the compound of formula (II) is:

[0208] In certain embodiments, the compound of formula (II) is:

[0209] In certain embodiments, the compound of formula (II) is:

[0210] In certain embodiments, the compound of formula (II) is:

[0211] In certain embodiments, the compound of formula (II) is:

[0212] In certain embodiments, the compound of formula (II) is:

[0213] In certain embodiments, the compound of formula (II) is: In certain embodiments, the compound of formula (II) is:

[0214] In certain embodiments, the compound of formula (II) is:

[0215] In certain embodiments, the compound of formula (II) is:

[0216] In certain embodiments, the compound of formula (II) is:

[0217] In certain embodiments, the compound of formula (II) is: )(cin)I]).

[0218] In certain embodiments, the compound of formula (II) is:

[0219]

[0220] In certain embodiments, the compound of formula (II) is: (cin)Cl] ).

[0221] In certain embodiments, the compound of formula (IT) is:

[0222] In certain embodiments, the compound of formula (II) is:

[0223] In certain embodiments, the compound of formula (II) is:

[0224] In certain embodiments, the compound of formula (II) is:

[0225] In certain embodiments, the compound of formula (II) is:

[0226] In certain embodiments, the compound of formula (II) is: )(cod)Cl]).

[0227] In certain embodiments, the compound of formula (II) is: (cod)Cl]).

[0228] In certain embodiments, the compound of formula (II) is: )(cod)Cl]).

[0229] In certain embodiments, the compound of formula (II) is: (cod)Cl]).

[0230] Methods

[0231] In another aspect, the present disclosure provides a method of promoting an intramolecular cyclization of a compound comprising a terminal alkyne and a carboxylic acid, the method comprising contacting the compound comprising the terminal alkyne and the carboxylic acid with at least one compound of formula (II). In certain embodiments, the contacting occurs in the presence of a Lewis acid. In certain embodiments, the Lewis acid is sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, which is also known as NaBArF4. In certain embodiments, M is Au. In certain embodiments, M is Cu.

[0232] In another aspect, the present disclosure provides a method of promoting a reaction between an alkyne and an aniline, the method comprising contacting the alkyne and the aniline with at least one compound of formula (II). In certain embodiments, the contacting occurs in the presence of a Lewis acid. In certain embodiments, the Lewis acid is NaBArF4. In certain embodiments, M is Au.

[0233] In another aspect, the present disclosure provides a method of promoting an intramolecular cyclization of a compound comprising a propargyl amide, the method comprising contacting the propargyl amide with at least one compound of formula (II). In certain embodiments, the contacting occurs in the presence of a Lewis acid. In certain embodiments, the Lewis acid is AgOTf. In certain embodiments, M is Au.

[0234] In another aspect, the present disclosure provides a method of promoting a reaction between an alkyne and an arene, the method comprising contacting the alkyne and the arene w ith at least one compound of formula (II). In certain embodiments, the contacting occurs in the presence of a Lewis acid. In certain embodiments, the Lewis acid is NaBArF4. In certain embodiments, M is Au.

[0235] In another aspect, the present disclosure provides a method of promoting a reaction between an alkyne and an alkene, the method comprising contacting the alkyne and the alkene with at least one compound of formula (II). In certain embodiments, the contacting occurs in the presence of a Lewis acid. In certain embodiments, the Lewis acid is NaBArF4. In certain embodiments, M is Au.

[0236] In another aspect, the present disclosure provides a method of promoting hydration of an alkyne, the method comprising contacting the alkyne and an aniline with at least one compound of formula (II). In certain embodiments, the contacting occurs in the presence of a Lewis acid. In certain embodiments, the Lewis acid is NaBArF4. In certain embodiments, M is Cu.

[0237] In another aspect, the present disclosure provides a method of promoting hydrosilylation of a ketone, the method comprising contacting the ketone and a trialkoxysilane, w ith at least one compound of formula (II) and a base. In certain embodiments, the base is an alkoxide base. In certain embodiments, M is Cu.

[0238] In another aspect, the present disclosure provides a method of promoting borylation of an alkene, the method comprising contacting the alkene and a borylating agent with at least one compound of formula (II) and a base. In certain embodiments, the borylating agent is bis(pinacolato)diboron (B2pin2). In certain embodiments, base is an alkoxide base. In certain embodiments, M is Cu.

[0239] In another aspect, the present disclosure provides a method of promoting borylation of an alkyne, the method comprising contacting the alkyne and a borylating agent with at least one compound of formula (II) and a base. In certain embodiments, the bory lating agent is bis(pinacolato)diboron (B2pin2). In certain embodiments, the base is an alkoxide base. In certain embodiments, M is Cu. In certain embodiments, M is Ag.

[0240] In another aspect, the present disclosure provides a method of promoting a reduction of an alky ne, the method comprising contacting the alkyne and a reducing agent with at least one compound of formula (II) and a base. In certain embodiments, the base is an alkoxide base. In certain embodiments, the contacting further occurs in the presence of an alcohol. In certain embodiments, the reducing agent is a silane. In certain embodiments, the silane is polymethylhydrosiloxane (PHMS). In certain embodiments, M is Cu.

[0241] In another aspect, the present disclosure provides a method of promoting oxidation of an aldehyde, the method comprising contacting the aldehyde and a base in the presence of O2 (g) with at least one compound of formula (II). In certain embodiments, the contacting occurs in the presence of an alcohol. In certain embodiments, the base is an alkoxide base. In certain embodiments, M is Cu.

[0242] In another aspect, the present disclosure provides a method of promoting oxidation of an alcohol, the method comprising contacting the alcohol and a base in the presence of O2 (g) with at least one compound of formula (II). In certain embodiments, the base is a hydroxide base. In certain embodiments, M is Cu.

[0243] In another aspect, the present disclosure provides a method of promoting a reaction between an aryl halide or heteroaryl halide and an amine, the method comprising contacting the aryl halide or heteroaryl halide and the amine with at least one compound of formula (II) and a base. In certain embodiments, the halide is a chloride. In certain embodiments, the base is an alkoxide base. In certain embodiments, M is Pd.

[0244] In another aspect, the present disclosure provides a method of promoting an oxidation of an alkene, the method comprising contacting the alkene and an oxidizing agent with at least one compound of formula (II). In certain embodiments, the oxidizing agent is a peroxide. In certain embodiments, M is Pd.

[0245] In another aspect, the present disclosure provides a method of promoting hydrogenation of an arene or heteroarene, the method comprising contacting the arene or heteroarene and H2 (g) with at least one compound of formula (II). In certain embodiments, M is Ir. In certain embodiments, M is Rh.

[0246] In certain embodiments, the terminal alkyne and carboxylic acid are covalently linked by a C2-C6 alkylenyl which is optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C6 alkyl, C1-C6 alkoxy, C3-C8 cycloalkyl, C3-C8 cycloalkoxy, CN, and NO2, wherein the C1-C6 alkyl, C1-C6 alkoxy, C3-C8 cycloalkyl, and C3- Cs cycloalkoxy are each independently optionally substituted with at least one selected from the group consisting of halogen, CN, NO2, C1-C3 alkoxy, C1-C3 haloalkyl, and C1-C3 haloalkoxy.

[0247] In certain embodiments, the alkyne is a C2-C6 alky ne, wherein the C2-C6 alkyne is optionally substituted with at least one substituent selected from the group consisting of C1- Ce alkoxy, C1-C6 haloalkoxy, C1-C6. haloalkyl, C1-C6 alkyl. C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl, wherein each C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyd, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl is optionally substituted with at least one selected from the group consisting of NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N( C1-C6 alkyl)2.

[0248] In certain embodiments, the aniline is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroaryl is substituted with at least one NH2 moiety, and further optionally substituted with at least one substituent selected from the group consisting of C1- Ce alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl. NH2, N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH. C(=O)O(C1-C6 alkyl), C(=O)NH2. C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2.

[0249] In certain embodiments, the propargyl amide is a C6-C10 aryl or C2-C8 heteroaryl, wherein the Ce-C 10 aryl or C2-C8 heteroaryl is substituted with at least one - C(=O)NHCH2C=CH moiety, and further optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1- Ce alkyl, C3-C12 cycloalkyd, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1- Ce alkyl)2, halogen, OH, CN, NO2, C(=O)OH. C(=O)O( C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2.

[0250] In certain embodiments, the arene or heteroarene is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroary l is optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2. C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2.

[0251] In certain embodiments, the alkene is a C2-C6 alkene, wherein the C2-C6 alkene is optionally substituted with at least one substituent selected from the group consisting of C1- Ce alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl, wherein each C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl is optionally substituted with at least one selected from the group consisting of NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen. OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2.

[0252] In certain embodiments, the ketone is R'C(=O)R’', wherein R’ and R” are each independently selected from the group consisting of C1-C6 alkyl, C3-C8 cycloalkyd. C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl, wherein the C1-C6 alkyd, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 ary l, and C2-C8 heteroaryl are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyd), and C(=O)N(C1-C6 alkyl)2.

[0253] In certain embodiments, the aldehyde is R C(=O)H. wherein R’ is selected from the group consisting of C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyd, C6-C10 aryl, and C2-C8 heteroaryl, wherein the C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyd, C6-C10 aryl, and C2-C8 heteroary 1 are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy. C1-C6 haloalkoxy, C1-C6, haloalkyl, C1- Ce alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyd), N( C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6alkyd), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alky d)2.

[0254] In certain embodiments, the alcohol is R’CH20H, wherein R' is selected from the group consisting of C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl, wherein the C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 ary l, and C2-C8 heteroary 1 are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1- Ce alkyl, C3-C8 cycloalkyl. C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6alkyd), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyd)2.

[0255] In certain embodiments, the ary 1 halide or heteroaryl halide is a C6-C10 ary l or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroary ! is substituted with at least one halogen selected from the group consisting of Cl, Br, and I, and further optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyd, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1-C6 alkyl)2, halogen, OH, CN. NO2. C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2. C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2.

[0256] EXAMPLES

[0257] Various embodiments of the present application can be better understood by reference to the following Examples which are offered by way of illustration. The scope of the present application is not limited to the Examples given herein. Example 1: Ligand Synthesis

[0258] Synthesis of Symmetrical MIC-IPr * IPr* HI / HBF4

[0259] 2,6-Dibenzhydryl-4-methylaniline. Toluidine (7.5 g, 70 mmol, 1.0 equiv) and diphenylmethanol (25.8 g, 140 mmol, 2.0 equiv) were charged in an oven-dried 100 mL pressure tube with a stir bar in it. The pressure tube was then placed in an oil bath at 100 °C and melted together. After that, anhydrous ZnCh (4.77 g, 35 mmol, 0.5 equiv) and HC1 (aq., 36%, 6 mL, 1.0 equiv) were added respectively into the melt, and the reaction was heated at 160 °C for 4 h. The reaction was cooled down to room temperature, the solid w-as dissolved in 200 mL of CH2CI2 and washed sequentially with saturated NaHCOs solution and brine. After drying over anhydrous Na2SO4, the solution was evaporated to dryness to yield 2,6- dibenzhydryl-4-methylaniline as a white powder in 92% (28.3 g) yield. The resulting product was used directly in the next step without further purification, 'l l NMR (500 MHz,CDCI3) 8 7.29 (t, J = 7.3 Hz, 8H), 7.23 (t, J = 7.3 Hz, 4H), 7.11 (d, J = 7.2 Hz, 8H). 6.40 (s, 2H), 5.47 (s, 2H), 3.34 (s, 2H), 2.04 (s, 3H).13C NMR (126 MHz, CDCI3) δ 142.9, 139.8, 129.7, 129.4, 129.2, 128.6, 126.8, 126.7, 52.5, 21.1.

[0260] ((2-Azido-5-methyl-l,3-phenylene)bis(methanetriyl))tetrabenzene. An oven-dried 500 mL round-bottomed flask equipped with a stir bar was charged with 2,6-dibenzhydryl-4- methylaniline (18.6 g, 40 mmol, 1.0 equiv) and was dissolved in 250 mL of CH3CN. The flask was placed in an ice bath to cool to 0°C. After 15 minutes, tBuONO (10.3 g, 11.9 mL, 100 mmol) was added dropwise to this stirred mixture. After 10 min, TMSN3 (8.3 g, 9.47 mL, 72 mmol) was added and the resulting solution was stirred vigorously at room temperature for 3 h. The reaction mixture was concentrated under vacuum and the crude product was washed with hexane and further dried under vacuum to obtain the white solid compound 7 (16.58 g, 89%). The resulting product was used directly in the next step without further purification. 1H NMR (500 MHz, CDCI3 ) δ 7.29 (t, J = 7.4 Hz, 8H), 7.22 (t, J = 7.3 Hz. 4H), 7.09 (d. J = 7.3 Hz. 8H), 6.60 (s, 2H), 5.86 (s, 2H), 2. 12 (s, 3H).13C NMR (126 MHz,CDCI3 ) δ 143.2, 139.4, 135.8, 134.7, 129.7, 129.6, 128.5, 126.7, 52.4, 21.6.

[0261] ((2-Iodo-5-inethyl-l,3-phenylene)bis(methanetriyl))tetrabenzene. 2.6- dibenzhydryl-4-methylamline (17.6 g. 40 mmol) was added to a suspension of p-TsOH H2O (34.24 g, 180 mmol) in a mixture of tBuOH (220 mL), acetonitrile (220 mL) and water (10 mL), and the mixture was placed on an ice bath. After 15 minutes, a solution of NaNCh (8.3 g, 120 mmol) and KI (24.9 g, 150 mmol) in water (35 mL) was then added dropwise during 2 hr, keeping the temperature of the mixture less than 10 °C. After the addition, the mixture was allowed to come at room temperature and was stirred for an additional 8 hr. After completion of the reaction, NaHCO- (15 g) was then added to bring the mixture to pH 9-10, followed by solid Na2S2O3 (40 g). Upon vigorous stirring for 30 min, the color of the solution turned deep purple to yellow, and then LO L water was mixed into it. The mixture was extracted with Et20 and the combined extracts were washed with water and brine, and dried with anhydrous Na2SO4. The mixture was then evaporated and subjected to the silica gel column chromatography to give pale yellow ((2-iodo-5-methyl-l,3- phenylene)bis(methanetriyl))tetrabenzene (13.2 g. 24 mmol, 60%) as product. 1H NMR (500 MHz,CDCI3 ) 6 7.30 - 7.27 (m, 8H), 7.24 - 7.22 (m, 4H). 7.07 - 7.06 (m, 8H). 6.61 (s. 2H), 6.02 (s, 2H), 2.10 (s, 3H).13C NMR (126 MHz, CDCI3) δ 147.2, 143.4, 137.1, 130.4, 130.0, 128.4, 126.5, 108.2, 62.1, 21.3. HRMS (APCI): calcd for C33H31IN [M + NH4]+ 568.1496, found 568.1501.

[0262] ((2-Ethynyl-5-methyl-l,3-phenylene)bis(methanetriyl))tetrabenzene. An oven- dried 100 mL round-bottomed flask equipped with a stir bar was charged with ((2-iodo-5- methyl-1,3- phenylene)bis(methanetriyl))tetrabenzene (5.50 g, 10 mmol), trans dichlorobis(triphenylphosphine)palladium(II) (351 mg, 0.5 mmol), copper(I) iodide (133 mg, 0.7 mmol) under the Argon atmosphere. After that, 40 mL of 3: 1 (v / v) degassed toluene: diisopropylamine was added to the mixture, followed by the slow addition of ethynyltriisopropylsilane (5.47 g, 6.73 mL, 30 mmol). The reaction mixture was then placed in an oil bath and allowed to stir at 65°C for 12 h. After the completion of the reaction, the yellow precipitate was filtered out and the eluent was evaporated under the reduced pressure. The black solid product was then passed through a short S1O2 column using ethyl acetate as eluent to deliver white solid crude TIPS -protected alkyne product ((2,6-dibenzhydryl-4- methylphenyl)ethynyl)triisopropylsilane. The product was then dissolved in 20 mL of THF followed by 20 mL of TBAF solution (IM in THF). After 15 minutes of stirring, the solvent was evaporated, then diluted again with 50 mL of DCM and quenched with 25 ml of H2O. The organic layer was further extracted with brine and dried overNa2SO4,. The mixture was evaporated under reduced pressure to give the crude white solid product which was further washed with hexane twice to give the deprotected-alkyne product ((2-ethynyl-5-methyl-l,3- phenylene)bis(methanetriyl))tetrabenzene (3.77 g. 84%). 1H NMR (500 MHz, CDCI3) δ 7.38- 7.22 (m, 8H), 7.28 - 7.25 (m, 4H), 7.15 (d, J = 7.3 Hz, 8H), 6.74 (s, 2H), 6.17 (s, 2H), 3.37 (s, 1H), 2.22 (s, 3H).13C NMR (126 MHz, ) δ 146C.9D, C 14I33.6, 138.1, 129.8, 128.5, 128.3, 126.3, 120.1, 86.6, 80.9, 54.6, 22.1. HRMS (APCI): calcd for C35H29 [M + H]+ 449.2264, found 449.2275. l,4-bis(2,6-Dibenzhydryl-4-methylphenyl)-lH-l,2,3-triazole. An oven-dried 100 mL round-bottomed flask equipped with a stir bar was charged with the corresponding aryl alkyne (3.14 g, 7 mmol) and aryl azide (3.58 g, 7.7 mmol), CuSO4 (279 mg, 1.75 mmol) and sodium ascorbate (832 mg, 4.2 mmol) under air. After that, 50 mL of 3:2: 1 (v / v) degassed THF:MeCN:H2O was added to the mixture and was allowed to heat at 80 °C for 4 days. After, completion of the reaction, an excess of cone. aq. NH4OH was added to quench the reaction and the resulting mixture was further stirred for 30 min. Then, the mixture was evaporated under reduced pressure, diluted and extracted with CH2CI2 and the combined organic fractions w ere dried over anh. Na2SO4,. After evaporation of the solvent, the crude product was washed with hexane, to yield the title triazole product as a white solid (4.97 g, 78%). 1H NMR (500 MHz, CD)C 6I 73.22 (t, J = 7.3 Hz, 4H). 7.19 - 7.16 (m, 2H), 7.09 - 7.04 (m, 12H), 6.99 - 7.95 (m, 6H), 6.89 (t, J = 7.5 Hz, 4H), 6.84 (s, 2H), 6.76 - 7.70 (m, 10H), 6.53 (d, J = 7.5 Hz, 4H), 6.23 (s, 1H), 5.60 (s, 2H), 4.89 (s, 2H), 2.23 (s, 3H), 2.18 (s, 3H).13C NMR (126 MHz, CDCI314I34.1, 143.42, 143.40, 143.3, 141.9, 140.8, 139.6, 137.6, 132.6, 130.1. 129.6, 129.42, 129.40, 128.9, 128.3. 128.2, 128.1, 127.1, 126.8, 126.5, 126.4, 126.0, 52.9, 50.7, 21.92. 21.88. HRMS (APCI): calcd for CssHseNs [M + H]+ 914.4469, found 914.4439.

[0263] 3,5-bis(2,6-Dibenzhydryl-4-methylphenyl)-l-methyl-lH-l,2,3-triazol-3-ium iodide,

[0264] MIC-IPr* / IPr*Me-HI. In an oven-dried 100 mL round-bottomed flask, the corresponding triazole (5.0 g, 5.47 mmol) was taken and dissolved in 15 ml of CHsCN. Methylating agent CH3I (10 equiv) was added to the mixture and allowed to stir at 70 °C for 2 days. After the completion of the reaction, the solvent was evaporated and washed with diethyl ether 3-4 times to give the pure product. Yield = 96% (5.57 g).1H NMR (500 MHz, ) δ 9.83 (s, CDCI3 1H), 7.26 - 7.17 (m . 25H), 7.11 - 7.09 (d, J = 7.0 Hz, 4H), 6.92 - 6.91 (m. 9H), 6.86 - 6.85 (m, 4H), 6.84 (s, 2H), 5.02 (s, 2H), 4.82 (s, 2H), 2.26 (s, 3H), 2.23 (s, 3H), 2. 19 (s, 3H).13C NMR (126 MHz, CDCI δ313C NMR (126 MHz, ) δ 1C45D.2C,I3143.6, 143.3, 141.9, 141.6,

[0265] 140.8, 140.7, 140.2, 134.20, 134.17, 131.2, 130.6, 130.4, 129.6, 129.5, 129.4, 129.3, 128.9,

[0266] 128.8, 128.3. 127.8, 127.6, 127.5, 127.2, 117.2, 54.4, 51.5, 37.1, 22.18. 22.17. HRMS (APCI): calcd for C69H58N3 |M - IJ+ 928.4625. found 928.4621. l,4-bis(2,6-Dibenzhydryl-4-methylphenyl)-3-methyl-lH-l,2,3-triazol-3-ium tetrafluoroborate, MIC-IPr* / IPr*Me-HBF4. In an oven-dried 25 mL round-bottomed flask, the corresponding triazole (457.1 mg, 0.5 mmol) was taken and dissolved in 5 ml of CH3CN. Methylating agent Me3OBF4 (4.0 equiv) was added to the mixture and allowed to stir at room temperature for 48 h. After the completion of the reaction, the solvent was evaporated, and the residue was dissolved into 10 mL of DCM, followed by the addition of 2 rnL of H2O. After the workup, the mixture dried over Na2SO4, evaporated to dryness and washed with diethyl ether 2-3 times to give the pure product. Yield = 86% (438 mg). 1H NMR (500 MHz, CDCI3 δ 9.06 (s, 1H). 7.25 - 7.14 (m. 25H), 7.04 (d, J = 7.2 Hz, 4H), 6.97 - 6.92 (m, 6H). 6.87 - 6.86 (m, 7H), 6.83 (s, 2H), 4.98 (s, 2H), 4.82 (s, 2H), 2.26 (s, 3H), 2.22 (s, 3H), 2.19 (s, 3H).13C NMR (126 MHz, CDCI3) δ 145.2, 143.5, 143.1, 142.1, 142.0, 141.9, 140.9, 140.3, 134.2, 131.1, 130.8, 130.3, 129.7, 129.5, 129.4, 129.3, 129.2, 128.9, 128.7, 127.7.

[0267] 127.6, 127.4. 127.1, 117.4, 54.4. 51.5. 36.8, 22.1. HRMS (APCI): calcd for C69H58N3 [M- BFft- 928.4625, found 928.4652.

[0268] Synthesis ofUnsymmetricalMIC-IPr* / Ph HI / HBF4, MIC-IPr*'Mes HI / HBF4, MIC- IPr * / DippHI / HBF4.

[0269] 2-Iodo-l,3,5-trimethylbenzene 2,4,6-Trimethylaniline (10.82 g, 80 mmol) was added to a suspension of p-TsOH H2O (68.5 g, 360 mmol) in a mixture of tBuOH (480 mL) and water (20 mL), and the mixture was placed on an ice bath. After 15 minutes, a solution of NaNCh (16.6 g, 240 mmol) and KI (49.8 g, 300 mmol) in water (70 mL) was then added dropwise over 2 h, keeping the temperature of the mixture less than 10 °C. After the addition, the mixture was allowed to come at room temperature and was stirred for an additional 2 h. After completion of the reaction, NaHCOs (30 g) was added to bring the mixture to pH 9-10, followed by solid Na2S2O3 (80 g). Upon vigorous stirring for 30 min. the color of the solution turned deep purple to yellow; and then 2.0 L water was mixed into it. The mixture was extracted with hexane and the combined extracts were washed with water and brine, and dried with anhydrous Na2SO4. The mixture was then evaporated and subjected to the silica gel column chromatography to give light-yellow solid 2-iodo-l,3,5-trimethylbenzene (16.35 g, 66.4 mmol, 83%) as the product. The iodide was further used without further purification.

[0270] 2-Ethynyl-l ,3,5-trimethylbenzene An oven-dried 250 mL round-botomed flask equipped with a stir bar was charged with mesityl iodide (9.84 g, 40 mmol), bis(triphenylphosphine)palladium(II) di chloride (702 mg, 2.5 mol%) and copper(I) iodide (380 mg, 5 mol%) under the argon-atmosphere. Then. 150 mL degassed THf / ELN was added to the mixture followed by (trimethylsilyl)acetylene (4.32 g, 1.1 equiv). The reaction mixture was stirred for 12 hours at room temperature. After the completion of the reaction, the mixture was filtered through a pad of silica, which was washed with EtOAc. The filtrate was concentrated under reduced pressure and the crude mixture was purified by flash chromatography. An oven dried 100 mL round-bottomed flask, TMS-protected alkyne was dissolved in dry methanol and treated with K2CO3 (11 g, 80 mmol, 2 eq.). The resulting mixture was stirred at room temperature for 2 h. Then, methanol was evaporated and the water was added to the mixture. The aqueous phase was extracted with DCM. The combined organic layers were dried over Na2SOr, filtered and concentrated in vacuum to give the product 2-ethynyl-l,3,5-trimethylbenzene (5.2 g, 90%). The alkyne was further used without any purification. 1H NMR (500 MHz, ) 6.C9D0 C (sI,32H), 3.49 (s, 1H), 2.46 (s, 6H), 2.32 (s, 3H).13C NMR (126 MHZ, )C δDC 14I30.9, 138.2, 127.7, 119.1, 84.7, 81.5, 21.4, 21.0.

[0271] 2-Iodo-l,3-diisopropylbenzene. 2,6-Diisopropylaniline (14.18 g, 80 mmol) was added to a solution of p-TsOH H2O (68.5 g, 360 mmol) in a mixture of tBuOH (480 mL) and water (20 mL), and the mixture was placed on an ice bath. After 15 minutes, a solution of NaNCh (16.6 g, 240 mmol) and KI (49.8 g, 300 mmol) in water (70 mL) was then added dropwise over 2 h, keeping the temperature of the mixture less than 10 °C. After the addition, the mixture was allowed to come at room temperature and was stirred for an additional 2 h. After completion of the reaction, NaHCCh (30 g) was then added to bring the mixture to pH 9-10, followed by solid Na2S2O3 (80 g). Upon vigorous stirring for 30 min, the color of the solution will turn deep purple to yellow, and then 2.0 L water was mixed into it. The mixture was extracted with hexane and the combined extracts were washed with water and brine, and dried with anhydrous Na2SO4. The mixture was then evaporated and subjected to the flash silica gel column chromatography to give 2-iodo-l,3-diisopropylbenzene (14.05 g. 48.8 mmol, 61%) as the product. The iodide was further used without further purification. 'H NMR (500 MHz, CDC)I δ37.24 (t, J = 7.6 Hz, 1H), 7.08 (d, J = 7.6 Hz, 2H), 3.41 (hept, J = 6.8 Hz, 2H), 1.24 (d, J = 6.8 Hz, 12H).13C NMR (126 MHz, ) δ 151.3, C 12D8C.5I,3124.0, 109.3, 39.6, 23.5.

[0272] 2-ethynyl-l,3-diisopropylbenzene. An oven-dried 100 mL round-bottomed flask equipped with a stir bar was charged with 2-iodo- 1,3 -diisopropylbenzene (5.76 g, 20 mmol). trans-dichlorobis(triphenylphosphine)palladium(II) (702 mg, 1 mmol), copper(I) iodide (266 mg, 1.4 mmol) under the Argon atmosphere. After that, 40 mL of 3: 1 (v / v) degassed toluene: diisopropylamine was added to the mixture, followed by the addition of ethynyltrimethylsilane (2.95 g, 4.27 mL, 30 mmol). The reaction mixture was then placed in an oil bath and allowed to stir at 65°C for 12 h. After the completion of the reaction, the black precipitate was filtered out and the eluent was evaporated under the reduced pressure. The black solid product was then passed through a short S1O2 column using hexane as eluent to deliver TIPS -protected alkyne as yellow oil product ((2,6- diisopropylphenyl)ethynyl)trimethylsilane). The crude product was then dissolved in 30 mL of methanol and 5.53 gm of potassium carbonate was added to the mixture. After 2 hours of stirring, the solvent was evaporated and then diluted again with 50 mL of hexane. The organic layer w as extracted H2O, brine and dried overNa2SO4,. The mixture was evaporated under reduced pressure to give the crude yellow product. The crude alkyne was purified bysilica gel column chromatography using pentane as eluent to afford 2-ethyny 1-1,3 - diisopropylbenzene as a colorless oil (2 g, 54%). 1H NMR (500 MHz, ) δ 7.29 (t, J =CDCI3 7.8 Hz, 1H), 7.13 (d, J = 7.7 Hz, 2H), 3.57 - 3.54 (m, 2H), 3.47 (s, 1H), 1.27 (d, J = 6.9 Hz, 12H).13C NMR (126 MHz, )C 1D51C.7I3, 129.0, 122.3, 120.0, 85.2, 80.7, 31.8, 23.4. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-phenyl-lH-l,2,3-triazole. An oven-dried

[0273] 100 mL round-bottomed flask equipped with a stir bar was charged with the corresponding azide (4.66 g, 10 mmol), phenyl acetylene (1.53 g, 15 mmol), CuSCU (319.2 mg, 2.0 mmol) and sodium ascorbate (990.6 mg, 5 mmol) under air. After that. 60 mL of 3:2: 1 (v / v) THF / MeCN / H2O were added to the mixture and allowed to heat at 80 °C for 4 days. After, completion of the reaction, an excess of cone. aq. NFLOH was added to quench the reaction and the resulting mixture was further stirred for 30 min. Then, the mixture was evaporated under reduced pressure, diluted and extracted with CH2CI2 and the combined organic fractions were dried over anhydrous Na2SOr. After evaporation of the solvent, the crude product was washed with hexane, to yield triazole as a white solid (4.8 g, 85%).!H NMR (500 MHz, CDC)I3 δ 7.45 (d, J = 7.5 Hz, 2H), 7.36 - 7.33 (m, 2H), 7.30 - 7.28 (m, 2H), 7.26 - 7.25 (m, 3H), 7.20 (t, J = 7.3 Hz, 2H), 7.15 - 7. 14 (m. 6H), 7.04 (d, J = 7.3 Hz, 4H), 6.85 - 7.83 (m, 4H), 6.81 (s, 2H). 6.15 (s, 1H). 5.12 (s. 2H), 2.26 (s. 3H).13C NMR (126 MHz, CDCh) δ 142.8, 142.5, 142.0, 140.2, 133.3, 130.4, 129.7, 129.4, 129.0, 128.8, 128.52, 128.49, 128.3, 128.2, 128.1, 126.7, 125.8, 51.6, 22.0. HRMS (APCI): ealed for C41H34N3 [M + H]+ 568.2747, found 568.2756. l-(2,6-Dibenzhydryl-4-methylphenyl)-3-methyl-4-phenyl-lH-l,2,3-triazol-3-ium iodide, MIC-IPr* / PhMe-HI. In an oven-dried 100 mL round-bottomed flask, triazole (2.84 g, 5 mmol) was taken and dissolved in 15 ml of CH3CN. Methylating agent CH3I (10 equiv) was added to the mixture and allowed to stir at 70 °C for 2 days. After the completion of the reaction, the solvent was evaporated and washed with diethyl ether 3-4 times to give the pure product (yield = 94%, 3.33 g). (15H0 N0 M MHRz, ) δ 7.56C -D 7C.4I38 (m, 3H), 7.42 (d. J = 7.1 Hz, 2H), 7.38 (s, 1H), 7.28 - 7.22 (m, 10H), 7.16 - 7.12 (m, 6H), 7.07 (d, J = 7.2 Hz, 4H), 6.77 (s, 2H), 5.69 (s, 2H), 4.27 (s, 3H), 2.24 (s, 3H).13C NMR (126 MHz, 142.6, CDCI3 142.3, 141.8, 141.5, 141.0, 132.1, 131.4, 130.80, 129.762, 129.756. 129.7, 129.4, 129.1, 128.7, 127.3. 127.1, 121.0, 51.8. 40.5. 22.1. HRMS (APCI): calcd for C42H36N3 [M]+582.2904, found 582.2881. l-(2,6-Dibenzhydryl-4-methylphenyl)-3-methyl-4-phenyl-lH-l,2,3-triazol-3-iuin tetrafluoroborate, MIC-IPr* / PhMe-HBF4. In an oven-dried 25 mL round-bottomed flask, triazole (1.14 g, 2.0 mmol) was taken and dissolved in 6 ml of dry CH3CN. Methylating agent MesOBFr (10.0 equiv.) was added to the mixture and allowed to stir at room temperature for 48 h. After the completion of the reaction, the solvent was evaporated, and the residue was dissolved into 10 mL of DCM, followed by the addition of 2 mL of H2O. After the workup, the mixture dried overNa2SO4,, evaporated to dryness and washed with diethyl ether 2-3 times to give the pure product to give the title triazolium salt (yield = 83%, 1.1 g).rH NMR (500 MHz. CDC)I3 δ 7.54 - 7.47 (m, 3H). 7.29 - 7.25 (m. 6H), 7.23 - 7.20 (m. 6H), 7.13 (t, J = 7.3 Hz, 2H), 7.02 (d, J = 7.5 Hz, 8H), 6.93 (s, 1H), 6.77 (s, 2H), 5.40 (s, 2H), 4.12 (s, 3H), 2.24 (s, 3H).13C NMR (126 MHz, CDCls) δ 142.6, 142.5, 141.8, 141.5, 141.0, 132.0, 131.0, 130.9, 130.7, 129.7, 129.6, 129.4, 129.2, 129.1, 128.7, 127.4, 127.2, 121.2, 51.9, 39.0, 22.1. HRMS (APCI): calcd for C42H36N3 [M]+582.2904, found 582.2914. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-mesityl-lH-l,2,3-triazole. An oven-dried 100 mL round-bottomed flask equipped with a stir bar was charged with the corresponding azide (4.66 g, 10 mmol), 2-ethynyl-l,3,5-trimethylbenzene (2.15 g, 15 mmol), CuSCh (319 mg, 2.0 mmol) and sodium ascorbate (990 mg, 5 mmol) under air. After that, 60 mL of 3:2: 1 (v / v) THF, MeCN and H2O were added to the mixture and allowed to heat at 80 °C for 4 days. After, completion of the reaction, an excess of cone. Aq. NH4OH was added to quench the reaction and the resulting mixture was further stirred for 30 min. Then, the mixture was evaporated under reduced pressure, diluted and extracted with CH2CI2 and the combined organic fractions were dried over anhydrous Na2SO4 and subjected to the flash silica gel column chromatography to yield triazole as a white solid (4.26 g, 70%). (500 MHz, 1H NMR CDCh) δ 7.27 - 7.24 (m, 4H), 7.21 - 7.16 (m, 6H), 7.12 (t, J = 7.2 Hz, 2H), 7.04 (d, J = 7.3 Hz, 4H), 6.88 (d, J = 7.4 Hz, 4H), 6.83 - 6.81 (m, 4H), 6.46 (s, 1H), 5.15 (s, 2H), 2.24 (s, 6H), 1.85 (s, 6H).13C NMR (126 MHZ, ) δ 1C44D.6C,I3143.5, 142.7, 141.2. 140.2, 138.2.

[0274] 138.1, 133.3. 130.1, 129.9. 129.1, 128.5, 128.5, 128.2, 126.9. 126.8, 126.8. 126.7, 51.0, 22.0, 21.2, 20.9. HRMS (APCI): calcd for C44H40N3 [M + H]+ 610.3217, found 610.3220. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-mesityl-3-methyl-lH-l,2,3-triazol-3-ium iodide, MIC-Ipr* / MesMe,HI. In an oven-dried 100 mL round-bottomed flask, triazole (3.05 g, 5 mmol) was taken and dissolved in 15 ml of CH3CN. Methylating agent CH3I (10 equivalent) was added to the mixture and allowed to stir at 70 °C for 2 days. After the completion of the reaction, the solvent was evaporated and washed with diethyl ether 3-4 times to give the pure product (yield = 95%, 3.57 g). (500 MHz1H, C NDMCRls) δ 8.35 (s, 1H), 7.24 (t, J = 26.4 Hz, 12H), 7. 10 (d, J = 7.4 Hz, 4H), 7.00 (d, J = 7.2 Hz, 4H), 6.93 (s, 2H), 6.80 (s, 2H), 5.40 (s, 2H), 3.86 (s, 3H). 2.29 (s, 3H), 2.24 (s. 3H), 1.95 (s, 6H).13C NMR (126 MHz, CDC)I3 δ 142.8, 142.6, 141.7, 141.5, 141.4, 140.8, 138.1, 132.8, 131.0, 130.9, 129.6, 129.4, 129.4, 128.8, 128.5, 127.3, 127.1, 116.8, 51.1, 39.3, 22.0, 21.3, 21.2. HRMS (APCI): calcd for C45H42N3 [M]~ 624.3373, found 624.3315. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-mesityl-3-methyl-lH-l,2,3-triazol-3-ium tetrafluoroborate, MIC-Ipr* / MesMe-HBF4. In an oven-dried 25 mL round-bottomed flask, triazole (1.2 g, 2.0 mmol) was taken and dissolved in 6 ml of dry CH3CN. Methylating agent Me.3OBF4 (10.0 equiv.) was added to the mixture and allowed to stir at room temperature for 48 h. After the completion of the reaction, the solvent was evaporated, and the residue was dissolved into 10 mL of DCM, followed by the addition of 2 mL of H2O. After the workup, the mixture dried over Na2SO4, evaporated to dryness and washed with diethyl ether 2-3 times to give the pure product (yield = 88%, 1.25 g). (500 MHz1H, C NDMCRls) δ 7.58 (s, 1H), 7.30 - 7.27 (m, 5H), 7.26 - 7.23 (m, 4H), 7.21 - 7.18 (m, 3H), 7.01 - 6.98 (m, 8H), 6.94 (s, 2H), 6.82 (s, 2H), 5.25 (s. 2H), 3.83 (s, 3H), 2.30 (s, 3H), 2.26 (s, 3H), 1.89 (s, 6H).13C NMR (126 MHz, CDCI3) δ 143.0. 142.7, 141.9. 141.8, 141.7. 140.9, 138.4. 132.4, 131.1, 131.0, 129.7, 129.4, 129.4, 129.0, 128.7, 127.4, 127.2, 117.0, 51.2, 38.1, 22.2, 21.4, 20.4. HRMS (APCI): calcd for C45H42N3 [M]+624.3373, found 624.3364. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-(2,6-diisopropylphenyl)-lH-l,2,3- triazole. An oven-dried 100 mL round-bottomed flask equipped with a stir bar was charged with the corresponding azide (4.66 g, 10 mmol), 2-ethynyl-1.3-diisopropylbenzene (2. 15 g, 15 mmol), CuSO4 (319 mg, 2.0 mmol) and sodium ascorbate (990 mg, 5 mmol) under air. After that, 60 mL of 3 :2: 1 (v / v) THF, MeCN and H2O were added to the mixture and allowed to heat at 80 °C for 4 days. After, completion of the reaction, an excess of cone. aq. NH4OH was added to quench the reaction and the resulting mixture was further stirred for 30 min. Then, the mixture was evaporated under reduced pressure, diluted and extracted with CH2CI2 and the combined organic fractions were dried over anhydrous Na2SO4, and washed with hexanes 3-4 times to yield triazole as a white solid (4.8 g, 74%). (500 MHz, 1H N)MR CDCI3 5 7.34 - 7.31 (m. 1H), 7.30 - 7.27 (m, 4H), 7.25 - 7.22 (m, 6H), 7.19 - 7.14 (m, 4H), 7.08 (d, J = 7.3 Hz. 4H), 6.94 (d. J = 7.4 Hz, 4H), 6.90 (s, 2H), 6.72 (s, 1H). 5. 13 (s, 2H). 2.48 - 2.40 (m, 2H), 2.28 (s, 3H), 1 .03 (d, J = 6.9 Hz, 12H).13C NMR (126 MHz, CDCls) δ 148.8, 144.2,

[0275] 143.6, 142.7, 141.1, 140.3, 133.2, 130.1, 129.8, 129.3, 129.0, 128.6, 128.5, 127.7, 126.8,

[0276] 126.7, 126.3, 122.6, 51.0, 30.6, 24.2, 22.0. HRMS (APCI): calcd for C47H46N3 [M + H]+ 652.3686, found 652.3689. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-(2,6-diisopropylphenyl)-3-methyl-lH- 1 ,2,3-triazoI-3-ium iodide, MIC-IPr* / DippMe,HI. In an oven-dried 100 mL round- bottomed flask, triazole (3.26 g, 5 mmol) was taken and dissolved in 15 ml of CHsCN. Methylating agent CH3I (10 equivalent) was added to the mixture and allowed to stir at 70 °C for 2 days. After the completion of the reaction, the solvent was evaporated and washed with diethyl ether for 3-4 times to give the pure product (yield = 90%, 3.57 g). (500 1H NMR MHz, CDCI3) δ 10.09 (s, 1H), 7.55 (t, J = 7.9 Hz, 1H), 7.31 - 7.18 (m, 18H), 6.94 (d, J = 7.0 Hz, 4H), 6.79 (s, 2H), 5.30 (s, 2H), 3.42 (s, 3H), 2.24 (s, 3H), 2.21 - 2.11 (m, 2H), 2.20 - 2.17 (m, 12H).13C NMR (126 MHz, ) δ C 14D9C.0I3, 142.9, 142.1, 141.2, 140.8. 140.7, 134.0, 133.3. 131.1, 131.0. 129.9, 129.3, 128.9. 128.5, 127.3. 127.1, 124.4. 117.3, 51.6, 37.8, 31.9, 25.4, 23.6, 22.2. HRMS (APCI): calcd for C48H48N3 [M - 1]+ 666.3843, found 666.3850. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-(2,6-diisopropylphenyl)-3-methyl-lH- l,2,3-triazol-3-ium tetrafluoroborate, MIC-IPr* / DippMe,HBF4. In an oven-dried 25 mL round bottomed flask, triazole (1.3 g, 2.0 mmol) was taken and dissolved in 6 ml of dry CH3CN. Methylating agent MesOBF4 (10.0 equiv.) was added to the mixture and allowed to stir at room temperature for 48 h. After the completion of the reaction, the solvent was evaporated, and the residue was dissolved into 10 mL of DCM, followed by the addition of 2 mL of H2O. After the workup, the mixture dried overNa2SO4,, evaporated to dryness and washed with diethyl ether 2-3 times to give the pure product (yield = 84%, 1.27 g). 'H NMR (500 MHz, CDC)I3 δ 8.95 (s, 1H), 7.55 (t, J = 7.9 Hz, 1H), 7.31 - 7.28 (m, 7H), 7.24 - 7.21 (m, 5H), 7.09 (d, J = 7.5 Hz, 4H), 6.92 (d, J = 7.2 Hz, 4H), 6.80 (s, 2H), 5.19 (s, 2H), 3.37 (s, 3H), 2.24 (s, 3H), 2.18 - 7.22 (m, 2H), 1.20 (d, J = 6.8 Hz, 6H), 1.14 (d, J = 6.7 Hz, 6H).13C NMR (126 MHz, CDC)I δ3 148.98, 148.97, 142.8, 142.0, 142.0, 141.3, 141.2, 140.6, 133.1, 131.0, 130.8. 129.6, 129.2, 128.8, 128.5, 127.2, 127.0, 127.0, 124.2, 117.2. 51.6, 37.2, 31.7, 24.8, 23.3, 22.0. HRMS (APCI): calcd for C48H48N3 [M - BF4]+ 666.3843, found 666.3831. l-(2,6-Dibenzhydryl-4-methylphenyl)-3-phenyltriaz- 1-ene. In a dry oven-dried round botom flask, iodobenzene (0.6 g, 3 mmol) in THF (10 mL) was added and cooled to - 78 °C. Then, a hexane solution of n-butyllithium (2 mL, 3.2 mmol, 1.6 M) was added to a solution at -78 °C and stirred for 30 minutes. After that. ((2-azido-5-methyl-l,3- phenylene)bis(methanetriyl))tetrabenzene (1.4 g, 3 mmol) was dissolved in 10 mL of THF and added dropwise over 30 min afforded a clear orange reaction mixture that was warmed to room temperature over 18 h. The dark reaction mixture, water (10 mL) was added dropwise followed by the saturated aqueous solution of NH4CI. The organic solution was extracted with diethyl ether (3 x 15 mL), dried (anhydrous MgSCL). filtered and concentrated under a rotary evaporator. The mixture was then subjected to the flash silica gel column chromatography to give triazene (1.14 g, 2.1 mmol, 70%) as the product. (500 1H NMR MHz, CDCI3) 6 8.95 (brs, 1H), 7.32 (t, J = 7.3 Hz, 2H), 7.29 - 7.26 (m. 9H), 7.22 - 7.19 (m, 4H), 7.13 (d. J = 7.4 Hz. 2H), 7.08 (d. J = 7.5 Hz. 8H), 6.72 (s, 2H), 5.77 (s, 2H). 2.20 (s, 3H).13C NMR (126 MHZ, )C δDC 14I33.68, 143.19, 129.74, 129.61, 129.59, 129.03, 128.70, 128.51, 128.40, 127.98, 126.65, 126.35, 77.41, 77.16, 76.91, 52.00, 21.71. l,4-bis(2,6-Dibenzhydryl-4-methylphenyl)-3-phenyl-lH-l,2,3-triazol-3-ium hexafluorophosphate, MIC-IPr* / IPr*pl’-HPF4. An oven-dried reaction tube equipped with a stir bar was charged with the corresponding triazene (2 mmol) and potassium hexafluorophosphate (3 mmol, 0.55 g) and dry dichloromethane solution (10 mL) was then added to it. The mixture was then cooled to -78 °C and tert-butyl hypochlorite (3 mmol) in THF solution (5 mL) was added dropwise. After 30 minutes of stirring, aryl alkyne (3.0 mmol) was added and stirred at - 78°C for 6 hours then allowed to come at room temperature and stirred additionally for 6 h. After completion of the reaction, di chloromethane (10 mL) was added to the mixture. The resulting mixture was filtered through a pad of Celite, and the pad was rinsed with dichloromethane. The filtrate was concentrated in vacuo. The crude product was washed with diethyl ether for 5-6 times to give pure salt. (Yield = 72%). ’H NMR (500 MHz, CDCL) δ 8.77 (s, 1H). 7.34 (d, J = 7.3 Hz, 1H). 7.24 - 7.19 (m, 7H). 7.16 - 7.18 (m, 15H), 6.99 - 6.95 (m, 3H), 6.91 - 6.90 (m, 10H), 6.84 (d, J = 7.1 Hz, 4H), 6.79 (s, 2H), 6.59 (d, J = 7.2 Hz, 4H), 5.99 (d, J = 8.5 Hz, 2H), 4.93 (s, 2H), 4.88 (s, 2H), 2.24 (s, 6H).13C NMR (126 MHz, CDCL) δ 144.0, 143.4, 143.3, 142.0, 141.9, 141.0, 140.6, 140.4, 140.3, 133.4. 131.8, 131.1, 130.9, 130.7, 129.7, 129.6, 129.4, 129.2, 129.1, 128.8, 128.7. 128.7, 128.7, 127.5, 127.5, 127.3, 127.1, 127.0, 127.0, 122.8, 54.0, 51.6, 22.0, 22.0. HRMS (APCI): calcd for C74H60N3 [M+- BF4’] 990.4782, found 990.4898.

[0277] 4-(2,6-Dibenzhydryl-4-methylphenyl)-l,3-bis(2,6-diisopropylphenyl)-lH-l,23- triazol-3-ium hexafluorophosphate, MIC-Dipp / IPr*Dipp-HPF6. An oven-dried reaction tube equipped with a stir bar was charged with the corresponding triazene (2 mmol) and potassium hexafluorophosphate (3 mmol, 0.55 g) and diy dichloromethane solution (10 mL) was then added to it. The mixture was then cooled to -78 °C and tert-butyl hy pochlorite (3 mmol) in THF solution (5 mL) was added dropwise. After 30 minutes of stirring, aryl alkyne (3.0 mmol) was added and stirred at - 78°C for 6 hours then allowed to come at room temperature and stirred additionally for 6 h. After completion of the reaction, di chloromethane (10 mL) was added to the mixture. The resulting mixture was filtered through a pad of Celite, and the pad was rinsed with dichloromethane. The filtrate was concentrated in vacuo. The crude product was washed with diethyl ether for 5-6 times to give pure salt. (Yield = 58%). 1H (5 N0M0 R MHz. ) 6 7.C89D (Ct,I3 J = 7.9 Hz, 1H), 7.73 (t, J = 7.9 Hz, 1H), 7.54 (d, J = 7.9 Hz, 2H), 7.41 (d, J = 7.9 Hz, 2H), 7.33 - 7.31 (m, 5H), 7.25 - 7.24 (m, 6H), 6.88 (brs, 2H), 6.70 - 7.65 (m, 4H), 6.56 - 7.34 (m, 3H), 6.19 (s, 1H), 5.01 (s, 2H), 2.48 - 2.39 (m, 2H), 2.26 (s, 3H), 1.89 - 1.82 (m, 2H), 1.27 (d, J = 6.7 Hz, 6H), 1.22 (d, J = 6.8 Hz, 6H), 1.09 - 1.02 (m, 6H), 0.95 - 0.88 (m, 6H).13C NMR (126 MHz, ) 5 CDCI3 145.3, 144.9. 144.3, 143.93, 142.8, 140.9. 134.2, 134.1. 132.9, 130.7. 129.6, 129.5, 129.3,

[0278] 129.2, 129.0, 128.5, 127.9, 127.8, 126.9, 125.6, 117.8, 54.4, 30.5, 29.6, 26.7, 24.6, 23.9, 22.2. HRMS (APCI): calcd for C59H62N3 [M+- PF6-] 812.4938, found 812.4916.

[0279] Synthesis via Direct N-alkylation with Sterically-Hindered Alkyl Halides. MIC- IPr* / MesiPr HI. l-(2,6-Dibenzhydryl-4-methylphenyl)-3-isopropyl-4-inesityl-lH-l,2,3-triazol-3- ium iodide, MIC-IPr* / MeslPl ,HI. In an oven-dried 100 mL round-bottomed flask, triazole (609.8 mg, 1 mmol) was taken and dissolved in 6 ml of CH3CN. Methylating agent CH3I (10 equiv) was added to the mixture and allowed to stir at 70 °C for 2 days. After the completion of the reaction, the solvent was evaporated and washed with diethyl ether 3-4 times to give the pure product triazole-iodo salt (yield = 86%, 0.67 g). H NMR (500 MHz, ) δ 9.38 CDCI3 (s, 1H), 7.31 - 7.23 (m, 12H), 7.10 - 7.09 (m, 4H), 7.02 (s, 2H), 6.95 (d, J = 7.0 Hz, 4H), 6.81 (s, 2H), 5.28 (s, 2H), 4.23 - 4.21 (m, 1H), 2.33 (s, 3H), 2.26 (s, 3H), 1.94 (s, 6H), 1.02 (d, J = 5.8 Hz, 6H).13C NMR (126 MHZ, ) 143C.2D, C 14I32.9, 141.8, 141.2, 140.8, 140.1. 137.7, 133.7. 131.4, 131.2. 129.9. 129.8, 129.3. 129.1, 128.8. 127.5, 127.4. 116.9, 55.8, 51.6,

[0280] 22.2, 22.0, 21.5, 21.0. HRMS (APCI): calcd for C47H46N3 [M+- 1-] 652.3686, found 652.3672.

[0281] Synthesis via Cu-Catalyzed Oxidative N-Arylation with Aryl lodonium Salts, MIC- IPr* / MesPhHBF4. l-(2,6-Dibenzhydryl-4-methylphenyl)-4-mesityl-3-phenyl-lH-l,2,3-triazol-3-ium tetrafluoroborate, MIC-IPr* / Mespll-HBF4. An oven-dried reaction tube equipped with a stir bar was charged with triazole (0.2 mmol, 1 equiv), diary liodonium salt (Ph2l+BF4-) (0.36 mmol, 1.8 equiv), and anhydrous CuSOr (6.3 mg, 0.04 mmol, 20 mol %). The reaction mixture was flushed with nitrogen gas, dry DMF (2 mL) was added to it and stirred for 16 h at 130 °C. The reaction was then cooled down and the crude mixture was then subjected to the flash silica gel column chromatography (MeOH / di chloromethane = 1:30 to 1 : 10. v / v) to give white solid salt (60 mg, 40%). (510H0 N MMHRz, ) δ 9.68 (Cs,D 1CHI)3, 7.45 (t, J = 7.5 Hz, 1H), 7.32 - 7.27 (m, 6H), 7.23 - 7.17 (m, 6H), 7.14 (d, J = 7.2 Hz, 2H), 7.10 - 7.09 (m, 4H), 6.94 (d, J = 7.3Hz, 4H), 6.87 (s, 2H), 6.79 (s, 2H), 6.48 (d. J = 7.9 Hz. 2H), 5.41 (s, 2H), 2.26 (s, 3H), 2.24 (s, 3H), 1.83 (s, 6H).13C NMR (126 MHz, ) δ 143.0. 14C2.D6,CI3 142.2, 141.3, 141.1, 140.5, 137.8, 135.1, 133.9, 131.9, 131.5, 131.2, 129.8, 129.8, 129.6, 129.5, 129.0, 128.7, 127.4, 127.0, 123.3, 117.8, 51.8, 22.1, 21.4, 20.5. HRMS (APCI): calcd for C50H44N3 [M+- PF6-] 886.3530, found 886.3515.

[0282] Example 2: Synthesis of MIC-IPr*-Metal Complexes

[0283] (3,5-bis(2,6-Dibenzhydryl-4-methylphenyl)-l-methyl-2,3-dihydro-l / 7-l,2,3- triazol-4-yl)gold(I) iodide, [Au(MIC-IPr* / IPr*Me)I], An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / IPr*Me HI (105.6 mg, 0. 10 mmol, 1.0 equiv) and KOtBu (22.4 mg. 2.0 equiv) under the argon atmosphere. Dry and degassed THF (1 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Au(Me2S)Cl] (29.5 mg, 0.1 mmol, 1.0 equiv) in dry THF (0.5 mL) was added and the reaction mixture was stirred at room temperature for 12 h. The reaction mixture was filtered through celite using 5 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from diethyl ether / hexanes (1 : 10 v / vol) as a white solid (114 mg. yield = 91%). 1H NM (5R00 MHz, ) C δ D 7.C36I3 - 7.28 (m, 14H), 7.24 - 7.22 (m, 14H), 7.15 (d, J = 7.4 Hz, 4H), 7.11 - 7.09 (m, 4H), 7.08 (s, 2H), 7.01 (d, J = 6.7 Hz, 4H), 6.94 (s, 2H), 5.36 - 5.35 (m, 4H), 2.37 (s, 3H), 2.33 (s, 3H), 2.18 (s, 3H).1?C NMR (126 MHz, CDCh) 6 174.5, 145.2, 144.5, 143.0, 142.7, 141.6, 141.6, 141.1, 141.0, 140.1, 134.8. 130.5, 129.7, 129.7. 129.5, 129.4, 128.9, 128.8, 128.4, 128.4, 126.9. 126.8, 126.6. 126.5, 122.5. 54.0, 51.0, 35.7, 22.0. HRMS calcd for C69H57AUN3 [M - I]+ 1124.4213, found 1124.4221.

[0284] (3,5-bis(2,6-Dibenzhydryl-4-methylphenyl)-l-methyl-2,3-dihydro-l / / -l,2,3- triazol-4-yl)gold(I) chloride, [Au(MIC-IPr* / IPr*Me)ClJ. An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / IPr*Me HBF4 (101.6 mg, 0.10 mmol, 1.0 equiv) and KOtBu (22.4 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (1 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Au(Me2S)Cl] (29.5 mg, 0.1 mmol, 1.0 equiv) in dry THF (0.5 mL) was added and the reaction mixture was stirred at room temperature for 12 h. The reaction mixture was filtered through celite using 5 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from diethyl ether / hexanes (1 :10 v / vol) as a white solid (104 mg, yield = 90%). ‘HNMR (500 MHz, )C 6D 7C.2I34 - 7.09 (m, 28H), 7.01 - 6.97 (m. 10H), 6.89 - 6.88 (m. 4H), 6.81 (s. 2H), 5.21 (s, 4H), 2.26 (s, 3H), 2.22 (s, 3H). 2.00 (s, 3H).13C NMR (126 MHz, CDC)I δ3 164.7, 145.3, 144.9, 143.3, 142.7, 141.8, 141.6, 141.3, 141.1, 140.1, 135.0, 130.6, 129.83, 129.75, 129.6, 129.5, 128.86, 128.85, 128.52, 128.45, 126.99, 126.96. 126.69, 126.66, 122.6, 54.1, 51.1, 35.8, 22.1. HRMS calcd for C69H57AUN3 [M - Cl]+ 1124.4213, found 1124.4249.

[0285] [Au(MIC-IPr* / PhMe)I] . An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / PhMe HI (142.0 mg, 0.20 mmol, 1.0 equiv) and KOtBu (44.8 mg. 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Au(Me2S)Cl] (59.0 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 6 h. The reaction mixture was filtered through celite using 10 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from DCM / hexanes (1: 10 v / vol) to give white solid Au-complex. Yield = (114 mg, 63%). 'H NMR (500 MHz, CDC)I3 δ 7.51 (s, 5H), 7.29 - 7.26 (m, 4H), 7.24 - 7.17 (m, 8H), 7.11 (d, J = 7.3 Hz. 4H), 6.95 (d, J = 6.9 Hz, 4H), 6.70 (s, 2H), 5.72 (s, 2H), 3.53 (s, 3H). 2.22 (s, 3H).13C NMR (126 MHz, CDC)I δ3 171.6. 145.5, 142.0. 141.3, 141.1. 140.7, 135.1, 130.4, 130.1, 129.7, 129.4, 129.3, 128.9, 128.3, 126.9, 126.54, 126.3, 52.2, 37.3, 22.1. HRMS (APCI): calcd for C42H35N3 [M - 1]+ 778.2491, found 778.2510.

[0286] [Au(MIC-IPr* / MesMe)IJ. An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / MesMe HI (150.3 mg, 0.20 mmol, 1.0 equiv) and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Au(Me2S)Cl] (59.0 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 6 h. The reaction mixture was filtered through celite using 10 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from DCM / hexanes (1: 10 v / vol) as a white solid. Yield = (176.5 mg, 84%). 'l l NMR (500 MHz, CDCh) 6 7.28 (d, J = 7.3 Hz, 3H). 7.21 (d, J = 14.0 Hz, 6H), 7. 17 (d, J = 7.0 Hz, 2H), 7. 14 (d, J = 7.4 Hz, 4H), 6.94 (s, 2H), 6.92 (d, J = 7.0 Hz, 4H), 6.73 (s, 2H), 5.48 (s, 2H), 3.22 (s, 3H), 2.32 (s, 3H), 2.24 (s, 3H), 2.05 (s, 6H).13C NMR (126 MHz, ) δ 172.9, 1C44D.3C,I3142.5, 141.9, 140.9, 140.8, 140.7, 138.0, 135.5, 130.5, 129.9, 129.4, 129.2, 128.8, 128.3, 126.9, 126.6, 122.2, 51.4, 36.0, 22.1, 21.4, 20.8. HRMS (APCI): calcd for C45H41A11N3 [M - Cl]+ 820.2961, found 820.2954.

[0287] [Au(MIC-IPr* / MesMe)Cl], An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / MesMe HBF4 (142.3 mg, 0.20 mmol, 1.0 equiv) and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Au(Me2S)Cl] (59.0 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 6 h. The reaction mixture was filtered through celite using 10 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from DCM / hexanes (1: 10 v / vol) as a white solid. Yield = (104.3 mg, 61%). (500 MHz. 1H NMR CDCh) δ 7.29 - 7.26 (m, 4H). 7.22 - 7.16 (m. 8H), 7.13 (d. J = 7.3 Hz. 4H), 6.94 (s. 2H), 6.91 (d, J = 6.9 Hz, 4H), 6.73 (s, 2H), 5.46 (s, 2H), 3.18 (s, 3H), 2.32 (s, 3H), 2.23 (s, 3H), 2.05 (s, 6H).13C NMR (126 MHz, ) δC 1D62C.I23, 144.8, 142.5, 141.9, 140.9, 140.8, 140.7, 138.0, 135.5, 130.5, 129.9. 129.4, 129.1, 128.7, 128.3, 126.9, 126.6, 122.2, 51.6, 36.0, 22.0, 21.4, 20.8. HRMS (APCI): calcd for C45H41AUN3 [M - Cl]+ 820.2961, found 820.2972.

[0288] [Au(MIC-IPr* / DippMe)I], An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / DippMe HI (158.8 mg, 0.20 mmol, 1.0 equiv) and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Au(Me2S)Cl] (59.0 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 8 h. The reaction mixture was filtered through celite using 10 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from DCM / hexanes (1: 10 v / vol) as a white solid. Yield = (176.5 mg, 88%). (500 MHz, 1H NMR CDCh) δ 7.50 (t, J = 7.8 Hz, 1H), 7.30 - 7.27 (m, 6H), 7.23 - 7.20 (m, 6H), 7.18 - 7.16 (m, 6H), 6.92 (d, J = 7.2 Hz, 4H), 6.74 (s, 2H), 5.46 (s, 2H). 3.12 (s, 3H), 2.41 - 7.36 (m, 2H), 2.24 (s. 3H), 1.29 (d. J = 6.8 Hz. 6H), 1.16 (d. J = 6.9 Hz. 6H).13C NMR (126 MHz. ) CDCI3 5 173.2, 149.0, 143.7, 142.6, 142.1, 140.9, 140.5, 135.3, 131.7, 130.5, 129.9, 129.3, 128.8, 128.2, 126.9, 126.5, 123.9, 122.3, 51.5, 36.1, 31.5, 25.4, 23.4, 22.1. HRMS (APCI): calcd for C48H47AUN3 [M - 1]+ 862.3430, found 862.3455.

[0289] [Au(MIC-IPr* / DippMe)Cl] . An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / DippMe HBF4 (153.6 mg, 0.20 mmol, 1.0 equiv) and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Au(Me2S)Cl] (59.0 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 8 h. The reaction mixture was filtered through celite using 10 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from DCM / hexanes (1: 10 v / vol) as a white solid. Yield = (153.0 mg, 84%). 'H NMR (500 MHz, CDC)I δ37.50 (t, J = 7.8 Hz, 1H), 7.31 - 7.25 (m, 6H), 7.24 - 7.19 (m, 6H), 7.18 - 7.14 (m, 6H), 6.91 (d, J = 7.2 Hz, 4H), 6.74 (s, 2H), 5.44 (s, 2H), 3.08 (s, 3H), 2.43 - 2.33 (m, 2H), 2.24 (s, 3H), 1.32 (d, J = 6.8 Hz, 6H), 1.17 (d, J = 6.9 Hz, 6H).1?C NMR (126 MHz, CDCI3) δ 162.7, 149.1, 144.3. 142.7, 142.1. 141.0, 140.6, 135.4, 131.8, 130.5, 129.9, 129.3, 128.8. 128.2, 127.0. 126.5, 123.9, 122.4. 51.7. 36.1, 31.5, 25.4, 23.5, 22.1. HRMS (APCI): calcd for C48H47AUN3 [M - Cl]+ 862.3430, found 862.3448.

[0290] [Se(MIC-IPr* / IPr*Me)]. An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / IPr*Me HI (105.6 mg, 0.10 mmol, 1.0 equiv), selenium (24 mg, 0.30 mmol, 3.0 equiv) and KOtBu (22.4 mg, 2.0 equiv) under the argon atmosphere. To this mixture, dry THF was added at room temperature and stirred for 12 h. The reaction mixture was filtered through celite using 5 mL of DCM. The solution was then concentrated under the reduced pressure and washed with hexanes. The product was obtained as a yellow solid (93.4 mg, yield = 93%). 1H NMR (500 MHz, ) δ 7C.5D2C (Id3, J = 7.5 Hz, 4H), 7.38 (d. J = 7.5 Hz. 4H), 7.25 -7.20 (m, 8H). 7.16 - 7.14 (m, 10H), 7.08 - 7.05 (m, 2H), 7.02 (t, J = 7.3 Hz, 4H), 6.98 (s, 2H), 6.93 - 6.91 (m, 4H), 6.88 (s, 2H), 6.80 (d, J = 7.2 Hz, 4H), 5.39 (s, 2H), 5.29 (s, 2H), 2.25 (s, 6H), 1.75 (s, 3H).13C NMR (126 MHz, ) δ 153.3, 1C45D.C8,I3143.4, 143.0, 142.2, 141.1, 140.8, 140.8, 140.6, 132.8, 130.7, 130.6, 130.0, 129.9, 129.7, 129.5, 128.6, 128.3. 128.2, 126.7, 126.6, 126.4, 126.3, 122.9, 54.5, 51.8, 36.2. 22.14, 22.06.77Se NMR (95 MHz, CDC)I3 δ (ppm) 66.01 (s, CSe). HRMS (APCI): calcd for CegHssNsSe |M + H]+ 1008.3801, found 1008.3800.

[0291] [(MIC-IPr* / PhMe)Se], An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / PhMe HI 1 (71.0 mg, 0.10 mmol, 1.0 equiv), selenium (24 mg, 0.30 mmol, 3.0 equiv) and KOtBu (22.4 mg, 2.0 equiv) under the argon atmosphere. To this mixture, dry THF was added at room temperature and stirred for 12 h. The reaction mixture was filtered through celite using 10 mL of THF. The solution was then concentrated under the reduced pressure and washed with hexanes. The product was obtained as a yellow solid (54.8 mg, yield = 83%). 1H NMR (500 MHz, ) δ 7.7C1D (Cd,I3 J = 7.8 Hz, 2H), 7.55 (t, J = 7.5 Hz. 2H), 7.49 (t, J = 7.4 Hz, 1H), 7.27 - 7.23 (m, 8H), 7.19 - 7.11 (m, 8H). 6.94 (d, J = 7.3 Hz, 4H), 6.73 (s, 2H), 5.56 (s, 2H), 3.21 (s, 3H), 2.21 (s, 3H).13C NMR (126 MHz, CDCh) δ 148.2, 142.3, 142.1, 142.0, 140.2, 140.1, 132.6, 130.0, 129.9, 129.8, 129.1. 129.0, 128.3, 127.9. 126.5, 126.3, 126.1, 52.3, 37.4, 21.9. HRMS (APCI): calcd for C'42H:.5N3Se [M + H]+ 662.2073, found 662.2053.77Se NMR (76 MHz, ): 8 (ppm) 9C.D 19C (Is3, CSe).

[0292] [(MIC-IPr* / MesMe)Se], An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / MesMe HI (75.2 mg, 0.10 mmol, 1.0 equiv), selenium (24 mg, 0.30 mmol, 3.0 equiv) and KOtBu (22.4 mg, 2.0 equiv) under the argon atmosphere. To this mixture, dry THF was added at room temperature and stirred for 12 h. The reaction mixture was fdtered through celite using 10 mL of THF. The solution was then concentrated under the reduced pressure and washed with hexanes. The product was obtained as a yellow solid (61.7 mg, yield = 88%). 1H NMR (500 MHz, ) 8 7.2C8D -C 7I3.27 (m, 5H), 7.25 - 7.24 (m, 3H), 7.21 - 7.11 (m, 8H), 7.00 (s, 2H), 6.91 (d, J = 7.1 Hz, 4H), 6.74 (s, 2H), 5.39 (s. 2H), 2.99 (s. 3H), 2.33 (s. 3H), 2.22 (s, 3H), 2.18 (s, 6H).13C NMR (126 MHz, ) 8 142.7. CDCI3 142.4, 141.8, 141.2, 140.8, 140.4, 138.5, 132.7, 130.2, 130.2, 129.4, 129.1, 128.4, 128.0, 126.7, 126.3, 52.3, 36.2, 22.1, 21.44, 20.39. HRMS (APCI): calcd for C45H42N3Se [M + H]+ 704.2543, found 704.2527.77Se NMR (76 MHz, ): 8 (ppmC)D 0C.0I53 (s, CSe).

[0293] [(MIC-IPr* / DippMe)Se]. An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / DippMe HI (79.4 mg, 0.10 mmol, 1.0 equiv), selenium (24 mg, 0.30 mmol, 3.0 equiv) and KOtBu (22.4 mg, 2.0 equiv) under the argon atmosphere. To this mixture, dry THF was added at room temperature and stirred for 12 h. The reaction mixture was fdtered through celite using 10 mL of THF. The solution was then concentrated under the reduced pressure and washed with hexanes. The product was obtained as a yellow solid (67 mg, yield = 90%). 1H NMR (500 MHz, ) 8 7.C50DC (t,I3 J = 7.8 Hz, 1H), 7.30 - 7.24 (m, 10H), 7.21 - 7.16 (m, 6H), 7.14 - 7.11 (m, 2H), 6.92 (d, J = 7.4 Hz, 4H), 6.74 (s, 2H), 5.40 (s, 2H). 2.92 (s, 3H), 2.55 - 2.50 (m. 2H), 2.22 (s, 3H), 1.42 (d, J = 6.7 Hz, 6H), 1.16 (d, J = 6.9 Hz. 6H).13C NMR (126 MHz. ) 8C 1D5C1I.30, 149.6, 142.9, 142.7, 141.6, 140.4, 140.3. 132.8, 131.5, 130.2, 130.2, 129.3, 128.4, 128.0, 126.7, 126.2, 123.8, 122.9, 52.3, 36.4, 32.0, 25.3, 24.0, 22.1. HRMS (APCI): calcd for C4sH48N3Se [M + H]+ 746.3013, found 746.3032.77Se NMR (76 MHz, C)D: C 5I (3ppm) 29.42 (s, CSe).

[0294] General Procedure for the Synthesis of NHC-Ag Complexes

[0295] An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* HI or MIC-IPr* HPFe (0.20 mmol, 1.0 equiv) and Ag2O (50.8 mg, 1.1 equiv) under the argon atmosphere. Dry and degassed DCM (2 mL) was added to the mixture and stirred at room temperature for 8 h. The reaction mixture was filtered through celite using 10 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from DCM / hexanes (1: 10 v / vol) as a white solid.

[0296] [Ag(MIC-IPr* / PhMe)I] . Yield = 92%. 1H (5 N0M0 MRHz, ) δ 7.5C0D -C 7I3.49 (m, 3H), 7.34 - 7.32 (m, 2H), 7.29 (t, J = 7.4 Hz, 4H). 7.24 - 7.19 (m, 8H). 7.02 (d, J = 7.3 Hz, 4H), 6.94 (d, J = 6.9 Hz, 4H), 6.69 (s, 2H), 5.52 (s, 2H), 3.62 (s, 3H), 2.23 (s, 3H).13C NMR (126 MHz, CDC)I3 δ 169.7 (dd, J = 239.8, 17.0 Hz) (Ctrz-Ag), 147.6 (d, J = 16.6 Hz) (Ctrz),

[0297] 142.0, 141.3, 141.0, 140.5, 135.9, 130.3, 130.0, 129.6, 129.39, 129.37, 129.36, 129.0, 128.4,

[0298] 127.14. 127.08, 76.9, 52.4, 36.8. 22.0. HRMS (APCI): calcd for C42H35AgN3[M - 1]+ 688.1876, found 688.1870.

[0299] [Ag(MIC-IPr* / MesMe)I] . Yield = 95%. 1H (5 N00M MRHz, ) 8 7.3C1 D -C 7I.328

[0300] (m, 4H), 7.24 - 7.17 (m, 8H), 7.06 - 7.04 (m, 4H), 6.93 - 6.92 (m, 4H), 6.91 (s, 2H), 6.76 (s, 2H), 5.30 (s, 2H), 3.36 (s, 3H), 2.31 (s, 3H), 2.25 (s, 3H), 1.96 (s, 6H).1?C NMR (126 MHz, CDCh) δ 146.5 (d. J = 16.4 Hz) (Ctrz), 146.4. 142.7, 141.6. 140.7, 140.5, 137.9, 136.2, 130.5, 129.7, 129.4, 129.1, 129.0, 128.3, 127.1, 126.6, 122.8, 51.5, 35.7, 22.0, 21.3, 20.8. HRMS (APCI): calcd for C45H4iAgN3 [M - 1]+ 730.2345, found 730.2330.

[0301] [Ag(MIC-IPr* / DippMe)I] Yield = 98%. 'l l NMR (500 MHz, ) δ 7.C50D (Ct,I3 J = 7.8 Hz. 1H), 7.34 - 7.31 (m, 4H), 7.28 - 7.20 (m, 10H). 7.11 (d, J = 7.5 Hz, 4H). 6.94 (d, J = 7.2 Hz, 4H), 6.80 (s, 2H), 5.32 (s, 2H), 3.29 (s, 3H), 2.39 - 2.31 (m, 2H), 2.27 (s, 3H), 1.19 - 1.16 (m, 12H).13C NMR (126 MHz, ) δ C 17D4C.7I3 (dd, J = 222.3, 16.2 Hz) (Ctrz-Ag), 148.9, 145.8 (d, J = 15.7 Hz) (Ctrz), 142.8, 141.8, 140.9, 140.3, 135.9, 131.6, 130.5, 129.6, 129.3, 129.0, 128.3, 127.0. 126.6, 123.8, 122.8, 51.4, 35.9, 31.3, 25.4, 23.4, 22.1. HRMS (APCI): calcd for C48H47AgN?[M - 1]+ 772.2815. found 772.2835.

[0302] [Ag(MIC-IPr* / IPr*Me)I], Yield = 96%. 1H ( N5M00R MHz, ) δ 7C.2D6C -I37.23 (m, 8H), 7.17 - 7.12 (m, 16H), 7.05 (s, 4H), 7.01 - 7.00 (m, 4H), 6.96 (s, 2H), 6.93 (s, 4H), 6.85 - 6.84 (m. 4H), 6.81 (s, 2H), 5.11 (s, 2H), 5.10 (s, 2H), 2.28 (s, 3H), 2.23 (s, 3H), 2.11 (s, 3H). 13C NMR (126 MHz, )C δD 1C7I36.15 (dd, J = 221.2, 15.7 Hz), 146.5 (d, J = 14.8 Hz) (Ctrz), 145.3, 143.4, 142.6, 141.8, 141.4, 141.1, 141.0, 140.0, 135.6, 130.5, 129.9, 129.7, 129.6, 129.2, 128.9, 128.7, 128.5, 127.1, 127.0, 126.8, 126.7, 123.4, 54.2, 51.2, 35.3, 22.0. HRMS (APCI): calcd for ChyHsrAgNs [M - 1]+ 1036.3599, found 1036.3602.

[0303]

[0304] [Ag(MIC-Dipp / IPr*DiPP)Cl], Yield = 96%. 1 (H50 N0M MRHz. ) δ 7.62CD (t.C JI3 = 7.8 Hz, 1H), 7.46 (t, J = 7.8 Hz, 1H), 7.32 (d, J = 7.9 Hz, 2H), 7.27 - 7.25 (m, 8H), 7.24 - 7.21 (m, 6H), 6.98 (s, 2H), 6.71 - 6.69 (d, J = 7.2 Hz, 4H), 6.64 (brs, 4H), 5.38 (s, 2H), 2.47 - 2.41 (m, 2H), 2.33 - 2.27 (m, 2H). 2.22 (s, 3H), 1.28 (d, J = 6.7 Hz, 6H), 1.20 (d. J = 6.8 Hz. 6H), 1.08 (d. J = 6.5 Hz, 6H), 0.60 (d, J = 6.3 Hz, 6H).13C NMR (126 MHz, ) δ 172.92 CDCI3

[0305] (dd, J = 238.3, 17.4 Hz), 146.51 (d, J = 17.4 Hz), 145.9, 145.0, 144.6, 143.6, 143.3, 139.9,

[0306] 135.7, 131.7, 131.5, 131.3, 130.1, 130.0, 129.4, 128.5, 128.3, 127.6, 126.8, 125.8, 124.6,

[0307] 124.5, 53.5, 29.9, 29.0, 27.3, 25.0, 24.5, 21.9, 21.7.

[0308] General Procedure for the Synthesis ofNHC-Cu Complexes

[0309] An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* HI or MIC-IPr* HBF4 (0.20 mmol, 1.0 equiv) and KOtBu (26.7 mg, 1.2 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, CuCl (39.6 mg, 0.4 mmol. 2.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 8 h. The reaction mixture was filtered through celite using 10 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from DCM / hexanes (1:10 v / vol) as a pale yellow solid.

[0310] [Cu(MIC-IPr* / PhMe)I] . Yield 7.50 - 7.49 (m, 3H), 7.40 - 7.38 (m, 2H), 7.30 - 7.27 (m, 4H), 7.25 - 7.19 (m, 8H), 7.09 (d, J = 7.4 Hz, 4H). 6.95 (d, J = 6.9 Hz, 4H), 6.69 (s, 2H), 5.64 (s, 2H), 3.60 (s, 3H), 2.22 (s, 3H).13C NMR (126 MHz, CDCI3) δ 147.4, 142.0, 141.5, 141.0, 140.4. 135.6, 130.1, 130.0, 129.7, 129.4, 129.3,

[0311] 129.3, 129.1. 128.3, 127.2, 126.9, 126.5, 76.9. 52.5. 36.8. 22.0. HRMS (APCI): calcd for C42H35CUN3 [M - 1]+ 644.2122, found 644.2115.

[0312] [Cu(MIC-IPr* / MesMe)I] . Yield = 78%. 1H (5 N00M MRHz, ) δ 7.3C0D -C 7I.327 (m. 4H), 7.23 - 7.17 (m. 8H), 7.11 (d. J = 7.5 Hz, 4H), 6.93 - 6.92 (m, 6H), 6.75 (s, 2H). 5.40 (s, 2H), 3.29 (s, 3H), 2.31 (s, 3H), 2.24 (s, 3H), 1.99 (s, 6H).13C NMR (126 MHz, ) 5 CDCI3

[0313] 146.0, 142.7, 141.9, 140.6, 140.55, 140.5, 137.9, 136.0, 130.4, 129.8, 129.5, 129.1, 128.9,

[0314] 128.3, 126.9, 126.6, 122.9, 51.5, 35.5, 22.1, 21.3, 20.9.

[0315] [Cu(MIC-IPr* / DippMe)I] Yield CD 7C.4I83 (t, J =

[0316] 7.8 Hz. 1H), 7.30 (t, J = 7.5 Hz, 4H), 7.24 - 7.22 (m, 6H), 7.19 (d, J = 7.1 Hz, 2H). 7.14 (d, J = 7.5 Hz, 4H), 6.93 (d, J = 7.2 Hz, 4H), 6.77 (s, 2H), 5.37 (s, 2H), 3.19 (s, 3H), 2.38 - 2.29 (m, 2H), 2.25 (s, 3H), 1.21 (d, J = 6.8 Hz, 6H), 1.16 (d, J = 6.9 Hz, 6H).13C NMR (126 MHz, CDCh) δ 149.0, 142.9, 142.0, 140.7, 140.3, 135.8, 131.5, 130.4, 129.8, 129.3, 128.9, 128.2, 126.9, 126.6. 123.7, 122.9, 51.6. 35.7, 31.4, 25.4, 23.3, 22.1. HRMS (APCI): calcd for

[0317] C48H47CUN3 [M - 1]+ 728.3061, found 728.3026. [Cu(MIC-IPr* / IPr*Me)I] Yield 7.21 - 7.17 (m. 10H), 7.14 - 7.12 (m, 18H), 7.01 - 7.00 (m. 4H), 6.97 (s, 2H), 6.94 - 6.93 (d, J = 8.1 Hz, 8H), 6.81 (s, 2H), 5.16 (s, 4H), 2.27 (s, 3H), 2.22 (s, 3H), 2.05 (s, 3H).13C NMR (126 MHz, CDCH) δ 172.1, 146.2, 145.2, 143.2, 142.7, 141.6, 141.5, 141.0, 140.8, 139.9, 135.4, 130.3, 129.7, 129.6, 129.5, 129.4, 129.4, 129.2, 128.7, 128.4, 128.4, 126.9, 126.8, 126.6, 126.5, 123.1, 54.1, 51.0, 35.0, 21.9. HRMS (APCI): calcd for C69H57C11N3 [M - 1]+ 990.3843, found 990.3843.

[0318] [Cu(MIC-IPr* / MesMe)Cl] Yield = 70%. 1H ( N50M0R MHz, ) δ 7.C29D -CI 73.27 (m, 4H), 7.21 - 7.17 (m, 8H), 7.10 (d, J = 7.2 Hz, 4H), 6.93 - 6.91 (m, 6H), 6.75 (s, 2H). 5.41 (s, 2H), 3.26 (s, 3H). 2.32 (s. 3H), 2.23 (s. 3H), 1.98 (s, 6H).13C NMR (126 MHz, ) 5 CDCI3

[0319] 167.7, 146.4, 142.8, 142.0, 140.6, 140.5, 138.0, 136.2, 130.4, 129.8, 129.5, 129.1, 128.8,

[0320] 128.3, 126.9, 126.6, 123.0, 51.6, 35.4, 22.0, 21.3, 20.9. HRMS (APCI): calcd for C45H41C11N3 [M - Cl]+ 686.2596, found 686.2632.

[0321] [Cu(MIC-IPr* / DippMe)Cl] Yield = 76%. ’H NMR (500 MHz, ) δ 7.C48D (Ct,I3 J = 7.8 Hz, 1H), 7.30 (t, J = 7.5 Hz, 4H), 7.24 - 7.21 (m, 6H), 7.17 (t, J = 7.2 Hz, 2H), 7.12 (d, J = 7.5 Hz, 4H), 6.92 (d, J = 7.1 Hz, 4H), 6.76 (s, 2H), 5.37 (s, 2H), 3.16 (s, 3H), 2.37 - 2.31 (m. 2H), 2.24 (s, 3H), 1.22 (d, J = 6.8 Hz, 6H), 1.15 (d, J = 6.9 Hz, 6H).13C NMR (126 MHz, CDCh) δ 167.7, 149.0, 145.8, 142.9, 142.1, 140.7, 140.4, 136.0, 131.5, 130.5, 129.8, 129.3,

[0322] 128.9, 128.2, 127.0, 126.6, 123.8, 123.1, 51.7, 35.7, 31.4, 25.4, 23.3, 22.0.

[0323]

[0324] [Pd(MIC-IPr* / lPr*Me)(cin)I], An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / IPr*Me HI (105.6 mg, 0.10 mmol, 1.0 equiv) and KOtBu (22.4 mg, 2.0 equiv) under the argon atmosphere. Dry' and degassed THF (1 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [{Pd(cin)Cl}2] (25.9 mg, 0.5 mmol, 0.5 equiv) in dry THF (1 mL) was added and the reaction mixture was stirred at room temperature for 12 h. The reaction mixture was filtered through celite using 5 mL of DCM. The solution was then concentrated under the reduced pressure and reprecipitated from diethyl ether / hexanes (1: 10 v / vol) as a yellow solid (112.2 mg, yield = 88%). 41 NMR (500 MHz, CDCI3) 8 7.54 (d, J = 7.3 Hz, 2H), 7.46 - 7.41 (m, 4H), 7.33 - 7.31 (m, 2H). 7.25 - 7.16 (m, 14H), 7.12 (d, J = 7.1 Hz, 2H), 7.09 - 6.96 (m, 15H), 6.85 (d, J = 1.4 Hz, 1H), 6.79 (d, J = 7. 1 Hz, 2H), 6.74 - 7.72 (m, 3H), 6.70 (d, J = 7.4 Hz, 2H), 6.56 (d, J = 7.3 Hz, 2H), 6.22 (s, 1H), 5.98 (s, 1H), 5.88 (s, 1H), 5.59 (s, 1H), 5.45 - 7.39 (m, 1H), 4.72 (d, J = 13.1 Hz. 1H), 3.38 (d. J = 6.7 Hz, 1H), 2.28 (s, 3H), 2.19 (s, 3H), 2.16 (d, J = 11.9 Hz, 1H), 1.37 (s, 3H).13C NMR (126 MHz, )C 8D 1C6I63.1. 145.5, 145.4, 144.8, 144.4, 144.13, 144.12, 143.9, 143.8, 143.1, 142.8, 142.7, 140.3, 140.0, 139.7, 139.1, 138.3, 136.8, 131.4, 131.3, 131.0, 130.7, 130.3, 130.1, 129.9, 129.84, 129.81, 129.06, 129.05, 128.74, 128.70, 128.4, 128.2, 128.1, 128.0, 127.9, 127.1, 126.6, 126.44, 126.39, 126.3, 126.1, 126.0, 125.9, 108.2, 89.5, 53.4, 53.3, 52.8, 51.4, 51.3, 35.7, 22.1, 21.9. HRMS (APCI): calcd for CvsHeeNsPd [M - I]+ 1150.4310, found 1150.4311.

[0325] General Procedure for the Synthesis of [(NHC)Pd(cin)Cl] Complexes

[0326] An oven-dried reaction tube equipped with a stir bar was charged with with MIC- IPr* HBF4 (0.20 mmol, 1.0 equiv) and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (1 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [{Pd(cin)Cl}2] (51.8 mg, 1.0 mmol, 0.5 equiv) in dry THF (1 mL) was added and the reaction mixture was stirred at room temperature for 12 h. The reaction mixture was filtered through celite using 5 mL of THF. The solution was then concentrated under the reduced pressure and reprecipitated from THF / hexanes (1: 10 v / vol) as a yellow solid.

[0327] [(MIC-IPr* / MesMe)Pd(cin)Cl. Yield = 78%. ’H NMR (500 MHz, ) δ 7.41C (DdC, I3 J = 7.4 Hz. 2H), 7.33 - 7.29 (m, 6H), 7.25 - 7.15 (m, 9H), 7.14 - 7.10 (m, 4H), 7.01 (s, 1H). 6.95 - 6.93 (m, 3H), 6.89 (d, J = 6.8 Hz, 2H), 6.72 (s, 1H), 6.68 (s, 1H), 5.98 (s, 1H), 5.73 (s, 1H), 5.31 - 5.25 (m, 1H), 4.61 (d, J = 12.9 Hz, 1H), 2.95 (s, 3H), 2.71 (d, J = 5.5 Hz, 1H), 2.343 - 2.338 (m, 6H), 2.21 (s, 3H), 2.10 (s, 3H), 1.87 (d, J = 11.6 Hz, 1H).13C NMR (126 MHz, CDCI3) 8 166.0, 144.0, 143.7. 142.9, 142.7. 142.5, 141.5, 140.4, 139.8, 139.3, 139.2,

[0328] 138.1, 137.7, 136.1, 130.3, 130.0, 129.8, 129.6, 129.2, 129.1, 129.0, 128.4, 128.4, 128.3,

[0329] 128.1, 128.0, 127.8, 127.2, 126.7, 126.5, 126.1, 125.7, 124.1, 108.5, 89.7, 50.8, 50.7, 45.8, 35.2, 22.0, 21.6, 21.5, 20.8. HRMS (APCI): calcd for Cs^soNsPd [M - Cl]+ 846.3053, found

[0330] 846.3070.

[0331] [(MIC-IPr* / DippMe)Pd(cin)Cl. Yield = 92%. 'l l NMR (500 MHz, ) 6 7.47C (Dt,CI3 J = 7.8 Hz, 1H), 7.39 (d, J = 7.2 Hz, 2H), 7.33 - 7.29 (m, 7H), 7.26 - 7.08 (m, 14H), 6.93 - 6.90 (m, 4H), 6.77 - 7.76 (m, 2H), 6.02 (s, 1H), 5.91 (s, 1H), 5.29 - 5.23 (m, 1H), 4.58 (d, J = 12.9 Hz, 1H), 3.01 (s, 3H), 2.89 - 2.84 (m, 1H), 2.76 - 7.71 (m, 1H), 2.65 (d, J = 6.6 Hz, 1H), 2.23 (s, 3H), 1.82 (d, J = 11.5 Hz, 1H), 1.46 (d, J = 6.6 Hz, 3H), 1.37 (d, J = 6.6 Hz, 3H), 1.11 (d, J = 6.8 Hz, 3H), 1.07 (d, J = 6.8 Hz, 3H).13C NMR (126 MHz, ) 8 167.3, 14C9D.7C, I3 148.9, 144.3. 143.7, 143.5, 142.8, 142.6, 141.2, 140.4, 139.3. 138.0, 136.3. 130.9, 130.4. 130.2, 130.1, 129.9, 129.1, 129.0, 128.6, 128.4, 128.3, 127.9, 127.9, 127.2, 126.8, 126.6,

[0332] 126.3, 126.1. 125.8, 124.1, 124.0, 123.6, 108.3, 90.3, 51.1, 51.1, 46.1, 36.2, 30.8, 30.6. 25.2.

[0333] 25.1, 24.7, 24.3, 22.1. HRMS (APCI): calcd for C57H56N?Pd [M - Cl]+ 888.3523, found 888.3504.

[0334] [(MIC-IPr* / IPr*Me)Pd(cin)ClJ. Yield = 86%. ‘H NMR (500 MHz, ) 8 7.5C8DCI3 (d, J = 7.4 Hz, 2H), 7.41 - 4.38 (m, 4H), 7.32 - 7.30 (m, 4H), 7.24 - 7.23 (m, 5H), 7.19 - 7.16 (m, 6H), 7.13 - 7.11 (m, 4H), 7.08 - 7.03 (s, 6H), 7.01 - 6.98 (m, 6H), 6.92 (s, 2H). 6.84 (s, 1H), 6.80 (d, J = 7.2 Hz, 2H). 6.75 - 7.71 (m, 5H), 6.63 (d, J = 7.8 Hz, 2H), 6.10 (s. 1H), 5.95 (s, 1H), 5.92 (s, 1H), 5.66 (s, 1H), 5.42 - 5.36 (m, 1H), 4.91 (d, J = 13.1 Hz, 1H), 2.90 (d, J = 6.5 Hz, 1H), 2.26 (s, 3H), 2.20 (s, 3H), 1.92 (d, J = 11.3 Hz, 1H), 1.48 (s, 3H).13C NMR (126 MHz, CDC) I 63 167.0, 145.3, 144.4, 144.2, 144.2, 144.1, 143.99, 143.97, 143.9,

[0335] 143.2, 142.5. 142.4, 140.1, 139.8, 139.5, 139.0, 138.0, 136.3, 131.1, 130.6, 130.4, 130.0.

[0336] 129.9, 129.8. 129.0, 128.9, 128.6, 128.6, 128.2, 128.1, 128.0. 127.5, 127.0. 126.5, 126.3.

[0337] 126.2, 126.2, 126.0, 125.9, 125.5, 108.8, 91.5, 53.4, 51.2, 51.2, 46.0, 35.5, 22.0, 21.8. HRMS (APCI): calcd for C78H66N3Pd [M - Cl]+ 1150.4310, found 1150.4287.

[0338] [(MIC-IPr* / IPr*Me)Ir(CO)2lJ. An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / IPr*Me HI (105.6 mg, 0.10 mmol, 1.0 equiv), and KOtBu (22.4 mg, 2.0 equiv) under the argon atmosphere. Dry' and degassed THF (1 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Ir(COD)Cl]2 (33.6 mg, 0.05 mmol, 0.5 equiv) in dry THF (0.5 mL) was added and the reaction mixture was stirred at room temperature for 16 h. Then, the solution was bubbled with CO (1 atm) and stirred at room temperature for 6 h. The resulting reaction mixture was concentrated under vacuum and purified by column chromatography (hexane / ethyl acetate = 98:2) to give the title product (86 mg, 66%). 1H NMR (500 MHz, )C δD 7C.3I39 (d, J = 7.7 Hz, 4H), 7.28 - 7.25 (m, 4H), 7.22 - 7.21 (m, 7H), 7.18 - 7.16 (m, 5H), 7.07 - 7.04 (m, 4H), 7.00 - 6.98 (m, 8H), 6.94 (s, 2H), 6.80 (s, 2H), 6.67 (d. J = 7.6 Hz, 4H), 6.60 (d, J = 7.6 Hz, 4H), 6.12 (s, 2H), 5.69 (s, 2H), 2.27 (s, 3H). 2.20 (s, 3H). 1.20 (s. 3H).13C NMR (126 MHz. ) 6 180.5,C 1D68C.I53, 161.8. 145.7, 144.8, 144.4, 143.9, 143.6, 142.4, 140.5, 140.2, 139.9, 136.0, 131.5, 130.9, 130.3, 129.9, 129.0, 128.8, 128.1, 128.1, 127.8, 126.7, 126.6, 126.3, 126.2, 124.6, 53.3, 51.6, 35.8, 22.0. HRMS (APCI): calcd for C71H58IIrN3O2 [M + H]+ 1304.3204, found 1304.3213.

[0339] [(MIC-IPr* / PhMe)Ir(CO)2IJ An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / PhMe HI (142.0 mg, 0.20 mmol, 1.0 equiv), and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Ir(COD)Cl]2 (67.2 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 6 h. Then, the solution was bubbled with CO (1 atm) and stirred at room temperature for 6 h. The resulting reaction mixture concentrated under vacuum and purified by short column chromatography (hexane / ethyl acetate = 95:5) to give the title product (138.0 mg. 72%). 1H NMR (500 MHz, ) δ 7.5C8D -C 7I.357 (m. 2H), 7.52 - 7.51 (m, 3H), 7.30 - 7.26 (m, 4H), 7.24 - 7.22 (m, 6H), 7.17 - 7.12 (m, 6H), 6.91 (d, J = 7.0 Hz, 4H), 6.73 (s, 2H), 6.02 (s, 2H), 2.95 (s, 3H), 2.23 (s, 3H).13C NMR (126 MHz, ) δ CDCI3

[0340] 181.2, 169.1, 160.6, 147.1, 143.1, 142.1, 142.0, 140.3, 135.7, 130.9, 130.4, 130.3, 130.2.

[0341] 129.2, 128.7. 128.3, 127.9, 127.5, 126.7, 126.2, 51.4, 36.5, 22.0. HRMS (APCI): calcd for C44H35lrN?O2 [M - 1]+ 830.2356, found 830.2364.

[0342] [(MIC-IPr* / MesMe)Ir(CO)2I] . An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / MesMe HI (150.3 mg. 0.20 mmol, 1.0 equiv). and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Ir(COD)Cl]2 (67.2 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 6 h. Then, the solution was bubbled with CO (1 atm) and stirred at room temperature for 6 h. The resulting reaction was passed through short celite filtration and concentrated under vacuum. Then, the product was dissolved in minimum amount of THF and reprecipitated using hexane. The pure product was filtered and dried under high vacuum to give the title product (184.0 mg, 92%). (5001 MHH NzM, R ) δ 7.29 - 7.2C6D (CmI3, 4H), 7.23 - 7.21 (m. 6H), 7.14 - 7.19 (m. 6H), 6.95 (s, 2H), 6.88 (d, J = 7.0 Hz, 4H), 6.75 (s, 2H), 5.91 (s, 2H), 2.72 (s, 3H), 2.32 (s, 3H), 2.23 (s, 3H), 2.22 (s, 6H).13C NMR (126 MHz, CDCh) δ 181.0, 169.3, 161.9, 145.7, 143.3, 142.5, 141.8, 140.5, 140.3, 138.4, 136.1, 130.6, 130.5, 129.5, 129.1, 128.2, 128.0, 126.7, 126.2, 123.1, 51.5, 35.3, 22.0, 21.7, 21.4. HRMS (APCI): calcd for C47H41IrN3O2[M -I]+ 872.2828, found 872.2820.

[0343] [(MIC-IPr* / DippMe)Ir(CO)2IJ An oven-dried reaction tube equipped with a stir bar was charged with MIC-IPr* / DippMe HI (158.8 mg, 0.20 mmol, 1.0 equiv), and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (2 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Ir(COD)Cl]2 (67.2 mg, 0.2 mmol, 1.0 equiv) in dry THF (1.0 mL) was added and the reaction mixture was stirred at room temperature for 6 h. Then, the solution was bubbled with CO (1 atm) and stirred at room temperature for 6 h. The resulting reaction mixture concentrated under vacuum and purified by short column chromatography (hexane / ethyl acetate = 95:5) to give the title product (145.9 mg. 70%). 1H (5 N00M MRHz, ) δ 7.4C7D (tC, I J3 = 7.8 Hz, 1H), 7.29 - 2.24 (m, 6H), 7.23 - 7.20 (m, 6H), 7.15 - 7.09 (m, 6H), 6.83 (d, J = 7.0 Hz, 4H), 6.71 (s, 2H), 6.02 (s, 2H), 2.81 - 2.75 (m, 1H), 2.71 (s, 3H), 2.21 (s, 3H), 1.39 (d, J = 6.7 Hz, 6H), 1.04 (d, J = 6.7 Hz, 6H).13C NMR (126 MHz, ) 6C 1D8C0I.38, 169.6, 162.1, 149.7, 144.4, 143.2, 142.8, 141.8, 140.2. 136.3, 131.5, 130.9, 130.5, 129.4, 128.1, 128.0, 126.7, 126.2, 124.2, 122.8.

[0344] 51.36, 36.51. 30.86, 25.9, 25.0, 22.0. HRMS (APCI): calcd for C50H47lrN3O2 [M - 1]+ 914.3296, found 914.3311.

[0345] General Procedure for the Synthesis of [(NHC)Ir(cod)ClJ and [(NHC)Rh(cod)ClJ Complexes

[0346] An oven-dried reaction tube equipped with a stir bar was charged with MIC- ipr* HBF4 (0.20 mmol, 1.0 equiv) and KOtBu (44.8 mg, 2.0 equiv) under the argon atmosphere. Dry and degassed THF (1 mL) was added to the mixture and stirred at room temperature for 20 min. After that, [Ir(cod)Cl]2 or [Rh(cod)Cl]2 (0. 1 mmol. 1.0 equiv) in dry THF (0.5 mL) was added and the reaction mixture was stirred at room temperature for 6 h. The reaction mixture was filtered through celite using 5 mL of THF. The solution was then concentrated under the reduced pressure and reprecipitated from THF / hexanes (1 : 10 v / vol) to afford the product as a yellow or reddish-yellow solid.

[0347] [(MIC-IPr* / MesMe)Ir(cod)ClJ. Yield = 80%. 1H (5 N00M MRHz, ) δ 7.3C1 D -CI3 7.25 (m, 8H), 7.20 (t, J = 7.0 Hz, 2H)), 7.12 - 7.05 (m, 6H), 6.95 (s, 2H), 6.89 (d, J = 7.0 Hz, 4H), 6.76 (s, 2H), 5.98 (s, 2H), 4.44 - 4.43 (m, 2H), 3.07 - 3.05 (m, 2H), 2.73 (s, 3H), 2.33 (s, 3H), 2.25 (s, 3H), 2.21 (s. 6H), 2.00 - 1.97 (m, 2H), 1.77 - 1.71 (m, 2H), 1.54 - 1.48 (m, 2H), 1.33 - 1.27 (m. 2H).13C NMR (126 MHz, ) δ 173C.D0,C 1I638.5. 163.6, 144.0. 143.7, 143.2, 141.8, 139.6, 139.3, 139.0, 136.9, 130.4, 130.0, 129.4, 128.7, 128.2, 127.9, 126.4, 125.9, 124.7, 81.5, 52.3, 51.3, 35.0, 33.6, 29.3, 22.0, 21.7, 21.4, 13.6. HRMS (APCI): calcd for C53H53lrN3 [M - Cl]+ 924.3869, found 924.3859.

[0348] [(MIC-IPr* / DippMe)Ir(cod)ClJ. Yield = 71%. 1H (50 N0M MRHz, ) δ 7.4C7 D (t,CI3 J = 7.8 Hz, 1H), 7.38 - 7.36 (m, 4H), 7.29 - 7.24 (m, 6H), 7.20 (1, J = 7.2 Hz, 2H), 7.13 - 7. 10 (m, 4H), 7.08 - 7.05 (m, 2H). 6.85 (d, J = 7.2 Hz, 4H). 6.69 (s, 2H). 6.27 (s. 2H), 4.47 - 4.46 (m, 2H), 2.98 - 2.96 (m, 2H), 2.81 - 2.68 (m, 2H), 2.66 (s, 3H), 2.20 (s, 3H), 2.07 - 1.98 (m, 2H), 1.71 - 1.69 (m, 2H), 1.48 - 1.52 (m, 2H), 1.38 - 1.39 (m, 6H), 1.22 - 1.16 (m, 2H), 1.03 (d, J = 6.8 Hz, 6H).1?C NMR (126 MHz. ) δ 167C.D7,C 1I439.7, 144.0, 142.3, 141.6, 139.0, 137.5. 130.8, 130.6, 130.4, 129.4, 128.0, 127.8, 126.4, 125.8, 125.1. 123.9, 81.9, 52.8, 51.4, 35.8, 33.4, 30.8, 29.2, 25.1, 24.4, 22.0. HRMS (APCI): calcd for CNHMrN? [M - Cl]+ 966.4333, found 966.4332.

[0349] [(MIC-IPr* / MesMe)Rh(cod)ClJ. Yield = 72%. 1 (H50 N0M MRHz, ) δ 7.35C -DCI3 7.33 (m, 3H), 7.29 - 7.27 (m, 3H). 7.20 (1. J = 7. 1 Hz. 2H), 7.01 - 7.04 (m. 6H), 6.98 (s, 2H), 6.89 (d, J = 7.3 Hz, 4H), 6.80 (s, 2H), 6.01 (brs, 2H), 4.85 - 4.83 (m, 2H), 3.36 - 3.34 (m, 2H), 2.75 (s, 3H), 2.34 (s, 3H), 2.27 (s, 3H), 2.24 (s, 6H), 2.16 - 7.08 (m, 2H), 1.93 - 1.85 (m, 2H), 1.73 - 1.67 (m, 2H), 1.63 - 1.57 (m, 2H). HRMS (APCI): calcd for C53H53RI1N3 [M - Cl]+ 834.3294, found 834.3278.

[0350] [(MIC-IPr* / DippMe)Rh(cod)ClJ. Yield = 94%. 1H (5 N00M MRHz, ) δ 7.4C8DCI3 (t, J = 7.8 Hz, 1H), 7.4 (d, J = 7.4 Hz, 4H), 7.29 - 7.26 (m, 6H), 7.21 - 7.18 (m, 2H), 7.12 - 7.09 (m, 4H), 7.07 - 7.04 (m, 2H). 6.84 (d, J = 7.2 Hz, 4H), 6.72 (s, 2H), 6.31 (s, 2H), 4.93 - 4.88 (m, 2H), 3.36 - 3.32 (m, 2H). 2.92 - 2.68 (m, 2H). 2.64 (s. 3H), 2.22 (s. 3H), 2.19 - 2.13 (m, 2H), 1.87 - 1.78 (m, 2H), 1.72 - 1.67 (m, 2H), 1.53 - 1.49 (m, 2H), 1.44 - 1.43 (m, 6H), 1.02 (d, J = 6.8 Hz, 6H).13C NMR (126 MHz, CDCI3) 169.1, 168.7, 149.9, 144.1, 141.9, 141.6, 138.9, 137.8, 130.8, 130.6, 130.5, 129.4, 128.1, 127.7, 126.4, 125.7, 125.4, 123.9, 96.0, 95.9, 69.7, 69.6, 51.4, 35.7, 32.7, 30.8, 28.7. 25.1, 24.5, 22.0. HRMS (APCI): calcd for C56H59RI1N3 [M - Cl]+ 876.3759, found 876.3761.

[0351] Example 3: Synthesis of MIC-IPr* ligands by click reaction

[0352] The synthesis of MIC-IPr* was initiated through the Friedel-Crafts benzylation of p- toluidine to afford 2.6-dibenzhydryl-4-methylaniline (6). With access to 2,6-dibenzhydryl-4- methylaniline (6), amine to azide interconversion furnished aryl azide 7 in 89% yield by an optimized procedure with tert-butyl nitrite (2.5 equiv) and trimethylsilyl azide (1.8 equiv) added consecutively to the acetonitrile solution of 6 at 0 °C and stirring for 3 h at room temperature (FIG. 2). In parallel, iodobenzene 8 was synthesized from 2.6-dibenzhydiyl-4- methylaniline (6) by in situ diazotization / iodination using p- toluene sulfonic acid, sodium nitrite and potassium iodide (FIG. 2). After extensive optimization, it was found that this reaction provided the best results using 'BuOH / McCN / FhO (9:9:2) as a solvent mixture to overcome solubility issues.

[0353] Next, the key Sonogashira cross-coupling step was addressed. Initial attempts established that the known routes for the Sonogashira cross-coupling of sterically-demanding aryl iodides using TMS-acetylene as the alkyne precursor provided the ene-yne dimerization product as the major product. Thus, the Sonogashira cross-coupling step was extensively optimized, where it was found that the more sterically hindered TIPS-acetylene as the starting alkyne provided optimal results. In this case, bulky TIPS-acetylene prevents the ene-yne dimerization of the desired product. The optimum conditions involve heating the mixture of aryl iodide 7 (1.0 equiv) and TIPS-acetylene (3.0 equiv) in presence of Pd(PPh3)2C12 (5 mol%) and Cui (7 mol%) in toluene / 'PnNH at 65 °C to afford the TIPS-alkyne, 9 cross- coupled product, which was subjected in situ to TBAF deprotection to deliver the desired terminal alkyne 10 in 84% overall yield (FIG. 2).

[0354] With both ‘click’ partners 7 and 10 in hand, the click reaction was performed. Although the reaction was completely ineffective following literature procedures for the triazole click reaction of hindered substrates, after extensive optimization, it was found that using THF / MeCN / H2O (3:2: 1) as the solvent mixture in the presence of CuSCh (25 mol%) and sodium ascorbate (60 mol%), the desired triazole product 11 was cleanly obtained in 78% yield (FIG. 2). Finally, N-methylation of triazole 11 using methyl iodide or trimethyloxonium tetrafluoro borate (Meerwein’s reagent) afforded the MIC-IPr* as HI or HBF4salt 12 (FIG. 2).

[0355] The synthetic route designed and demonstrated herein is highly practical. With the exception of the aryl iodide synthesis, all steps have been optimized in order not to require any chromatographic purification, permitting ready access to the desired ligand on multigram scale.

[0356] Example 4: Properties of MIC-IPr* ligands and catalyst complexes thereof

[0357] With multigram scale access to MIC-IPr*, the electronic and steric properties of the 1 / 7-1, 2,3-triazol-5-ylidene ligand was examined (FIG. 3). First, to evaluate the steric properties, the linear gold complex [Au(MIC-IPr*)I] 13 was synthesized using triazolium 12a (X = I) in the presence of KO'Bu and Au(Me2S)Cl. The analogous [Au(MIC-IPr*)Cl] 14 complex was synthesized from triazolium 12b (X = BF4) under similar conditions. In the first case, the gold-iodide complex is formed because of the higher stability of the Au-iodide bond. Complexes 13 and 14 were fully characterized by x-ray crystallography (FIGs. 4A-4B).

[0358] Both [Au(MIC-IPr*)I] (13) and [Au(MIC-IPr*)Cl] (14) feature a linear geometry (C- Au-I, 173.94°, C-Au, 1.997 A, and C-Au-Cl, 177.81°; C-Au, 1.984 A), and thus present good models for evaluating %V / W. Studies by Nolan, Cavallo and co-workers established the %buried volume (%V^r) and steric maps of NHC-metal complexes as a method of choice for evaluating the steric impact of NHC ligands. Complexes 13 and 14 are characterized by the %buried volume (%Vw) of 51.2% and 48.2%, respectively. The quadrant distribution is SW 69.4%, NW 41.2%, NE 48.5%, SE 45.6% and SW 53.3%, NW 57.7%, NE 41.9%, SE 40. 1% for 13 and 14, respectively. These values can be compared with [Au(IPr*)Cl] (C-Au-Cl, 178.3°; C-Au, 1.987 A) and [Au(MIC-Dipp)Cl] (C-Au-Cl, 178.5°; C-Au, 1.992 A, as well as with %Nbur of 50.4% and 43.2% for [Au(IPr*)Cl] and [Au(MIC-Dipp)Cl], respectively. There is an additional difference in quadrant distribution for gold-MIC-IPr* complexes with [Au(MIC-IPr*)I] featuring a higher SW / NE of 69.4% / 48.5% and lower NW / SE of 41.2% / 45.6% vs. [Au(IPr*)Cl] (SW / NE of 60.2% / 41.7% and NW / SE of 52.8% / 47.0% / ).

[0359] Next, to evaluate the p-backbonding properties, the selenourea complex [Se(MIC- IPr*)] 15 was synthesized by reacting triazolium 12 with KO'Bu in the presence of selenium. The77Se NMR value of 66.0 ppm (CDCh) of 15 can be compared with the classical imidazol-2-ylidenes, [Se(IPr*)], dse= 106 ppm (CDCh), and unhindered l,4-bis(phenyl)- H / -l,2,3-triazol-5-ylidenes, [Se(PhPh-Trz), dse = 23 ppm (CDCI3)], indicating intermediate p-backbonding affinity of MIC-IPr*.

[0360] To determine the Tolman electronic parameter (TEP), [Ir(MIC-IPr*)(CO)2l] 16 was synthesized. The Tolman electronic parameter provides a valuable measure of the overall electronic contribution of NHC ligands. Thus, the reaction of triazolium 12a with [Ir(cod)Cl]2 in the presence of KO'Bu afforded [Ir(NHC)(cod)I] complex, which was followed by the insertion of CO to deliver the [Ir(MIC-IPr*)(CO)2l] 16 in 66% yield. The CO stretching frequencies of [Ir(MIC-IPr*)(CO)2l] are nsym = 2057.6 cm"1and nasym= 1978.8 cm’1(CH2CI2, 0.20 M), respectively, which corresponds to a TEP of 2046.6 cm"1. These values can be compared with the classical imidazol-2-ylidenes, IPr* (TEP of 2052.7 cm"1), and strongly s- donating cyclic (alkyl)(amino)carbenes, CAACCy(TEP of 2048.6 cm’1), indicating that MIC-IPr* is significantly stronger electron-donating ligand. Furthermore, the VC-H coupling of NHC salts provides a good evaluation of the s-donation of N-heterocyclic carbenes. Thus, 210.40 Hz (MIC-IPr* HI, CDCI3) is significantly lower than that of IPr* HC1 (224.99 Hz, CDCh), indicating a significantly better o-donation of MIC-IPr* than the classical imidazole-2-ylidenes.

[0361] The “flexible steric bulk” of MIC-IPr* is evident from the synthesis and full crystallographic characterization of [Pd(MIC-IPr*)(cin)I] 17 (FIG. 5), where N1 / C4 wingtips of the bulky MIC-IPr* adapted to the steric adjustment of the square-planar Pd(II) center coordinated to / f'-cinnamyl group to fit Pd-coordination plane (FIG. 5). Complex 17 was synthesized the reaction of [Pd(cin)Cl]2 with the MIC-IPr* carbene generated using KO'Bu in THF. The steric map of [Pd(MIC-IPr*)(cin)I] 17 shows the %buried volume (%Vtar) of 40.9% with the unsymmetrical distribution SW 24.8%, NW 58.7%, NE 27%, SE 53.3% for each quadrant (FIG. 6B). These values can be compared with the (%Vtar) of 51.2% for the [Au(MIC-IPr*)I] complex and 43.4% of [Pd(IPr*)(cin)Cl] with SW 24.8%, NW 63.9%, NE 32.9%, SE 52.0% for each quadrant The C-Pd and Pd-C(Ph) bond lengths of 2.048 A, and 2.285 A in 17 are longer than for ([Pd(IPr*)(cin)Cl] complex of Pd-C 2.038(6); Pd-C(Ph), 2.155 A.

[0362] Table 1. Summary of steric and electronic parameters of MIC-IPr* aMenthyl instead of cyclohexyl;bMe2 instead of cyclohexyl; nd = not determined.

[0363] Example 5: Catalytic activity of exemplary MIC-IPr* catalysts

[0364] The catalytic activity of MIC-IPr* was briefly evaluated in gold-catalyzed electrophilic functionalization reactions (FIGs. 7A-7E). At present, the classical imidazole- ylidene, IPr, is the ligand of choice in the Au(I)-NHC reactivity platform to realize many valuable transformations. Thus, reactivity of sterically -hindered MIC-IPr* in Au(I)-catalysis was benchmarked. First, [Au(MIC-IPr*)I] -catalyzed intramolecular cyclization ofy-alkynoic acid 18 in presence of sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaBArF4) was accomplished in DCE at 50 °C at 0.05 mol% loading in 98% yield (FIG. 7A). To enable direct comparison, [Au(MIC-IPr*)Cl] was also tested and provided slightly better reactivity (FIG. 7A, 75% yield, 0.01 mol%). The observed reactivity of [Au(MIC-IPr*)Cl] (TON = 7,500) outperforms the classical imidazol-2-ylidene [Au(IPr*)Cl] (TON = 2,500). It is worthwhile to note that [Au(MIC-IPr*)Cl] is also more reactive than the recently reported ylide-functionalized phosphines, which are among the most reactive ligands in Au(I)- catalyzed electrophilic functionalizations.

[0365] Next. [Au(MIC-IPr*)I]-catalyzed hydroamination of phenyl acetylene with aniline was accomplished at 0.5 mol% catalyst loading (99% yield; 0.05 mol%, 52% yield) (FIG. 7B). In this case, similar reactivity of [Au(MIC-IPr*)Cl] was also observed (0.05 mol%, 84% yield), again outperforming the classical [Au(IPr*)Cl] (0.05 mol%, 54%) under these conditions. Furthermore. [Au(MIC-IPr*)Cl] -catalyzed cycloisomerization of 7V-propargyl amide 23 proceeded quantitatively at very low 0.02 mol% catalyst loading in the presence of AgOTf in DCE at 50 °C (FIG. 7C). The triazole-based MIC-IPr* (TON = 7,300) again outperformed the classical imidazol-2-yldiene IPr* (TON = 5,400).

[0366] Finally, it was determined that [Au(MIC-IPr*)Cl] 14 could also be used for direct coupling of unactivated p-systems, such as aryl / alkyne coupling (FIG. 7D) and [2+2] cycloaddition (FIG. 7E). It is worth noting that these reactions have mainly relied on gold- phosphine complexes. In the intramolecular cyclization, [Au(MIC-IPr*)Cl] 14 was successful in the presence of NaBArF4 at room temperature at very7low 0.02 mol% catalyst loading, which is advantageous over gold-phosphine complexes where more than 1 mol% gold-catalyst was used for this cyclization. In the [2+2] cycloaddition, [Au(MIC-IPr*)Cl] 14 afforded the desired cyclobutene product at 0.3 mol% loading, which is 1.7 times better than ylide-functionalized phosphines, and almost 10 times improvement in catalytic efficiency over the previously reported catalysts. Given its general reactivity in highly valuable Au(I)- catalyzed functionalizations. [Au(MIC-IPr*)Cl] opens widespread possibilities in catalysis.

[0367] Example 6: DFT studies of MIC-IPr* ligands

[0368] To gain insight into the electronic properties of MIC-IPr*, HOMO and LUMO energy levels were determined at the B3LYP 6-31 l++g(d,p) level (FIGs. 8A-8B). It is now well-established that HOMO and LUMO energy levels provide the most accurate evaluation of nucleophilicity (more s-donating, higher HOMO) and electrophilicity (more p-accepting, lower LUMO) of N-heterocyclic carbenes, while the comparison must be available at the same level of theory. Most crucially, the HOMO of MIC-IPr* (-5.72 eV) clearly indicates a much better s-donor capability than the classical imidazol-2-ylidenes, such as IPr (-6.01 eV) and IPr* (-6.12 eV). The LUMO of MIC-IPr* (-1.18 eV) can be compared with IPr (-0.48) and IPr* (-0.90 eV), indicating that it is more p-accepting. Furthermore, p-donating orbital (HOMO-1) of MIC-IPr* is -6.31 eV, which can be compared with IPr (-6.55 eV) and IPr* (- 6.28 eV). Thus, the strong o-donation of MIC-IPr* together with unsymmetrical steric bulk renders this class of ‘click triazole?NHC ligands as highly attractive candidates for stabilization of metal centers in organometallic chemistry and catalysis.

[0369] Example 7: Design and synthesis of unsymmetrical MIC-IPr* ligands

[0370] The unsymmetrical MIC-IPr* ligands selected for this study are shown in FIG. 9. These ligands were designed to gradually vary by the steric demand of the C5 wingtip in the order of Ph < Mes < Dipp in the presence of the N3-flexible IPr* substituent. An exemplary synthesis of unsymmetrical MIC- IPr* ligands is shown in FIG. 10, which is commenced by the Friedel-Crafts benzylation of / ^-toluidine with diphenyl methanol to afford 2,6- dibenzhydryl-4- methylaniline in 92% yield. Next, amine to azide interconversion was accomplished through an optimized, consecutive addition of tert-buty l nitrite (2.5 equiv) and trimethylsilyl azide (1.8 equiv) to the sterically -hindered aniline 6 in acetonitrile at 0 °C and warming to room temperature for 3 hours to afford aryl azide 7 in 89% yield (FIG. 10). In parallel, the alkyne coupling partners for the click cycloaddition, 2-iodo-l,3,5- trimethylbenzene 35 and 2- iodo-l,3-diisopropylbenzene 36, were synthesized from the corresponding 2,4,6-trimethylaniline 32a and 2,6- diisopropylaniline 32b by a standard diazonium formation / iodination (FIG. 10). Thus, the reaction of ary l anilines with an excess amount of / 7-toluenesulfonic acid in a / BuOH / FLO (24: 1). followed by a dropwise addition of sodium nitrite and potassium iodide afforded the aryl iodide products 33-34, which were further utilized for Sonogashira cross-coupling. The desired terminal alkynes 35 (90%) and 36 (54%) were directly obtained by using Pd(PPhs)2C12, Cui and TMS-acetylene (1.5 equiv) as the coupling partner, followed by in situ TMS deprotection with K2CO3 in methanol (FIG. 10). Having secured access to both aryl azide and aryl alkyne coupling partners, the ‘click triazole’ synthesis was next explored. First, methods previously reported in the literature were used for the synthesis of sterically -hindered azides, however, these attempts were largely unsuccessful due to solubility issues of aryl azide 32 in water. After extensive optimization, it was determined that this challenging click reaction works successfully in THF / MeCN / H2O (3:2: 1) as the solvent mixture (FIG. 10). Thus, aryl azide 32 (1 equiv), alkyne (1.5 equiv), CuSO4 (20 mol%) and sodium-ascorbate (60 mol %) smoothly afforded the desired triazole products 37a (85%), 37b (70%). 37c (74%). Finally, methylation of triazoles 37a-37c with methyl iodide or Meerwein’s reagent (MesOBFr) provided the desired triazolium precursors as iodide 38 and tetrafluoroborate 39 salts (FIG. 10). Crucially, the developed synthetic route is highly practical and could be routinely performed on a multigram scale.

[0371] Example 8: Selected properties of exemplary ligands and metal complexes thereof

[0372] Having developed a robust synthetic route to access iodide and tetrafluoroborate triazolium salts 38-39, the next goal was to evaluate steric and electronic properties of unsymmetrical H7-l,2,3-triazol-5-ylidene ligands. First, to determine geometric properties of MIC-IPr* ligands, linear [Au(NHC)X] (X = Cl. I) complexes were synthesized using ligands 38a-38c and 39b- 39c. Linear [Au(NHC)Cl] complexes serve as best models for quantifying the steric impact of NHC ligands. These reactions proceeded smoothly in the presence of / BuOK and Au(Me2S)Cl (FIG. 11). The use of iodide triazolium salts 38a-38c resulted in the formation of [Au(NHC)I] complexes 40a-40c, while tetrafluoroborate salts 39b-39c afforded [Au(NHC)Cl] complexes 41b-41c under similar conditions.

[0373] Gold(I) complexes 40a, 40b and 40c were fully characterized by x-ray crystallography (FIGs. 12A-12C). The X-ray cry stallographic analysis revealed that Au is linearly bound to the carbene atom in the unsymmetrical MIC-IPr* complexes 40a-40c (FIGs. 12A-12C). Interestingly, the less sterically -hindered [Au(MIC-IPr* / Ph)I] 40a complex crystallized as a dimer, while the more sterically-demanding [Au(MIC-IPr* / Mes)I] 40b and [Au(MIC-IPr* / Dipp)I] 19c complexes crystallized as monomers. The Au-C bond length in 40a is 2.015 A, which is slightly longer than the corresponding Au-C bond length in the monomeric complexes 40b and 40c of 1.998 A and 1.987 A, respectively.

[0374] The observed Au-C bond lengths in 40b-c are in the range of the symmetrical [Au(MIC-IPr* / IPr*)I] complex (1.997 A). Furthermore, the observed Au-C bond lengths are in the range of monomeric Au(I) complexes supported by l / 7-l,2,3-triazol-5- ylidenes ([Au(MIC-Dipp / Ph)Cl], [Au(MIC-IPr)Cl]). The Au-I bond length in 40b-40c exceeds that of the Au-C, as expected in gold-carbene complexes. The Au-I distance in 40b is 2.5361 A and in 40c is 2.5270 A). These values can be compared with the Au-I bond lengths in [Au(MIC-IPr*)I] (2.5299 A) and [Au(MIC-IMs)!] (2.5576 A) complexes. Furthermore, the C- Au-I angle in 40c (172.4°) is slightly more bent than 40b (178.03°) due to the larger steric impact of the Dipp wingtip. These values can be compared with the C-Au-I angle of 177.07° observed in the [Au(MIC-IMs)!]. Thus, with the increase of steric bulk of the wingtip from Mes to Dipp, there is some distortion from linearity and the C-Au-I angle decreases.

[0375] Next, a %percent buried volume (%VZwr) method was used, which has been previously described in the literature, to quantify the steric impact of unsymmetrical MIC- IPr* ligands. The %Nbur for 40a-40c along with the representative 1H- l,2,3-triazol-5- ylidenes ([Au(MIC-Dipp / Ph)Cl], [Au(MIC-IMs)!]. [Au(MIC-IPr)Cl]) is shown in FIGs. 13A-13F. The comparison of steric impact between |Au(MIC-IPr* / Ph)IJ 40a and (Au(MIC- Dipp / Ph)Cl] showed that 40a features a significantly bigger steric impact (%Vbur of 37.8% vs. 32.8%) (FIGs. 13A-13B). There is a more pronounced steric impact in 3 quadrants of MIC-IPr* / Ph than MIC-Dipp / Ph, indicating the spatial effect of the bulky IPr* substituent (SW. 43.1% vs. 38.1%; NW, 49.0% vs. 34.5%; NE. 33.7% vs. 24.9%; SE, 25.5% vs. 33.8%).

[0376] Furthermore, the complex [Au(MIC-IPr* / Mes)I] 40b and [Au(MIC-IMs)CI] showed a similar trend, where 40b is characterized by a significantly larger steric impact (%Nbur 39.4% vs. 32.0%) (FIGs. 13C-13D) with the biggest difference in SW and NW quadrants impacted by the IPr* substituent (SW. 51.9% vs. 37.1%; NW, 46.3% vs. 35.2%). Finally, the complex [Au(MIC- IPr* / Dipp)I] 40c is characterized by %Nbur of 44.9%, which can be compared with the °ANbur of 43.2% for [Au(MIC-IPr)Cl] and the %Vbur of 51.2% for the symmetrical [Au(MIC-IPr* / IPr*)I] (Fig. 3E vs. 3F). In this case, the largest steric impact of MIC- IPr* / Dipp is in the SE quadrant (49.0 vs. 39.0). while the NW and NE quadrants can be compared with MIC-IPr (NW, 42.8% vs. 47.1%; NE, 40.9% vs. 43.2%).

[0377] Next, [Se(MIC-IPr*)J complexes 42a-42c were synthesized to assess the n-accepting properties of the unsymmetrical MIC- IPr* ligands (FIG. 14). The reaction of triazolium 38a-38c with KO / Bu (2.0 equiv) and an excess of selenium powder (3 equiv) in THF afforded the desired Se-adducts in 83-90% yields. The77Se NMR shifts of [Se(MIC- IPr* / Ph)] 42a, [Se(MIC-IPr* / Mes)] 42b, and [Se(MIC-IPr* / Dipp)] 42c are 9 ppm, 0 ppm and 29 ppm, respectively. These values can be compared with the77Se NMR shift of the symmetrical [Se(MIC-IPr* / IPr*)],77Se = 66 ppm, indicating that the ^-accepting affinity in the series increases in the general direction of increasing the steric bulk at the wingtips. These values can be further compared with the classical imidazol-2-ylidenes, such as IPr (77Se = 90 ppm) and IPr* (77Se = 106 ppm) and cyclic (alkyl)(amino)carbenes, such as CAACCy(77Se = 492 ppm).

[0378] To study the electronic properties of the unsymmetrical MIC-IPr* ligands, the Tolman electronic parameter (TEP) of [Ir(MIC-IPr*)(CO)2l] complexes was measured. The TEP values provide the overall electronic contribution of the ligands, including o-donating and a-accepting properties. Although the previous methods for the synthesis of 127-1,2,3- triazol-5-ylidene complexes of the type [Ir(MIC)(CO)2l] were very low yielding, it was found that using bulky ligands, the corresponding [Ir(MIC-IPr*)(CO)2l] complexes could be synthesized in good yields (FIG. 15). Thus, the synthesis of [Ir(MIC-IPr*)(cod)I] proceeded uneventfully from the triazolium salts 38a-38c in the presence of [Ir(cod)Cl]2 and KO / Bu as the base. Next, carbon monoxide was purged through the THF solution of [Ir(MIC- IPr*)(cod)I] to afford [Ir(MIC-IPr*)(CO)2l] complexes 43a-43c.

[0379] The measured CO stretching frequencies of [Ir(MIC- IPr* / Ph)(CO)2l] 43a are vsym= 2056.7 cm’1and vasym= 1975.0 cm’1(CH2CI2, 0.20 M), and TEP is 2044.6 cm’1(Table 2). These values can be compared with the more sterically-demanding complexes in the series, [Ir(MIC-IPr* / Mes)(CO)2l] 43b of vsym= 2056.7 cm’1and vasym= 1975.6 cm’1and TEP of 2044.9 cm’1, and [Ir(MIC-IPr* / Dipp)(CO)2l] 43c of vsym= 2057.6 cm’1and vasym= 1975.0 cm’1and TEP of 2045.0 cm’1. These results indicate that the overall electronic properties of the unsymmetrical MIC-IPr* ligands 38a-38c are comparable; however, their steric properties are vastly different and gradually increase in the direction of IPr* / Dipp > IPr* / Mes > IPr* / Ph. It should be noted that these unsymmetrical l / f-1.2.3-triaz.ol-5-ylidenes are significantly stronger electron-donors than the classical imidazol-2-ylidenes, such as IPr (TEP of 2051.5 cm’1) and IPr* (TEP of 2052.7 cm’1), and also strongly donating cyclic (alkyl)(amino)carbenes, such as CAACCy(TEP of 2048.6 cm’1), and can be compared with other 127-l,2,3-triazol-5-ylidene complexes.

[0380] Table 2. Summary of steric and electronic parameters of MIC-IPr*.

[0381] “Menthyl instead of cyclohexyl;bMe2 instead of cyclohexyl; nd = not determined.

[0382] The Ir-carbonyl complexes 43a, 43b and 43c were stable to standard isolation conditions and fully characterized by x-ray cry stall ography (FIGs. 16A-16C). The geometry around the metal center is distorted square planar. The Ir-CO bonds for the 43a (1.915 A and 1.948 A), 43b (1.850 A and 1.879 A) and 22c (1.907 A and 1.967 A) were also in a same range, but longer than the reported Ir carbonyl complex (1.822 and 1.880 A). The C-Ir bond lengths in 43a, 43b and 43c are 2.075 A, 2.081 A and 2.082 A respectively. These values can be compared with the corresponding Ir-complexes of 17 / - 1 ,2,3-triazol-5-ylidene complexes.

[0383] The strong o-donating character of the unsymmetrical MIC- IPr* ligands is also evident from the VC-H coupling constants of the azolium salts (Table 2). The triazolium salt MIC- IPr* / Mes HI 38b is characterized by the Vc-n coupling of 209.8 Hz, while the triazolium MIC-IPr* / Dipp HI 38c is characterized by VC-H = 209.9 Hz. These values can be compared with the symmetrical MIC-IPr* / IPr* HI with VC-H of 210.4 Hz. The VC-H coupling constant could not be determined accurately for MIC- IPr* / Ph HI 38a due to peak overlap. These values can be compared with the representative imidazol-2-ylidenes, such as IPr HC1 (VC-J^ 223.7 Hz) and IPr* HC1 (’. / <' n = 225 Hz), indicating significantly higher o-donating capabilities of MIC-IPr* ligands.

[0384] Example 9: Catalytic activity of exemplary unsymmetrical MIC-IPr* catalysts

[0385] The present disclosure further describes the performance of the unsymmetrical MIC- IPr* ligands described herein in certain catalytic reactions. Gold(I)-catalysis was selected due to the tremendous importance of this catalysis platform in modem organic synthesis and catalysis to effect synthetically valuable transformations. The soft, carbophilic Lewis acidic nature of Au(I) enables mild 7t-activation, a strategy which has become extremely popular in homogeneous catalysis. Although the early studies mainly relied on Au(I)-phosphine complexes, in recent years, Au(I)-NHCs have been established as a more reactive alternative to gold(I)-phosphines (e.g, imidazol-2-ylidene, IPr), which at present is the ligand of choice in the Au(I)-NHC reactivity platform. The enhanced catalytic reactivity of Au(I)-NHC complexes compared to their phosphine counterparts is often attributed to their superior o- donor capacity and steric demand.

[0386] First, the effect of the unsymmetrical MIC- IPr* ligands on the Au(I)-catalyzed intramolecular cyclization of y-alkynoic acid was evaluated (FIG. 17). This reaction was performed in the presence of Au-catalyst and NaBAr1^ in DCE at 50 °C. It was found that the unsymmetrical MIC-IPr* complexes 40a-40c are effective at very low catalyst loading (0.01 mol%). An increase in the yield was observed by changing the counterion to chloride (FIG. 17). Hence, gold-chloride MIC-IPr* complexes 41 were more effective than the corresponding gold-iodide complexes 40. The most reactive in the series unsymmetrical MIC-IPr* / Dipp ligand showed comparable reactive to the symmetrical MIC-IPr* / IPr* (FIG. 17) and much higher than a representative imidazol-2-ylidene-based catalyst (FIG. 17). Furthermore, a gradual increase in yield of the cyclization product 19 was observed with increasing the steric bulk of the catalyst (FIG. 17). The catalyst comparison study also showed differences in the cycloisomerization yield are governed by both steric bulk and electronic effect (FIG. 17). This gradual steric differentiation with similar electronics provides an important toolbox for chemists to identify catalysts with improved ligand / substrate reactivity in catalysis.

[0387] The performance of MIC-IPr* catalysts in alkyne hydroamination was also evaluated (FIG. 18). This reaction also showed that (i) chloride-based [Au(MIC-IPr*)Cl] catalysts are superior catalysts to the iodide-based [Au(MIC-IPr*)I] catalysts, and (ii) there is a correlation between the steric impact of the catalyst and the reaction efficiency. Thus, the study between the sets of gold-chloride and gold-iodide ligands supported by 177-1,2,3- triazol-5-ylidenes revealed that steric bulk played a crucial role in increasing the yield of the hydroamination. For iodide-based catalysts 40a-40d, the yield increased from 7% to 27% in changing the catalyst 40a to 40d. Similarly, the yield improved by changing the catalyst to 41d. These results can be compared with the previous studies on the steric impact of IH- 1,2,3- triazol-5-ylidenes.

[0388] Another useful application of the unsymmetrical MIC-IPr* complexes is Au(I)- catalyzed arene / alkyne cycloisomerization (FIG. 19). This class of cyclizations has been performed mainly using gold-phosphine complexes. Pleasingly, it was found that different [Au(MIC-IPr*)Cl] catalysts in the presence of NaBArF4 at room temperature afforded the desired cycloisomerization product at a very low catalyst loading of 0.02 mol%. The observed steric trend of the catalysts was in line with the alkyne activation reactions (FIGs. 17-18), and the yield increased with increasing the steric bulk of catalysts. Example 10: DFT studies of unsymmetrical MIC-IPr* ligands

[0389] To further assess the electronic properties of the unsymmetrical MIC-IPr* ligands, HOMO and LUMO energy levels were determined at the B3LYP 6-311++g(d,p) level (FIGs. 20A-20B). It is now well-established that HOMO and LUMO energy levels provide the most accurate evaluation of nucleophilicity (e.g., more o-donatmg. higher HOMO) and electrophilicity (more 7i-accepting. lower LUMO) of NHC ligands.

[0390] The HOMO of MIC-IPr* / Ph (-5.73 eV) can be compared with the HOMO of MIC- IPr* / Mes (-5.61 eV) and the HOMO of MIC- IPr* / Dipp (-5.68 eV). Furthermore, the LUMO of MIC-IPr* / Ph (- 1.31 eV) can be compared with the LUMO of MIC-IPr* / Mes (- 1.12) and the LUMO of MIC-IPr* / Dipp (-1.17 eV). The n-donor orbital of MIC-IPr* / Ph (HOMO-1, - 6.23 eV) can be compared with the corresponding orbital for MIC-IPr* / Mes (HOMO-1, - 6.35 eV) and MIC-IPr* / Dipp (HOMO-1, -6.39 eV). These values indicate that the unsymmetrical I H- 1 .2.3-tri azol -5-ylidenes are significantly stronger o-donors than the classical imidazol-2- ylidenes, such as IPr (-6.01 eV) and IPr* (-6.12 eV), and more n- accepting than IPr (-0.48 ev) and IPr* (-0.90 eV), while the ^-donating orbital can be compared with IPr (-6.55 eV) and IPr* (- 6.28 eV). Electronically, the unsymmetrical MIC- IPr* ligands are similar in terms of o-donating and ^-accepting abi li ty.

[0391] Furthermore, to eliminate effects from crystal packing, the %percentage buried volume (%V&»r) was calculated from the optimized structures of [Au(MIC-IPr*)Cl] at the B3LYP 6- 311 ++g(d,p) level (FIGs. 21 A-21 F). These studies determined the %Vzw of the NHC in [Au(MIC- IPr* / Ph)Cl] as 35.9% (SW, 42.9%; NW, 41.6%; NE, 33.5%; SE, 25.6%); in [Au(MIC-IPr* / Mes)Cl] as 40.7% (SW, 52.4%; NW, 49.4%; NE, 32.0%; SE, 28.9%); in [Au(MIC-IPr* / Dipp)Cl] as 42.5% (SW. 48.5%; NW, 49.2%; NE, 34.6%; SE, 37.6%) (Fig. 6A- C). It is evident from the data that the percent buried volume (%V;>Mr) gradually increases from MIC-IPr* / Ph and MIC- IPr* / Mes to MIC-IPr* / Dipp (35.9%, 40.7% vs. 42.5%). Furthermore, there is a very7significant differentiation in SW / NW direction vs. NE / SE direction (A(avgsw NW- avgNE / SE) of MIC-IPr* / Ph = 12.7%; MIC-IPr* / Mes = 20.5%; MIC- IPr* / Dipp = 12.8%). These values can be compared with the symmetrical MIC-IPr* / IPr* of 44.9% (SW, 54.1%; NW, 43.3%; NE, 44.8%; SE, 37.4%) as well as with MIC-Mes of 31.8% (SW, 33.7%; NW, 33.7%; NE, 29.9%; SE, 29.9%) and MIC-IPr of 37.9% (SW, 39.1%; NW, 39.2%; NE, 36.7%; SE, 36.4%) (Fig. 6D-E). The symmetrical MIC-Mes and MIC-IPr are characterized by much smaller steric impact compared to the unsymmetrical MIC-IPr* / Mes and MIC-IPr* / Dipp (31.8% vs. 40.7% and 37.9% vs. 42.5%) as well as by the lack of steric differentiation between the SW / NW vs. NE / SE quadrants (A(avgsw / Nw - avgNE SE) of MIC- Mes = 3.8%; MIC-IPr = 2.6%).

[0392] Thus, the unsymmetrical MIC-IPr* provide a set of readily accessible by the ’click chemistry’ strongly o-donating NHC ligands with gradually differentiated overall sterics, but also these ligands are characterized by the unsymmetrical distribution of flexible steric hindrance that is highly useful from the catalysis standpoint.

[0393] Example 11: Exemplary Catalytic Reactions Using MIC-IPr*-MetaI Complexes

[0394] General Procedure: Au(I) -catalyzed intramolecular cyclization of acids

[0395] An oven-dried 10 mL reaction tube equipped with a stir bar was charged with y- alkynoic acid (98.1 mg, 1.0 mmol), Au-catalyst. and sodium tetrakis[3, 5- bis(trifluoromethyl)phenyl]borate. NaBAr' 4 as additive. After that, 0.5 mL of DCE was added to the mixture and was stirred at 50 °C for 12 h. The yield was determined by 'H NMR analysis. Analytical sample was isolated for characterization purposes. 5- Methylenedihydrofuran-2(3H)-one. (500 MHz, ) δ 4.C74DC (dId3, J = 4.5, 2.2 Hz, 1H), 4.31 (dd, J = 4.2, 1.9 Hz, 1H), 2.90 - 2.86 (m, 2H), 2.69 - 2.65 (m, 2H).13C NMR (126 MHz, CDCI3) 8 175.0, 155.8, 88.9, 28.1, 25.2. Conditions: pent-4-ynoic acid (1.0 equiv), [Au] 0.01-0.05 mol%, 2x mol% NaBAr' i. DCE, 50 °C, 12 h. Exemplary yields: [Au(MIC- IPr* / IPr*Me)I]: 98% (0.05 mol%); [Au(MIC-IPr* / IPr*Me)Cl] : 74% (0.01 mol%); [Au(MIC- IPr* / DippMe)Cl] : 70% (0.01 mol%); [Au(MIC-IPr* / MesMe)Cl] : 60% (0.01 mol%); [Au(IPr* / IPr*)Cl]: 25% (0.01 mol%).

[0396] General Procedure: Au(I)-catalyzed hydroamination

[0397] An oven-dried 10 mL reaction tube equipped with a stir bar was charged with phenylacetylene (102. 14 mg, 1.0 mmol), aniline (111.75 mg, 1.2 mmol), Au-catalyst, and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl] borate, NaBAr’ 4. The mixture was stirred at 50 °C for 12 h. The yield was determined by ’HNMR analysis. Analytical sample was isolated for characterization purposes. N,l-Diphenylethan-l-imine. (500 MHz, 1H NMR CDCh) δ 7.99 - 7.97 (m, 2H), 7.47 - 7.44 (m. 3H), 7.36 (t, J = 7.7 Hz, 2H), 7.09 (t, J = 7.4 Hz, 1H), 6.80 (d, J = 7.5 Hz, 2H), 2.24 (s, 3H).13C NMR (126 MHz, ) δ 165.6, 15C1.D9,CI3 139.6, 130.6, 129.1, 128.5, 127.3, 123.4, 119.5, 17.52. Conditions: alkyne (1.2 equiv), aniline (1.0 equiv), [Au] 0.05 mol%, 2x mol% NaBAr’ r. 50 °C, 12 h. Exemplary yields: [Au(MIC- IPr* / IPr*Me)Cl]: 84%; [Au(MIC-IPr* / DippMe)Cl]: 53%; [Au(MIC-IPr* / MesMe)Cl] : 50%; [Au(IPr* / IPr*)Cl]: 54%.

[0398] General Procedure: Au(I)-catalyzed cycloisomerization of amides

[0399] An oven-dried 10 mL reaction tube equipped with a stir bar was charged with N- (prop-2-yn-l-yl)benzamide (159.2 mg, 1.0 mmol), Au-catalyst, and silver triflate (AgOTf) as additive. After that, 1.0 mL of DCE was added to the mixture and was stirred at 50 °C for 12 h. The yield was determined by an1Hal NysMisR. Analytical sample was isolated for characterization purposes. 5-Methylene-2-phenyl-4.5-dihydrooxazole.1H NMR (500 MHz, CDCh) δ 7.97 (d, J = 8.6 Hz, 2H), 7.53 - 7.49 (m, 1H), 7.45 - 7.42 (m, 2H), 4.81 (q, J = 3.0 Hz, 1H), 4.65 (t, J = 2.8 Hz, 2H), 4.36 (q, J = 2.7 Hz, 1H).13C NMR (126 MHz, ) δ CDCI3 163.8, 159.0, 131.9, 128.6, 128.1, 126.9, 83.9. 57.9. Conditions: amide (1.0 equiv), [Au] (0.02-0.01 mol%), AgOTf (2x mol%). DCE, 50 °C, 12 h. Exemplary yields: [Au(MIC- IPr* / IPr*Me)Cl]: 99% (0.02 mol%); [Au(MIC-IPr* / IPr*Me)Cl]: 73% (0.01 mol%); and [Au(IPr* / IPr*)Cl] : 54% (0.01 mol%).

[0400] An oven-dried 10 mL reaction tube equipped with a stir bar was charged with phenyl propargyl ether (66. 1 mg, 0.5 mmol), Au-catalyst. and NaBAr’ r as an additive. After that, 0.5 mL of DCM was added to the mixture and stirred at room temperature for 12 h. The yield was determined by1H NMR analysis. Analytical sample was isolated for characterization purposes. 2H-Chromene. 1H (5 N0M0 MRHz, ) δ 7.1C1D (tCdI,3 J = 7.8, 1.6 Hz, 1H), 6.97 (dd, J = 7.4, 1.6 Hz, 1H), 6.87 (td, J = 7.4, 1.0 Hz, 1H), 6.79 (d, J = 8.0 Hz, 1H), 6.43 (d, J = 9.8 Hz. 1H), 5.77 (dt, J = 9.8, 3.6 Hz, 1H), 4.83 (dd, J = 3.5, 1.9 Hz, 2H).13C NMR (126 MHz, CDCI3) δ 154.2, 129.2, 126.7, 124.7, 122.5, 122.1, 121.4, 115.8, 65.6. Conditions: alkyne (1.0 equiv), [Au] (0.02 mol%), 0.2 mol% NaBAiTi, DCE, 23 °C, 12 h. Exemplar}7yields: [Au(MIC-IPr* / IPr*Me)Cl]: 99% (0.05 mol%); [Au(MIC-IPr* / IPr*Me)Cl] : 80% (0.02 mol%): [Au(MIC-IPr* / DippMe)Cl]: 66% (0.02 mol%); [Au(MIC-IPr* / MesMe)Cl]: 54% (0.02 mol%).

[0401] General Procedure: Au(I) -catalyzed alkyne, alkene coupling

[0402] An oven-dried 10 mL reaction tube equipped with a stir bar was charged with phenyl acetylene (255 mg. 2.5 mmol), a-methyl styrene (591 mg, 5 mmol), Au-catalyst, and NaBArF4 as additive. The mixture was stirred at room temperature for 2 days. The yield was determined by1H NMR analysis. Analytical sample was isolated for characterization purposes. (3-Methylcyclobut-l-ene-l,3-diyl)dibenzene. (500 M1HHz N, MR ) δ 7.42 - CDCI3 7.40 (m, 4H), 7.36 - 7.32 (m, 4H). 7.28 (s, 1H), 7.20 (t, J = 6.8 Hz, 1H), 6.74 (s, 1H), 3.00 - 2.92 (m, 1H), 1.65 (s, 3H).13C NMR (126 MHz, ) δ 147C.8D5,C 1I433.98. 134.87. 133.89, 128.46, 128.27, 127.94, 126.00, 125.82, 124.74, 77.41, 77.16, 76.91, 46.12, 44.42, 27.71. Conditions: alkyne (1.0 equiv), alkene (2 equiv), [Au] (0.3 mol%), 2x mol% NaBArF4, DCE, 23 °C, 48 h. Exemplar}7yield: [Au(MIC-IPr* / IPr*Me)Cl]: 90%.

[0403] General Procedure: Cu-catalyzed hydration of alkynes

[0404] An oven-dried 10 mL reaction tube equipped with a stir bar was charged with phenylacetylene (102.14 mg, 1.0 mmol), aniline (14 mg, 0.15 mmol). Cu-catalyst (0.025 mmol, 2.5 mol%), and sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate, NaBA^ (0.0375 mmol, 3.75 mol%), as additive. The mixture was stirred at 120 °C for 18 h. The crude mixture was directly loaded in the column and purified by silica gel column chromatography using petroleum ethyl acetate / hexane (1 / 20) as the eluent. Acetophenone. 'H NMR (500 MHz, CDC)I δ3 7.93 (d, J = 8.4 Hz, 2H), 7.54 (t, J = 7.4 Hz, 1H), 7.44 (t, J = 7.9 Hz, 2H), 2.58 (s, 3H).13C NMR (126 MHz, ) δ 19C8D.1C, I 1337.2, 133.1, 128.6, 128.3, 26.6.

[0405] Conditions: alkyne (1.0 equiv), aniline (15 mol%), [Cu] 2.5 mol%, 2x mol% NaBAr -i. water, 120 °C, 20 h. Exemplary yield: [Cu(MIC-IPr* / MesMe)Cl]: 71%.

[0406] General Procedure: Cu-catalyzed hydrosilylation of ketones

[0407] A 10 mL Schlenk tube containing a stirring bar was charged with Cu-catalyst (0.001 mmol, 1.0 mol%), NaOtBu (0.002 mmol, 2.0 mol%) and toluene (1.5 mL). The mixture was sealed with a cap (phenolic open-top cap with red PTFE / white silicone septum) and allowed to stir for 10 min. After this time, the toluene solution (0.5 mL) of acetophenone derivatives (0.4 mmol, 1.0 equiv) and tri ethoxy silane (1.2 mmol, 3.0 equiv) were added (syringe). The mixture was then stirred at 60 °C for 12 h. After that, the crude mixture was concentrated in vacuo and was purified by silica gel chromatography (ethyl acetate: hexane = 1 :50) to afford the hydrosilylated product. l-(4-Chlorophenyl)ethyl triethyl silicate. (500 MHz, 1H NMR CDCh) δ 7.30 - 7.22 (m, 4H). 5.07 (q, J = 6.4 Hz, 1H). 3.80 - 7.74 (m. 6H), 1.46 (d. J = 6.4 Hz, 3H), 1.17 (t, J = 7.0 Hz, 9H).13C NMR (126 MHz, ) δ 144.3C, D 13C2I.38, 128.5, 126.9, 70.8, 59.4, 26.36, 18.2. Conditions: ketone (1.0 equiv; e.g.. 4-chloroacetophenone), (EtOSihSiH (3 equiv), [Cu] (0.1 mol%), NaOtBu (2x mol%). toluene, 60 °C, 12 h. Exemplary yields: [Cu(MIC-IPr* / DippMe)Cl]: 99% (1.0 mol%); [Cu(MIC-IPr* / Dippxle)Cl]: 94% (0.1 mol%); [Cu(IPr)Cl]: 76% (0.1 mol%).

[0408] General Procedure: Cu-catalyzed borylation of alkenes

[0409] A 10 mL Schlenk tube containing a stirring bar was charged Cu-catalyst (0.01 mmol, 5.0 mol%). NaOtBu (0.0100 mmol, 5.0 mol%) and tetrahydrofuran (0.3 mL). The mixture was sealed with a cap (phenolic open-top cap with red PTFE / white silicone septum) and allowed to stir for 10 min. Bis(pinacolato)diboron (53.3 mg, 0.21 mmol, 1.05 equiv) was added to the solution and the solution turned dark brown immediately. The mixture was allowed to stir at rt for 15 min under an atmosphere of N2. After this time, the THF solution (0.2 mL) of styrene derivatives (0.20 mmol. 1.0 equiv) and MeOH (8.9 pL. 0.220 mmol. 1.1 equiv) were added and stirred for 12 h at 60 °C After that, the crude mixture was concentrated in vacuo and was purified by silica gel chromatography (ethyl acetate: hexane = 1:20) to afford the product. 2-(4-Methoxyphenethyl)-4,4,5,5-tetramethyl-1.3.2-dioxaborolane. 'H NMR (500 MHz, CD)C δI37.1 1 (d, J = 8.5 Hz, 2H), 6.79 (d, J = 8.6 Hz, 2H), 3.76 (s, 3H), 2.67 (d, J = 8.2 Hz, 2H), 1.20 (s, 12H), 1.09 (d, J = 8.2 Hz, 2H). Conditions: alkene (1.0 equiv), B2pin2 (1.05 equiv), [Cu] (2-5 mol%), NaOtBu (5 mol%), MeOH (1.1 equiv), THF, 23-60 °C, 12 h. Exemplary yields: [Cu(MIC-IPr* / MesMe)Cl] : 79% (2 mol%, 60 °C), and [Cu(MIC-IPr* / DippMe)Cl]: 30% (2 mol%. 60 °C) (4-methoxy styrene).

[0410] General Procedure: Cu-catalyzed borylation of alkynes

[0411] A 10 mL Schlenk tube containing a stirring bar was charged Cu-catalyst (0.01 mmol, 5.0 mol%), NaOtBu (0.0100 mmol, 5.0 mol%) and tetrahydrofuran (0.3 mL). The mixture was sealed with a cap (phenolic open-top cap with red PTFE / white silicone septum) and allowed to stir for 10 min. Bis(pinacolato)diboron (53.3 mg, 0.21 mmol, 1.05 equiv) was added to the solution and the solution turned to dark brown immediately. The mixture was allowed to stir at rt for 15 min under an atmosphere of N2. After this time, the THF solution (0.2 mL) of terminal derivatives (0.20 mmol, 1.0 equiv) and MeOH (8.9 pL, 0.220 mmol, 1.1 equiv) were added (syringe). The mixture was then stirred at 60 °C for 12 h. After that, the crude mixture was concentrated in vacuo and was purified by silica gel chromatography (ethyl acetate:hexane = 1 :20) to afford the product. One representative example is shown for aromatic and aliphatic terminal alkyne. (E)-4,4,5,5-Tetramethyl-2-styryl-l,3,2-dioxaborolane. ’H NMR (500 MHz, CD)C δI37.49 (d, J = 7.2 Hz, 2H), 7.41 (d, J = 18.4 Hz, 1H), 7.34 (t, J = 7.3 Hz. 2H), 7.30 - 7.27 (m, 1H), 6. 18 (d, J = 18.4 Hz, 1H). 1.32 (s, 12H).13C NMR (126 MHz, CDCI3) δ 149.5, 137.5, 128.9, 128.6, 127.1, 83.3, 24.8. (E)-4,4,5,5-Tetramethyl-2-(5- phenylpent-l-en-l-yl)-l,3,2-dioxaborolane. 'H NMR (500 MHz, ) δ 7.28 -CD 7.C25I3 (m, 2H), 7.18 - 7.16 (m, 3H), 6.65 (dt, J = 18.0, 6.4 Hz, 1H), 5.46 (dt, J = 18.0, 1.6 Hz, 1H), 2.62 (2.62 (d, J = 7.8 Hz, 2H)), 2.22 - 2,17 (m, 2H), 1.76 (dt, J = 15.0, 7.6 Hz. 2H), 1.27 (s, 12H).13C NMR (126 MHz, C)D δC 1I534.2. 142.5, 128.6. 128.4, 125.8. 83.2. 35.5. 35.4. 29.9, 24.9. Conditions: alkyne (1.0 equiv), B2pin2 (1.05 equiv), [Cu] (2-5 mol%), NaOtBu (5 mol%), MeOH (1.1 equiv), THF, 23-60 °C, 12 h. Exemplary yields: [Cu(MIC-IPr* / DippMe)Cl]: 64% (5 mol%, 23 °C) (pent-4-yn-l-ylbenzene).

[0412] General Procedure: Cu-catalyzed reduction of alkynes to alkenes

[0413] A 10 mL Schlenk tube containing a stirring bar was charged with Cu-catalyst (0.040 mmol, 0.0015 mol%) and tBuONa (0.045 mmol, 15 mol%) and THF(1.0 mL). The mixture was stirred for 15 min at room temperature under the N2-atmosphere. The terminal alkyne (0.3 mmol, 1 equiv.) in hexane (1.0 mL), PMHS (1.2 mmol as the SiH unit, 4.0 equiv.) and tBuOH (0.6 mmol. 2.0 equiv.) were added consecutively. The resulting mixture was stirred at 45 °C for 12 h. After the reaction, the pure product was isolated by silica gel column chromatography with pentane as an eluent. l-Methoxy-4-vinylbenzene. (500 MHz, 1H NMR CDCh) 8 7.37 (d, J = 8.8 Hz, 2H), 6.88 (d, J = 8.8 Hz, 2H), 6.69 (dd, J = 17.6, 10.9 Hz, 1H), 5.63 (dd, J = 17.6, 0.9 Hz, 1H), 5. 15 (dd, J = 10.9. 0.9 Hz, 1H), 3.82 (s, 3H).13C NMR (126 MHz, CDCI3) 6 159.4. 136.3, 130.5. 127.4, 114.0. 111.6, 55.3. Conditions: alkyne (1.0 equiv), PMHS (4 equiv), [Cu] (0.5 mol%), NaOtBu (15 mol%), THF / hexane, 45 °C, 12 h. Exemplary yield: [Cu(MIC-IPr* / DippMe)Cl]: 68% (0.5 mol%); (4-methoxyphenylacetylene).

[0414] General Procedure: Cu-catalyzed oxidation of alcohols to carboxylic acids

[0415] A 10 mL reaction tube containing a stirring bar was charged with Cu-catalyst (0.004 mmol, 2 mol %) and potassium tert-butoxide (0.4 mmol, 2 equiv) and distilled THF (1 mL) was added to the vessel. Then, oxygen was gently bubbled for 5 minutes and later, an oxygen balloon was attached to it. Benzyl alcohol (0.2 mmol, 1 equiv) was added and the reaction vessel was sealed and stirred for 12 h under an oxygen balloon. After this, the reaction mixture was washed with ethyl acetate and 5 mL of 0.1 m HC1 was added. The aqueous phase was then extracted with ethyl acetate and the combined organic phase was dried over anhydrous sodium sulfate and evaporated in vacuo to obtain the carboxylic acid product. Benzoic acid. 1H NM (5R00 MHz, ) C δD 12C.I531 (s, 1H), 8.14 (d, J = 7.5 Hz, 2H), 7.63 (t, J = 7.4 Hz, 1H), 7.49 (t, J = 7.8 Hz, 2H).13C NMR (126 MHz, ) δ 172.4, 1C3D4.C0,I3130.4, 129.5, 128.7.

[0416] General Procedure: C u-catalyzed oxidation of aldehydes to carboxylic acids

[0417] A 10 mL reaction tube containing a stirring bar was charged with Cu-catalyst (0.004 mmol, 2 mol %) and sodium hydroxide (0.2 mmol, 1 equiv) and distilled water (1 mL) was added to the vessel. Then, oxygen was gently bubbled for 5 minutes and later, an oxygen balloon was attached to it. The reaction mixture was then warmed up to 50 °C before the aldehyde (0.2 mmol. 1 equiv) was added. The reaction vessel was then sealed and kept at 50 °C for 12 h. After this, the reaction mixture was washed with ethyl acetate and 5 mL of 0. 1 m HC1 was added. The aqueous phase was then extracted with ethyl acetate and the combined organic phase was dried over anhydrous sodium sulfate and evaporated in vacuo to obtain the carboxylic acid product. 4-Methoxybenzoic acid.rH NMR (500 MHz, ) δ 8.04 (d. J =CDCI3 8.7 Hz, 2H), 6.93 (d, J = 8.7 Hz, 2H), 3.86 (s, 3H). Conditions: alcohol (1.0 equiv), O2, KOtBu (2 equiv), [Cu] (2 mol%), THF, 23 °C, 12 h. Exemplary yields: [Cu(MIC- IPr* / MesMe)I] : 65% (2.0 mol%); [Cu(IPr)Cl]: <10% (2.0 mol%).

[0418] General Procedure: Pd-catalyzed Buchwald-Hartwig amination

[0419] A 10 mL Schlenk tube containing a stirring bar was charged with an aryl chlorides (0.5 mmol, 1 equiv), amine (0.6 mmol, 1.2 equiv), sodium tert-butoxide (0.6 mmol, 1 equiv), Pd-catalyst ( (0.01 mmol, 2 mol%), and 4 mL of dry DME was added to it. The reaction stirred at room temperature under N2 atmosphere for 16 h. After completion of the reaction, the crude mixture was directly loaded in the column and purified by silica gel column chromatography using petroleum ethyl acetate / hexane (1 / 5) as the eluent. N-(Furan-2- ylmethyl)thiazol-2-amine.JH NMR (500 MHz, ) δ 7.3C6D (dC,I3 J = 2.5 Hz, 1H), 7.08 (d, J = 3.6 Hz. 1H), 6.48 (d, J = 3.6 Hz, 1H), 6.32 - 6.31 (m, 1H), 6.29 - 6.28 (m, 1H), 6. 15 (s, 1H), 4.46 (s, 2H). Conditions: ArCl (1 equiv). amine (1.2 equiv), [Pd] 2 mol%. NaOtBu (1.2 equiv), DME, 23 °C, 16 h. Exemplary yields: [Pd(MIC-IPr* / IPr*Me)(cin)Cl]: 88% (2 mol%); [Pd(IPr*)(cin)Cl]: 59% (2 mol%).

[0420] General Procedure: Pd-catalyzed Wacker oxidation of olefins

[0421] A 10 mL Schlenk tube containing a stirring bar was charged styrene derivatives (0.4 mmol, 1 equiv) and TBHP (dec) (1.2 mmol, 1 equiv) were sequentially added to a dry acetonitrile solution of the Pd-catalyst (0.02 mmol, 5 mol%). The mixture was stirred at 50 °C for 12 h. Then, the crude was purified by column chromatography on silica gel petroleum ether / EtOAc to give the corresponding product. One representative example is shown below. l-(4-Methoxyphenyl)ethan-l-one. ‘H NMR (500 MHz, ) δ 7.91C (dD,C JI =3 9.0 Hz, 2H), 6.91 (d, J = 8.7 Hz, 2H), 3.84 (s, 3H), 2.53 (s, 3H).13C NMR (126 MHz, ) δ 196.7, CDCI3 163.5, 130.6, 130.4, 113.7, 55.4, 26.3. Conditions: alkene (1.0 equiv), [Pd] 5 mol%, tBuOOH (3 equiv), CH3CN, 50 °C, 12 h. Exemplar)’ yield: [Pd(MIC-IPr* / IPr*Me)(cin)Cl]: 33% (5 mol%) (4-methoxystyrene).

[0422] General Procedure: Ir- and Rh-catalyzed hydrogenation of arenes

[0423] A 10 mL reaction tube containing a stirring bar was charged with the 2,3 benzofuran (0.2 mmol), Ir- or Rh-catalyst and DCE (1 mL). The reaction mixture was stirred at room temperature for 12 h under H2 (50 bar). The crude mixture was passed through celite filtration and evaporated under reduced pressure. The crude product was purified by silica gel chromatography (ethyl acetate:hexane = 1: 100) to afford the product. 2,3 -Dihydrobenzofuran. 1H NMR (500 MHz, CD)C δI37.20 (d, J = 7.2 Hz, 1H), 7. 11 (t, J = 7.7 Hz, 1H), 6.84 (t, J = 7.4 Hz. 1H), 6.79 (d. J = 8.0 Hz. 1H), 4.56 (t, J = 8.7 Hz, 2H), 3.21 (t, J = 8.7 Hz, 2H). 1,2,3,4-Tetrahydroquinoline. (15H00 N MMHRz, ) δ 6.98C -D 6C.9I43 (m, 2H), 6.61 (t, J = 7.4 Hz, 1H), 6.47 (d, J = 7.9 Hz, 1H), 3.82 (s, 1H), 3.31 - 3.29 (m, 2H), 2.77 (t, J = 6.4 Hz, 2H), 1.97 - 1.92 (m, 2H). Conditions (Ir-catalyzed hydrogenation, quinoline): quinoline (1.0 equiv), [Ir] (3 mol%), H2 (50 atm), DCE, 50 °C, 12 h. Exemplary yield: [Ir(MIC- IPr* / MesMe)(cod)Cl]: 99% (3 mol%). Conditions (Ir-catalyzed hydrogenation, benzofuran): benzofuran(1.0 equiv), [Ir] (1 mol%), H2 (50 atm), DCE, 23 °C, 12 h. Exemplary yield: [Ir(MIC-IPr* / DippMe)(cod)Cl] : 90% (1 mol%). Conditions (Rh-catalyzed hydrogenation, 1- methoxy-4-fluorobenzene): arene (1.0 equiv). [Rh] 3 mol%, H2(35 atm). SiCh. DCE, 50 °C, 12 h. Exemplary yield: [Rh(MIC-IPr* / MesMe)(cod)Cl] : 46% (3 mol%). Conditions (Rh- catalyzed hydrogenation, 4-methoxy phenol): arene (1.0 equiv), [Rh] 3 mol%, H2 (35 atm), TFE / H2O, 40 °C, 12 h. Exemplary yield: [Rh(MIC-IPr* / MesMe)(cod)Cl]: 20% (3 mol%).

[0424] General Procedure: Cu-catalyzed cyclization of carboxylic acids

[0425] An oven-dried 10 mL reaction tube equipped with a stir bar was charged with y- alkynoic acid (98.1 mg, 1.0 mmol) and Cu-catalyst. After that, 0.5 mL of DCE was added to the mixture and was stirred at 50 °C for 12 h. The yield was determined by1H NMR analysis. Conditions: pent-4-ynoic acid (1.0 equiv), [Cu] 0.01-1.0 mol%. DCE, 50 °C, 12 h. Exemplary yields: [Cu(MIC-IPr* / DippMe)Cl]: 97% (1.0 mol%); [Cu(MIC-IPr* / DippMe)Cl] : 70% (0.01 mol%); [Cu(IPr)Cl]: <10% (0.01 mol%). lalyzed hydroboration of alkynes conditions

[0426] A 10 mL Schlenk tube containing a stirring bar was charged Ag-catalyst (0.006 mmol, 3.0 mol%), NaOtBu (0.018 mmol, 9.0 mol%) and tetrahydrofuran (0.3 mL). The mixture was sealed with a cap (phenolic open-top cap with red PTFE / white silicone septum) and allowed to stir for 10 min. Bis(pinacolato)diboron (53.3 mg, 0.21 mmol, 1.05 equiv) was added to the solution and the solution turned to dark brown immediately. The mixture was allow ed to stir at rt for 15 min under an atmosphere of N2. After this time, the THF solution (0.2 mL) of terminal derivatives (0.20 mmol, 1.0 equiv) and MeOH (8.9 pL, 0.220 mmol, 1.1 equiv) were added (syringe). The mixture was then stirred at 50 °C for 12 h. After that, the crude mixture was concentrated in vacuo and was purified by silica gel chromatography (ethyl acetate: hexane = 1:20) to afford the product. One representative example is shown for aromatic and aliphatic terminal alkyne. (E)-4,4,5,5-Tetramethyl-2-styryl-1.3.2-dioxaborolane. Conditions: alkyne (1.0 equiv), B2pin2 (1.0 equiv), [Ag] (3 mol%), KOtBu (9 mol%), MeOH, 50 °C, 12 h. Exemplary yields: [Ag(MIC-IPr* / PhMe)I]: 67%; [Cu(MIC-IPr* / PhMe)Cl]: 54%.

[0427] Enumerated Embodiments

[0428] The following exemplary embodiments are provided, the numbering of which is not to be construed as designating levels of importance:

[0429] Embodiment 1 provides a compound of formula (I): wherein:

[0430] R1and R2are each independently selected from the group consisting of optionally substituted C6-C10 aryl, optionally substituted C2-C8 heteroaryl, optionally substituted C3-C8 cycloalkyl, or C2-C8 heterocycloalkyl, wherein at least one C6-C10 aryl or C2-C8 heteroaryl of R1or R2, if present, is substituted at one or two ortho positions thereof with -CH(optionally substituted C6-C10 aryl)2, and wherein at least one C3-C8 cycloalkyl or C2-C8 heterocycloalkyl of R1or R2, if present, comprises a quaternary' carbon atom;

[0431] R3is selected from the group consisting of optionally substituted C1-C6 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C2-C8 heterocycloalkyl, optionally substituted C6-C10 aryl, and optionally substituted C2-C8 heteroaryl:

[0432] X1is a monovalent counter anion; each occurrence of optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, and optionally substituted heteroaryl, is independently optionally substituted with at least one selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, CN, NO2, ORA, N(RA)(RB), C(=O)RA, C(=O)N(RA)(RB), C(=O)ORB, N(RA)S(=O)2RB, S(=O)2N(RA), C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl. C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyl, wherein the C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzy l are each optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyd. C2-C6 alkenyl, benzyl, phenyl, naphthyl, and pyridyl; and

[0433] RAand RBare each independently selected from the group consisting of H, C1-C6 alky l, C1-C3 haloalkyl, C2-C6 alkenyl, benzyl, naphthyl, C4-C10 heteroaryl, and phenyl, wherein each substituent in RAand RBis optionally substituted with at least one substituent selected from the group consisting of CN. NO2, C1-C3 haloalkyl, C1-C3 alkoxy. C1-C3 haloalkoxy, C1-C3 alky l, and halogen.

[0434] Embodiment 2 provides the compound of Embodiment 1, wherein R1is: wherein:

[0435] Rla. Rlb, Rlc, Rld, and Rleare each independently selected from the group consisting of H. halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of Rla, Rlb, Rlc, Rld, and Rleis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0436] Embodiment 3 provides the compound of Embodiment 2, wherein Rla, Rlb, Rlc, Rld, and Rleare each independently selected from the group consisting of H, methyl, isopropyl, and diphenylmethy l.

[0437] Embodiment 4 provides the compound of Embodiment 2 or 3, wherein at least one of the following applies:

[0438] (a) Rlband Rldare independently H;

[0439] (b) Rlb, Rlc, and Rldare each independently H;

[0440] (c) Rlaand Rleare identical; and

[0441] (d) Rla. Rlc, and Rlcare identical.

[0442] Embodiment 5 provides the compound of any one of Embodiments 2-4, wherein one of the following applies:

[0443] (a) Rlaand Rleare each independently optionally substituted C1-C6 alky l, and Rlb, Rlc. and Rldare H; and

[0444] (b) Rla, Rlc, andRleare each independently optionally substituted C1-C6 alkyl. and Rlband Rldare H.

[0445] Embodiment 6 provides the compound of any one of Embodiments 1-5, wherein R1is selected from the group consisting of:

[0446] Embodiment 7 provides the compound of any one of Embodiments 1-6, wherein R2 tly selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of R2a, R2b, R2c, R2d, and R2eis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0447] Embodiment 8 provides the compound of Embodiment 7, wherein R2a, R2b, R2c, R2d, and R2eare each independently selected from the group consisting of H, methyl, isopropyl, and diphenylmethyl.

[0448] Embodiment 9 provides the compound of Embodiment 7 or 8, wherein:

[0449] (a) R2a, R2b, R2C, R2d, and R2eare each independently H;

[0450] (b) R2band R2dare independently H;

[0451] (b) R2b. R2C, and R2dare each independently H;

[0452] (c) R2aand R2eare identical; and

[0453] (d) R2a, R2C, and R2eare identical.

[0454] Embodiment 10 provides the compound of any one of Embodiments 7-9, wherein one of the following applies:

[0455] (a) R2aand R2Bare each independently optionally substituted C1-C6 alkyl, and R2b,

[0456] R2C, and R2dare H; and (b) R2a, R2®, andR2® are each independently optionally substituted C1-C6 alkyl, and R2band R2dare H.

[0457] Embodiment 11 provides the compound of any one of Embodiments 1-10, wherein R2is selected from the group consisting of

[0458] Embodiment 12 provides the compound of any one of Embodiments 1-11, wherein one of the following applies:

[0459] Embodiment 13 provides the compound of any one of Embodiments 1-12, wherein R3is selected from the group consisting of methyl, isopropyl, phenyl, and 2,6-diisopropylphenyl. Embodiment 14 provides the compound of any one of Embodiments 1-13, wherein X1is selected from the group consisting of halogen, OS(=O)2RA. OC(=O)RA, N(C(=O)RA)2, tetracoordinate boronate, and hexacoordinate phosphorus, optionally wherein X1is selected from the group consisting of I, BF4, and PFe. Embodiment 15 provides the compound of any one of Embodiments 1-14, which is selected from the group consisting of:

[0460] Embodiment 16 provides a compound of formula (II): wherein: M is a transition metal;

[0461] R1and R2are each independently selected from the group consisting of optionally substituted C6-C10 aryl, optionally substituted C2-C8 heteroaryl, optionally substituted C3-C8 cycloalkyl, or C2-C8 heterocycloalkyl, wherein at least one C6-C10 aryl or C2-C8 heteroaryl of R1or R2, if present, is substituted at one or two ortho positions thereof with -CH(optionally substituted C6-C10 aryl)2. and wherein at least one C3-C8 cycloalkyl or C2-C8 heterocycloalkyl of R1or R2, if present, comprises a quaternary carbon atom;

[0462] R3is selected from the group consisting of optionally substituted C1-C6 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C2-C8 heterocycloalkyl, optionally substituted C6-C10 aryl, and optionally substituted C2-C8 heteroaryl;

[0463] L is a ligand of M, wherein each occurrence of L can be the same or different;

[0464] X2is a monovalent or divalent counter anion, wherein L and X2can be present in a single compound; each occurrence of optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, and optionally substituted heteroaryl. is independently optionally substituted with at least one selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, CN. NO2, ORA. N(RA)(RB). C(=O)RA, C(=O)N(RA)(RD), C(=O)ORD, N(RA)S(=O)2RB, S(=O)2N(RA), C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyd, wherein the C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyl are each optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alky l, C2-C6 alkenyl, benzy l, phenyl, naphthyl, and pyridyl;

[0465] RAand RBare each independently selected from the group consisting of H, C1-C6 alkyl, C1-C3 haloalkyl. C2-C6 alkenyl, benzyl, naphthyl. C4-C10 heteroaryl, and phenyl, wherein each substituent in RAand RBis optionally substituted with at least one substituent selected from the group consisting of CN, NO2, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, and halogen; m is an integer which is selected from the group consisting of 0. 1, 2, and 3; and n is an integer which is selected from the group consisting of 0, 1, and 2. Embodiment 17 provides the compound of Embodiment 16. wherein R1is: wherein:

[0466] Rla. Rlb, Rlc, Rld, and Rlcare each independently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of Rla, Rlb, Rlc, Rld, and Rleis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0467] Embodiment 18 provides the compound of Embodiment 17, wherein Rla, Rlb, Rlc, Rld, and Rleare each independently selected from the group consisting of H, methyl, isopropyl, and diphenylmethyl.

[0468] Embodiment 19 provides the compound of Embodiment 17 or 18, wherein at least one of the following applies:

[0469] (a) Rlband Rldare independently H;

[0470] (b) Rlb, R1c, and Rldare each independently H;

[0471] (c) Rlaand Rleare identical; and

[0472] (d) Rla, Rlc, and Rleare identical.

[0473] Embodiment 20 provides the compound of any one of Embodiments 17-19, wherein one of the following applies:

[0474] (a) Rlaand Rleare each independently optionally substituted C1-C6 alkyl, and Rlb, Rlc, and Rldare H; and

[0475] (b) Rla, Rlc, andRleare each independently optionally substituted C1-C6 alkyl, and Rlband Rldare H.

[0476] Embodiment 21 provides the compound of any one of Embodiments 16-20, wherein R1is selected from the group consisting of: Embodiment 22 provides the compound of any one of Embodiments 16-2L wherein

[0477] R2is: wherein:

[0478] R2aj^2b j^2c in(jepen(jently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of R2a, R2b, R2c, R2d, and R2eis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

[0479] Embodiment 23 provides the compound of Embodiment 22, wherein R2a, R2b, R2c, R2d, and R2eare each independently selected from the group consisting of H, methyl, isopropyl, and diphenylmethyl.

[0480] Embodiment 24 provides the compound of Embodiment 22 or 23, wherein:

[0481] (a) R2a, R2b, R2C, R2d, and R2eare each independently H;

[0482] (b) R2band R2dare independently H;

[0483] (b) R2b. R2C, and R2dare each independently H;

[0484] (c) R2aand R2eare identical; and

[0485] (d) R2a, R2C, and R2eare identical.

[0486] Embodiment 25 provides the compound of any one of Embodiments 22-24, wherein one of the following applies:

[0487] (a) R2aand R2Bare each independently optionally substituted C1-C6 alkyl, and R2b, R2C, and R2dare H; and

[0488] (b) R2a, R2C, andR2® are each independently optionally substituted C1-C6 alkyl, and R2band R2dare H.

[0489] Embodiment 26 provides the compound of any one of Embodiments 16-25, wherein R2is selected from the group consisting of:

[0490]

[0491] Embodiment 28 provides the compound of any one of Embodiments 16-27, wherein R3is selected from the group consisting of methyl, isopropyl, phenyl, and 2,6- diisopropylphenyl.

[0492] Embodiment 29 provides the compound of any one of Embodiments 16-28, wherein M is selected from the group consisting of Pd. Cu, Ag, Au, Ni, Pt, Co, Rh, Ir. Fe. Ru, and Os

[0493] Embodiment 30 provides the compound of any one of Embodiments 16-29, wherein M is selected from the group consisting of Au, Ag, Cu, Pd, Ir, and Rh.

[0494] Embodiment 31 provides the compound of any one of Embodiments 16-30. wherein each L is independently selected from the group consisting of carbon monoxide (CO), optionally substituted C2-C12 alkene, and optionally substituted C5-C12 cycloalkene, optionally substituted benzylamine, optionally substituted C2-C8 hctcroaryl. wherein each optional substituent in the C2-C12 alkene, C5-C12 cycloalkene, benzylamine, and C2-C8 heteroaryl is independently selected from the group consisting of a halogen, CN. NO2. C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C3-C8 cycloalkyl, phenyl, and C2-C8 heterocyclyl.

[0495] Embodiment 32 provides the compound of any one of Embodiments 16-31, wherein each L is independently selected from the group consisting of carbon monoxide (CO), cyclooctadiene (COD), and (1-phenylpropenide and l-phenylprop-2-en-l-ide; double bond thereof).

[0496] Embodiment 33 provides the compound of any one of Embodiments 16-32, wherein each X2is independently selected from the group consisting of halogen, OS(=O)2RA. OC(=O)RA, N(C(=O)RA)2, optionally substituted allyl anion, tetracoordinate boronate, and hexacoordinate phosphorus, optionally wherein each X2is independently selected from the group consisting of Cl, I, and (1-phenylpropenide and l-phenylprop-2-en-l- ide; anion thereof).

[0497] Embodiment 34 provides the compound of any one of Embodiments 16-33, which is selected from the group consisting of:

[0498] ([Pd(MIC-IPr* / IPr*Me)(cin)I]),

[0499]

[0500]

[0501] Embodiment 35 provides a method of promoting an intramolecular cyclization of a compound comprising a terminal alkyne and a carboxylic acid, the method comprising contacting the compound comprising the terminal alkyne and the carboxylic acid with at least one compound of any one of Embodiments 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is sodium tetrakis[3,5- bis(trifluoromethyl)phenyl]borate (NaBArF4), and optionally wherein M is Au or Cu.

[0502] Embodiment 36 provides a method of promoting a reaction betw een an alky ne and an aniline, the method comprising contacting the alkyne and the aniline with at least one compound of any one of Embodiments 16-34. optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBAriri, and optionally wherein M is Au.

[0503] Embodiment 37 provides a method of promoting an intramolecular cyclization of a compound comprising a propargyl amide, the method comprising contacting the propargyl amide with at least one compound of any one of Embodiments 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally w herein the Lewis acid is AgOTf, and optionally wherein M is Au.

[0504] Embodiment 38 provides a method of promoting a reaction between an alkyne and an arene, the method comprising contacting the alkyne and the arene with at least one compound of any one of Embodiments 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

[0505] Embodiment 39 provides a method of promoting a reaction between an alkyne and an alkene, the method comprising contacting the alkyne and the alkene with at least one compound of any one of Embodiments 16-34, optionally w herein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

[0506] Embodiment 40 provides a method of promoting hydration of an alkyne, the method comprising contacting the alkyne and an aniline with at least one compound of any one of Embodiments 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4. and optionally wherein M is Cu.

[0507] Embodiment 41 provides a method of promoting hydrosilylation of a ketone, the method comprising contacting the ketone and a trialkoxysilane, with at least one compound of any one of Embodiments 16-34 and a base, optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

[0508] Embodiment 42 provides a method of promoting borylation of an alkene, the method comprising contacting the alkene and a borylating agent with at least one compound of any one of Embodiments 16-34 and a base, optionally wherein the borylating agent is bis(pinacolato)diboron (Etepim), optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

[0509] Embodiment 43 provides a method of promoting borylation of an alkyne, the method comprising contacting the alky ne and a bory lating agent with at least one compound of any one of Embodiments 16-34 and a base, optionally wherein the borylating agent is bis(pinacolato)diboron (Ehpim). optionally wherein the base is an alkoxide base, and optionally wherein M is Cu or Ag.

[0510] Embodiment 44 provides a method of promoting a reduction of an alkyne, the method comprising contacting the alky ne and a reducing agent with at least one compound of any one of Embodiments 16-34 and a base, optionally wherein the base is an alkoxide base, optionally wherein the contacting further occurs in the presence of an alcohol, optionally wherein the reducing agent is a silane, optionally wherein the silane is polymethylhydrosiloxane (PHMS), and optionally wherein M is Cu.

[0511] Embodiment 45 provides a method of promoting oxidation of an aldehyde, the method comprising contacting the aldehyde and a base in the presence of O2 (g) with at least one compound of any one of Embodiments 16-34, optionally wherein the contacting occurs in the presence of an alcohol, optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

[0512] Embodiment 46 provides a method of promoting oxidation of an alcohol, the method comprising contacting the alcohol and a base in the presence of O2 (g) with at least one compound of any one of Embodiments 16-34, optionally wherein the base is a hydroxide base, and optionally wherein M is Cu.

[0513] Embodiment 47 provides a method of promoting a reaction between an aryl halide or heteroaryl halide and an amine, the method comprising contacting the aryl halide or heteroaryl halide and the amine with at least one compound of any one of Embodiments 16- 34 and a base, optionally wherein the halide is a chloride, optionally wherein the base is an alkoxide base, optionally wherein M is Pd.

[0514] Embodiment 48 provides a method of promoting an oxidation of an alkene, the method comprising contacting the alkene and an oxidizing agent with at least one compound of any one of Embodiments 16-34, optionally wherein the oxidizing agent is a peroxide, and optionally wherein M is Pd.

[0515] Embodiment 49 provides a method of promoting hydrogenation of an arene or heteroarene, the method comprising contacting the arene or heteroarene and H2 (g) with at least one compound of any one of Embodiments 16-34, optionally wherein M is Ir or Rh. Embodiment 50 provides the method of any one of Embodiments 35-49, wherein at least one of the following applies:

[0516] (a) the terminal alkyne and carboxylic acid are covalently linked by a C2-C6 alkylenyl which is optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C6 alkyl. C1-C6 alkoxy, C?-Cs cycloalkyl, C3-C8 cycloalkoxy, CN, and NO2, wherein the C1-C6 alkyl, C1-C6 alkoxy, C3-C8 cycloalkyl, and C3-C8 cycloalkoxy are each independently optionally substituted with at least one selected from the group consisting of halogen, CN, NO2, C1-C3 alkoxy, C1-C3 haloalky 1, and C1-C3 haloalkoxy;

[0517] (b) the alkyne is a C2-C6 alkyne, wherein the C2-C6 alkyne is optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alky l, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl, wherein each C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl is optionally substituted with at least one selected from the group consisting of NH2, NH(C1-C6 alkyl), N(C1-C6 alky 1)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1- Ce alkyl), and C(=O)N(C1-C6 alkyl)2;

[0518] (c) the aniline is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroaryl is substituted with at least one NH2 moiety, and further optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2;

[0519] (d) the propargy l amide is a C6-C10 ary l or C2-C8 heteroaryl, wherein the C6-C10 ary l or C2-C8 heteroaryl is substituted with at least one -C(=O)NHCH2C=CH moiety, and further optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1-C6 alkyl)2, halogen, OH. CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl). C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2;

[0520] (e) the arene or heteroarene is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroaryl is optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2;

[0521] (f) the alkene is a C2-C6 alkene, wherein the C2-C6 alkene is optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alky l, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl, wherein each C1-C6 alkoxy. C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl is optionally substituted with at least one selected from the group consisting of NH2, NH(C1-C6 alkyl), N(C1-C6 alky 1)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alky l), C(=O)NH2, C(=O)NH(C1- Cs alkyl), and C(=O)N(C1-C6 alkyl)2;

[0522] (g) the ketone is R’C(=O)R’’, wherein R’ and R” are each independently selected from the group consisting of C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl, wherein the C1-C6 alky l, C3-C8 cycloalkyd, C2-C8 heterocycloalkyl. C6-C10 aryl, and C2-C8 heteroaryl are each independently optionally- substituted with at least one selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyd, C2-C6 alkenyl, pheny l, naphthyl, pyridyl, NH2, NH(C1-C6 alkyd), N(C1-C6 alky 1)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1- C>, alkyl), and C(=O)N(C1-C6 alkyl)2;

[0523] (h) the aldehyde is R’C(=O)H, wherein R’ is selected from the group consisting of C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroary 1, wherein the C1-C6 alkyd, C3-C8 cycloalkyd, C2-C8 heterocy cloalkyd, C6-C10 ary 1, and C2-C8 heteroaiyl are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy. C1-C6 haloalkoxy, C1-C6. haloalkyl, C1-C6 alkyd, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyd), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2;

[0524] (i) the alcohol is R’CH20H, wherein R’ is selected from the group consisting of C1-C6 alkyd, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl, wherein the C1-C6 alkyl, C3-C8 cycloalkyl. C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2. C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2; and

[0525] (j) the aryl halide or heteroaryl halide is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroaryl is substituted with at least one halogen selected from the group consisting of Cl, Br, and I. and further optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1-C6 alky 1)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyd), and C(=O)N(C1-C6 alkyl)2.

[0526] The terms and expressions employed herein are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the embodiments of the present application. Thus, it should be understood that although the present application describes specific embodiments and optional features, modification and variation of the compositions, methods, and concepts herein disclosed may be resorted to by those of ordinary’ skill in the art, and that such modifications and variations are considered to be within the scope of embodiments of the present application.

Claims

CLAIMSWhat is claimed is:

1. A compound of formula (I):wherein:R1and R2are each independently selected from the group consisting of optionally substituted C6-C10 aryl, optionally substituted C2-C8 heteroaryl, optionally substituted C3-C8 cycloalkyl, or C2-C8 heterocycloalkyl. wherein at least one C6-C10 aryl or C2-C8 heteroaryl of R1or R2, if present, is substituted at one or two ortho positions thereof with -CH(optionally substituted C6-C10 aryl)2, and wherein at least one C3-C8 cycloalkyl or C2-C8 heterocycloalkyl of R1or R2, if present, comprises a quaternary carbon atom;R3is selected from the group consisting of optionally substituted C1-C6 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C2-C8 heterocycloalkyl, optionally substituted C6-C10 aryl, and optionally substituted C2-C8 heteroaryl;X1is a monovalent counter anion; each occurrence of optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, and optionally substituted heteroaryl, is independently optionally substituted with at least one selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy. C1-C3 haloalkoxy, CN. NO2. ORA. N(RA)(RB), C(=O)RA, C(=O)N(RA)(RB), C(=O)ORB, N(RA)S(=O)2RB, S(=O)2N(RA), C1-C6 alkyd, C3-C8 cycloalkyd, C2-Cs heterocycloalkyl, C6-C10 aryl, C2-Cs heteroary 1, C2-C6 alkenyl, and benzyl, wherein the C1-C6 alkyl, C3-C8 cycloalky 1. C2-C8 heterocycloalkyl, C6-C10 aryl, C2-Cs heteroaryl, C2-C6 alkenyl, and benzyl are each optionally substituted w ith at least one substituent selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyd, C2-C6 alkenyl, benzyl, phenyl, naphthyl, and pyridyl; andRAand RBare each independently selected from the group consisting of H. C1-C6 alkyl, C1-C3 haloalky 1, C2-C6 alkenyl, benzyd, naphthyl, C4-C10 heteroaryl, and phenyl, wherein each substituent in RAand RBis optionally substituted with at least one substituentselected from the group consisting of CN, NO2, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, and halogen.

2. The compound of claim 1, wherein R1is:wherein:Rla. Rlb, Rlc, Rld, and Rleare each independently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of Rla, Rlb, Rlc, Rld, and Rleis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzy l, phenyl, and naphthyl, and C2-C12 heterocyclyl.

3. The compound of claim 2, wherein Rla, Rlb, Rlc, Rld, and Rleare each independently7selected from the group consisting of H, methyl, isopropyl, and diphenylmethyl.

4. The compound of claim 2 or 3, wherein at least one of the following applies:(a) Rlband Rldare independently H;(b) Rlb, Rlc, and Rldare each independently H;(c) Rlaand Rleare identical; and(d) Rla. Rlc, and Rleare identical.

5. The compound of any one of claims 2-4, wherein one of the following applies:(a) Rlaand Rleare each independently optionally substituted C1-C6 alkyd, and Rlb, Rlc, and Rldare H; and(b) Rla. Rlc, andRlcare each independently optionally substituted C1-C6 alkyl, and Rlband Rldare H.

6. The compound of any one of claims 1-5. w herein R1is selected from the group consisting of:

7. The compound of any one of claims 1-6, wherein R2is:wherein:inc[ependently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of R2a. R2b, R2c, R2d. and R2eis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzy l, phenyl, and naphthyl, and C2-C12 heterocyclyl.

8. The compound of claim 7, wherein R2a, R2b, R2c, R2d, and R2eare each independently selected from the group consisting of H, methyl, isopropyl, and diphenylmethyl.

9. The compound of claim 7 or 8, wherein:(a) R2a. R2b, R2C, R2d. and R2eare each independently H;(b) R2band R2dare independently H;(b) R2b, R2C, and R2dare each independently H;(c) R2aand R2eare identical; and(d) R2a. R2C, and R2care identical.

10. The compound of any one of claims 7-9, wherein one of the following applies:(a) R2aand R2eare each independently optionally substituted C1-C6 alky l, and R2b, R2C. and R2dare H; and(b) R2a, R2e, andR2eare each independently optionally substituted C1-C6 alkyl, and R2band R2dare H.

11. The compound of any one of claims 1-10, wherein R2is selected from the group consisting of12. The compound of any one of claims 1-11, wherein one of the following applies:

13. The compound of any one of claims 1-12, wherein R3is selected from the group consisting of methyl, isopropyl, phenyl, and 2,6-diisopropylphenyl.

14. The compound of any one of claims 1-13, wherein X1is selected from the group consisting of halogen, OS(=O)2RA, OC(=O)RA, N(C(=0)RA)2, tetracoordinate boronate, and hexacoordinate phosphorus, optionally wherein X1is selected from the group consisting of I, BF4, and PF6.

15. The compound of any one of claims 1-14, which is selected from the group consisting of:

16. A compound of formula (II):wherein:M is a transition metal;R1and R2are each independently selected from the group consisting of optionally substituted C6-C10 aryl, optionally substituted C2-C8 heteroaryl, optionally substituted C3-C8 cycloalkyl, or C2-C8 heterocycloalkyl, wherein at least one C6-C10 aryl or C2-C8 heteroaryl of R1or R2, if present, is substituted at one or two ortho positions thereof with -CH(optionally substituted C6-C10 aryl)2, and wherein at least one C3-C8 cycloalkyl or C2-C8 heterocycloalkyd of R1or R2, if present, comprises a quaternary carbon atom;R3is selected from the group consisting of optionally substituted C1-C6 alkyl, optionally substituted C3-C8 cycloalkyl, optionally substituted C2-C8 heterocycloalkyl, optionally substituted C6-C10 aryl, and optionally substituted C2-C8 heteroary l;L is a ligand of M, wherein each occurrence of L can be the same or different;X2is a monovalent or divalent counter anion, wherein L and X2can be present in a single compound; each occurrence of optionally substituted alkyl, optionally substituted cycloalkyl, optionally substituted heterocycloalkyl, optionally substituted aryl, and optionally substituted heteroaryl, is independently optionally substituted with at least one selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy. C1-C3 haloalkoxy, CN. NO2. ORA. N(RA)(RB), C(=O)RA, C(=O)N(RA)(RB), C(=O)ORB, N(RA)S(=O)2RB, S(=O)2N(RA), C1-C6 alkyd, C3-C8 cycloalkyd, C2-C8 heterocycloalkyl, C6-C10 ary l, C2-C8 heteroaryd, C2-C6 alkenyl, and benzy l, wherein the C1-C6 alkyl, C3-C8 cycloalkyl. C2-C8 heterocycloalkyl, C6-C10 aryl, C2-C8 heteroaryl, C2-C6 alkenyl, and benzyl are each optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C3 haloalkyl, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyd, C2-C6 alkenyl, benzyl, phenyl, naphthyl, and pyridyl;RAand RBare each independently selected from the group consisting of H. C1-C6 alkyl, C1-C3 haloalky 1, C2-C6 alkenyl, benzyd, naphthyl, C4-C10 heteroaryl, and phenyl,wherein each substituent in RAand RBis optionally substituted with at least one substituent selected from the group consisting of CN, NO2, C1-C3 haloalkyl, C1-C3 alkoxy. C1-C3 haloalkoxy, C1-C3 alkyl, and halogen; m is an integer which is selected from the group consisting of 0, 1, 2, and 3; and n is an integer which is selected from the group consisting of 0, 1, and 2.

17. The compound of claim 16, wherein R1is:wherein:Rla, Rlb, Rlc, Rld, and Rleare each independently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of Rla, Rlb, Rlc, Rld, and Rleis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

18. The compound of claim 17, wherein Rla, Rlb, Rlc. Rld, and Rleare each independently selected from the group consisting of H, methyl, isopropyl, and diphenylmethyl.

19. The compound of claim 17 or 18, wherein at least one of the following applies:(a) Rlband Rldare independently H;(b) Rlb, Rle, and Rldare each independently H;(c) Rlaand Rleare identical; and(d) Rla, Rlc, and Rleare identical.

20. The compound of any one of claims 17-19, wherein one of the following applies:(a) Rlaand Rleare each independently optionally substituted C1-C6 alkyl, and Rlb, Rlc, and Rldare H; and(b) Rla, Rlc, andRleare each independently optionally substituted C1-C6 alkyl, and Rlband Rldare H.

21. The compound of any one of claims 16-20, wherein R1is selected from the group consisting of:

22. The compound of any one of claims 16-21, wherein R2is:wherein:R2a. R2b, R2C. R2d, and R2eare each independently selected from the group consisting of H, halogen, optionally substituted C1-C6 alkyl and optionally substituted C1-C6 alkoxy, wherein each optional substituent in each of R2a, R2b, R2c, R2d, and R2eis independently selected from the group consisting of halogen, C1-C3 haloalkyl, C1- C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C2-C6 alkenyl, benzyl, phenyl, and naphthyl, and C2-C12 heterocyclyl.

23. The compound of claim 22, wherein R2a, R2b, R2c, R2d, and R2eare each independently selected from the group consisting of H. methyl, isopropyl, and diphenylmethyl.

24. The compound of claim 22 or 23, wherein:(a) R2a, R2b, R2C, R2d, and R2eare each independently H;(b) R2band R2dare independently H;(b) R2b. R2C, and R2dare each independently H;(c) R2aand R2eare identical; and(d) R2a, R2C, and R2eare identical.

25. The compound of any one of claims 22-24, wherein one of the following applies:(a) R2aand R2Bare each independently optionally substituted C1-C6 alkyl, and R2b, R2C, and R2dare H; and(b) R2a, R2®, andR2® are each independently optionally substituted C1-C6 alkyl, and R2band R2dare H.

26. The compound of any one of claims 16-25, wherein R2is selected from the group consisting of:

27. The compound of any one of claims 16-26, wherein one of the following applies:

28. The compound of any one of claims 16-27, wherein R3is selected from the groupconsisting of methyl, isopropyl, phenyl, and 2,6-diisopropylphenyl.

29. The compound of any one of claims 16-28, wherein M is selected from the group consisting of Pd, Cu, Ag, Au, Ni, Pt, Co, Rh, Ir, Fe, Ru, and Os.

30. The compound of any one of claims 16-29, wherein M is selected from the group consisting of Au. Ag, Cu, Pd, Ir. and Rh.

31. The compound of any one of claims 16-30, wherein each L is independently selected from the group consisting of carbon monoxide (CO), optionally substituted C2-C12 alkene, and optionally substituted C5-C12 cycloalkene, optionally substituted benzylamine, optionally substituted C2-C8 heteroaryl, wherein each optional substituent in the C2-C12 alkene, C5-C12 cycloalkene, benzy lamine, and C2-C8 heteroaryl is independently selected from the group consisting of a halogen, CN, NO2, C1-C3 haloalky 1, C1-C3 alkoxy, C1-C3 haloalkoxy, C1-C3 alkyl, C3-C8 cycloalkyl, phenyl, and C2-C8 heterocyclyl.

32. The compound of any one of claims 16-31, wherein each L is independently selected from the group consisting of carbon monoxide (CO), cyclooctadiene (COD), and(1-phenylpropenide and l-phenylprop-2-en-l-ide; double bond thereof).

33. The compound of any one of claims 16-32, wherein each X2is independently selected from the group consisting of halogen, OS(=O)2RA, OC(=O)RA, N(C(=O)RA)2, optionally substituted allyl anion, tetracoordinate boronate, and hexacoordinate phosphorus, optionally wherein each X2is independently selected from the group consisting of Cl, I, and(1-phenylpropenide and l-phenylprop-2-en-l-ide; anion thereof).

34. The compound of any one of claims 16-33, which is selected from the group consisting of:(cod)Cl]).

35. A method of promoting an intramolecular cyclization of a compound compnsing a terminal alky ne and a carboxylic acid, the method comprising contacting the compound comprising the terminal alkyne and the carboxylic acid with at least one compound of any one of claims 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is sodium tetrakis[3,5- bis(trifluoromethyl)phenyl]borate (NaBArLj), and optionally wherein M is Au or Cu.

36. A method of promoting a reaction between an alkyne and an aniline, the method comprising contacting the alkyne and the aniline with at least one compound of any one of claims 16-34, optionally w herein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

37. A method of promoting an intramolecular cyclization of a compound comprising a propargyl amide, the method comprising contacting the propargyl amide with at least one compound of any one of claims 16-34, optionally w herein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is AgOTf, and optionally wherein M is Au.

38. A method of promoting a reaction between an alkyne and an arene, the method comprising contacting the alky ne and the arene w ith at least one compound of any one of claims 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

39. A method of promoting a reaction between an alkyne and an alkene, the method comprising contacting the alkyne and the alkene with at least one compound of any one of claims 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Au.

40. A method of promoting hydration of an alkyne, the method comprising contacting the alkyne and an aniline with at least one compound of any one of claims 16-34, optionally wherein the contacting occurs in the presence of a Lewis acid, optionally wherein the Lewis acid is NaBArF4, and optionally wherein M is Cu.

41. A method of promoting hydrosilylation of a ketone, the method comprising contacting the ketone and a tri alkoxy silane, with at least one compound of any one of claims 16-34 and a base, optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

42. A method of promoting borylation of an alkene, the method comprising contacting the alkene and a borylating agent with at least one compound of any one of claims 16-34 and a base, optionally wherein the borylating agent is bis(pinacolato)diboron (Ehpim), optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

43. A method of promoting borylation of an alkyne, the method comprising contacting the alkyne and a borylating agent with at least one compound of any one of claims 16-34 and a base, optionally wherein the borylating agent is bis(pinacolato)diboron (Ehpim), optionally wherein the base is an alkoxide base, and optionally wherein M is Cu or Ag.

44. A method of promoting a reduction of an alkyne, the method comprising contacting the alkyne and a reducing agent with at least one compound of any one of claims 16-34 and a base, optionally wherein the base is an alkoxide base, optionally wherein the contacting further occurs in the presence of an alcohol, optionally wherein the reducing agent is a silane, optionally wherein the silane is polymethylhydrosiloxane (PHMS), and optionally wherein M is Cu.

45. A method of promoting oxidation of an aldehyde, the method comprising contacting the aldehyde and a base in the presence of O2 (g) with at least one compound of any one of claims 16-34, optionally wherein the contacting occurs in the presence of an alcohol, optionally wherein the base is an alkoxide base, and optionally wherein M is Cu.

46. A method of promoting oxidation of an alcohol, the method comprising contacting the alcohol and a base in the presence of O2 (g) with at least one compound of any one of claims 16-34, optionally wherein the base is a hydroxide base, and optionally wherein M is Cu.

47. A method of promoting a reaction between an aryl halide or heteroaryl halide and an amine, the method comprising contacting the aryl halide or heteroaryl halide and the amine with at least one compound of any one of claims 16-34 and a base, optionally wherein the halide is a chloride, optionally wherein the base is an alkoxide base, optionally wherein M is Pd.

48. A method of promoting an oxidation of an alkene, the method comprising contacting the alkene and an oxidizing agent with at least one compound of any one of claims 16-34, optionally wherein the oxidizing agent is a peroxide, and optionally wherein M is Pd.

49. A method of promoting hydrogenation of an arene or heteroarene, the method comprising contacting the arene or heteroarene and H2 (g) with at least one compound of any one of claims 16-34, optionally wherein M is Ir or Rh.

50. The method of any one of claims 35-49. wherein at least one of the following applies:(a) the terminal alkyne and carboxylic acid are covalently linked by a C2-C6 alkylenyl which is optionally substituted with at least one substituent selected from the group consisting of halogen, C1-C6 alkyl. C1-C6 alkoxy, C3-C8 cycloalkyl, C3-C8 cycloalkoxy, CN, and NO2, wherein the C1-C6 alkyl, C1-C6 alkoxy, C3-C8 cycloalkyl, and C3-C8 cycloalkoxy are each independently optionally substituted with at least one selected from the group consisting of halogen, CN, NO2, C1-C3 alkoxy, C1-C3 haloalkyl, and C1-C3 haloalkoxy;(b) the alkyne is a C2-C6 alkyne, wherein the C2-C6 alkyne is optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl, wherein each C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl is optionally substituted with at least one selected from the group consisting of NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1- C6alkyl), and C(=O)N(C1-C6 alkyl)2;(c) the aniline is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroaryl is substituted with at least one NH2 moiety, and further optionallysubstituted with at least one substituent selected from the group consisting of C1-C6 alkoxy. C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2;(d) the propargyl amide is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroaryl is substituted with at least one -C(=O)NHCH2C=CH moiety, and further optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1-C6 alky 1)2. halogen, OH. CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl). C(=O)NH2, C(=O)NH(CI-C6 alkyl), and C(=O)N(C1-C6 alkyl)2;(e) the arene or heteroarene is a C6-C10 aryl or C2-C8 heteroaryl, wherein the C6-C10 aryl or C2-C8 heteroaryl is optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(~O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyl), and C(=O)N(C1-C6 alkyl)2;(f) the alkene is a C2-C6 alkene, wherein the C2-C6 alkene is optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alky l, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl, wherein each C1-C6 alkoxy. C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, and pyridyl is optionally substituted with at least one selected from the group consisting of NH2, NH(C1-C6 alkyl), N(C1-C6 alky 1)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alky l), C(=O)NH2, C(=O)NH(C1- C6alkyl), and C(=O)N(C1-C6 alkyl)2;(g) the ketone is R?C(=O)R’\ wherein R’ and R” are each independently selected from the group consisting of C1-C6 alkyl, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl, wherein the C1-C6 alky l, C3-C8 cycloalkyd, C2-C8 heterocycloalkyl. C6-C10 aryl, and C2-C8 heteroaryl are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyl, C1-C6 alky 1, C3-C8 cycloalkyl, C2-C8 heterocycloalkyd,C2-Ce alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyd), N(C1-C6 alkyl)2, halogen, OH. CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl). C(=O)NH2, C(=O)NH(C1- Ce alkyl), and C(=O)N(C1-C6 alkyl)2;(h) the aldehyde is R’C(=O)H, wherein R’ is selected from the group consisting of C1-C6 alky 1, C3-C8 cycloalky l, C2-C8 heterocycloalkyl, C6-C10 ary l, and C2-C8 heteroaryl, wherein the C1-C6 alkyl, C3-C8 cycloalkyd. C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyd, C1-C6 alkyd, C3-C8 cycloalkyd, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(CI-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyd), and C(=O)N(C1-C6 alkyl)2;(i) the alcohol is R’CH20H, wherein R’ is selected from the group consisting of C1-C6 alkyd, C3-C8 cycloalkyl, C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryd, wherein the C1-C6 alkyl, C3-C8 cycloalkyd. C2-C8 heterocycloalkyl, C6-C10 aryl, and C2-C8 heteroaryl are each independently optionally substituted with at least one selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyd, C1-C6 alkyd, C3-C8 cycloalkyd, C2-C8 heterocycloalkyl, C2-C6 alkenyl, phenyl, naphthyl, pyridyl, NH2, NH(C1-C6 alkyl), N(C1-C6 alkyl)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyd), C(=O)NH2, C(=O)NH(C1-C6 alkyd), and C(=O)N(CI-C6 alkyl)2; and(j) the aryl halide or heteroaryd halide is a C6-C10 aryl or C2-Cs heteroaryd, wherein the C6-C10 ary l or C2-Cs heteroaryl is substituted with at least one halogen selected from the group consisting of Cl, Br, and I. and further optionally substituted with at least one substituent selected from the group consisting of C1-C6 alkoxy, C1-C6 haloalkoxy, C1-C6, haloalkyd, C1-C6 alkyl, C3-C12 cycloalkyl, C2-C10 heterocyclyl, C2-C6 alkenyl, phenyl, naphthyl, NH2, N(C1-C6 alkyd)2, halogen, OH, CN, NO2, C(=O)OH, C(=O)O(C1-C6 alkyl), C(=O)NH2, C(=O)NH(C1-C6 alkyd), and C(=O)N(C1-C6 alkyl)2.

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