Organoboron compounds prepared based on the boronalkene / alkyne metathesis process and their use

Abstract

The application relates to the technical field of organic boron compounds, in particular to an organic boron compound prepared based on a boron olefin / alkyne metathesis method and application thereof. The organic boron compound is prepared based on a boron olefin / alkyne metathesis method, and the structural formula of the organic boron compound is shown as formula IV. The application takes 1,1,1-tri-boron alkane as raw material, generates boron olefin in-situ as a non-metal alkylating agent, and reacts with alkyne to generate metathesis reaction, and then reacts with an electrophilic reagent to obtain diversified functionalized borate derivatives. The application overcomes the limitation of traditional metathesis reaction which depends on transition metal catalysts, has the advantages of mild reaction condition, high atom economy, wide substrate application range and the like, and the obtained products include secondary / tertiary borate, geminal diboron silane and 1,3-diene, and have wide application prospects in the fields of drug synthesis and material science.

Description

Technical Field

[0002] This invention relates to the field of organoboron compound technology, specifically to an organoboron compound prepared by a boroolefin / alkyne metathesis method and its applications. Background Technology

[0004] Metathesis reactions have evolved into a highly efficient and atom-economical strategy for constructing carbon-carbon unsaturated bonds. As a cornerstone transformation in modern organic synthesis and complex molecular assembly, they encompass various variants, including alkenes, alkynes, and ene-yyn metathesis, and have been widely applied in drug development, materials science, and chemical biology. Traditionally, metathesis reactions have primarily involved carbon-carbon double or triple bonds, while research on reactions involving heteroatom alkenes has been relatively scarce, with only recent progress in carbonyl-involved metathesis reactions. This imbalance may stem from the dependence of most mature metathesis reactions on metal carbene catalysts and metal heterocyclic intermediates. These catalysts are highly efficient for carbon-carbon unsaturated bonds, but due to differences in double bond polarity, metal heterocyclic stability, and metal-heteroatom interactions, they are often incompatible with heteroatom alkenes. Therefore, the development of heteroatom alkene metathesis reactions points to the attractive alternative of a "transition metal-free strategy," but this field remains highly challenging due to the extreme difficulty in obtaining sufficiently active and controllable carbene equivalents (especially for heteroatom alkene transformations) in the absence of transition metal centers.

[0005] Despite the challenging nature of this transformation, the widespread presence of heteroatoms in pharmaceuticals, functional materials, and other complex molecules has inspired the expansion of metathesis chemistry into non-transition metal catalysis and non-carbon-carbon multiple bond domains, with some sporadic reports already available. For instance, the thermally induced cross-metathesis of diborenes via π-acceptor cyclic alkyl (amino)carbene (CAAC) ligands has provided preliminary evidence that boron compounds can promote the metathesis of metal-free heteroatom alkenes. In addition to neutral diborenes, "boron-heterenes," as α-boron-based carbanion resonance forms, have also been shown to serve as non-metallic carbene substitutes in the boron-Wittig reaction. Similarly, Morken and collaborators demonstrated that boron-heterenes can form stable boron heterocycles via [2+2] cycloaddition with nonpolar π bonds, after which these intermediates are captured by electrophiles rather than converted into metathesis products. Based on these precedents and the following considerations, it is conceivable that transition metal-free boron-based olefin / alkyne metathesis is achievable: (i) adjacent sp2 hybrid boron atoms can stabilize the carbanion center by donating electrons to their empty p orbitals, giving the C–B bond a significant π-bond characteristic, similar to a carbene; (ii) boron-based olefins exhibit higher reactivity than C=C and C=O bonds, requiring no additional activators; (iii) boron and carbon are both 2p elements, conferring stability to the four-membered boron heterocycles formed during metathesis; and (iv) their resonance stability characteristics make subsequent functionalization more flexible than that of metal-based carbenes.

[0006] Imagine a transition metal-free boroene-yyn metathesis reaction between boroenes and alkynes, providing an efficient and universal method for synthesizing functionalized boroene esters and their derivatives. This reaction can be seamlessly integrated into a one-pot, multi-component cross-coupling process, achieving sequential functionalization starting from 1,1,1-triborylalkanes by combining deboronization, metathesis, and electrophilic trapping. The regioselectivity of the ring-closing metathesis is determined by the distance between the α-boron carbanion and the carbon-carbon triple bond. A variety of electrophiles, including haloalkanes, chlorosilanes, water, and carbonyl groups, can participate efficiently in this process, yielding various secondary and tertiary boroene esters, geminitrosilylalkanes, and 1,3-dienes. Notably, the metathesis reaction can be sequentially trapped by esters and additional electrophiles, generating highly functionalized ketones or enol ethers via a one-pot, four-step sequence, further demonstrating its synthetic practicality. This metal-free metathesis strategy redefines the role of "boron carbene," transforming it into a multifunctional, resonantally stable carbon-carbon recombination mediator and laying a new conceptual foundation for advancing multiboron chemistry. Summary of the Invention

[0008] The purpose of this invention is to provide an organoboron compound prepared by a boroolefin / alkyne metathesis method and its application. This invention solves the problems of dependence on metal catalysts and narrow substrate range in the prior art through a highly efficient and multifunctional transition metal-free boroolefin / alkyne metathesis reaction.

[0009] To achieve the above objectives, this application provides the following technical solution:

[0010] An organoboron compound prepared by a boroolefin / alkyne metathesis method, the structural formula of which is shown in Formula IV:

[0011]

[0012] In Equation IV, R 1 Selected from unsubstituted alkyl, substituted alkyl, unsubstituted aryl, or substituted aryl, R 2 The compound is selected from unsubstituted alkyl, substituted alkyl, unsubstituted aryl, substituted aryl, unsubstituted heteroaryl, substituted heteroaryl, or trimethylsilyl, and E is selected from unsubstituted alkyl, substituted alkyl, unsubstituted aryl, substituted aryl, or carbonyl compounds.

[0013] Preferably, R 1 Selected from C1-C 20 Straight chain, C1-C 20 Branched alkyl groups, C3-C 20 The cycloalkyl, unsubstituted aryl, or substituted aryl group, wherein the substituent on the aryl group is selected from one or more of halogens, C1-C6 alkyl groups, C1-C6 alkoxy groups, and trifluoromethyl groups; R 2 Selected from unsubstituted aryl, substituted aryl, unsubstituted heteroaryl, substituted heteroaryl, C1-C 12 The alkyl or trimethylsilyl group, wherein the substituents on the aryl group are selected from C1-C6 alkyl, C1-C6 alkoxy, halogen, cyano, ester or aryl groups.

[0014] A method for preparing an organoboron compound as described above includes the following steps:

[0015] The 1,1,1-triborylalkane shown in Formula I and the alkyne shown in Formula II were mixed with a base and subjected to a boroalkene / alkyne metathesis reaction. Then, the electrophilic reagent shown in Formula III was added for capture to obtain organoboron compound IV.

[0016]

[0017] Among them, R 1 Selected from alkyl, alkyl derivatives, aryl or aryl derivatives, R 2The reagent is selected from alkyl, alkyl derivatives, aryl or aryl derivatives, and E is selected from alkyl, alkyl derivatives, aryl, aryl derivatives or carbonyl compounds; the electrophilic reagent is selected from haloalkanes, chlorosilanes, water, aldehydes or esters.

[0018] Preferably, under the protection of an inert gas, the 1,1,1-triborylalkane shown in Formula I and the alkyne shown in Formula II are mixed with a base in an organic solvent to carry out a boroolefin / alkyne metathesis reaction, wherein the organic solvent is an ether solvent, an aromatic hydrocarbon solvent or a polar aprotic solvent.

[0019] More preferably, the organic solvent is tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane (DME), or toluene.

[0020] Preferably, the molar ratio of the 1,1,1-triborylalkane, alkyne compound and base is 1-2:1:2-5, wherein the preferred molar ratio is 1.2-2.0:1:2.5-4.0, and the optimal molar ratio is 1.5:1:3.

[0021] More preferably, the alkali is selected from potassium tert-butoxide (KOtBu), sodium tert-butoxide (NaOtBu), lithium tert-butoxide (LiOtBu), sodium hydride (NaH), or bis(trimethylsilyl)aminopotassium.

[0022] More preferably, the reaction temperature of the metathesis reaction is 60–120 °C, and the reaction time is 0.5–12 h. The reaction temperature of the metathesis stage is preferably 80–110 °C, and most preferably 100 °C.

[0023] More preferably, the molar ratio of the alkyne compound represented by Formula II to the electrophilic reagent is 1:1 to 3, and the optimal molar ratio of the alkyne compound represented by Formula II to the electrophilic reagent is 1:2; the reaction temperature of the electrophilic reagent capture stage is -20 ℃ to 30 ℃, the preferred reaction temperature of the electrophilic reagent capture stage is room temperature (20 to 25 ℃), and the capture time is 0.1 to 2 h.

[0024] The application of an organoboron compound prepared by the boroolefin / alkyne metathesis method as described above as an intermediate in functional materials.

[0025] Beneficial effects:

[0026] (1) High atom economy: This invention achieves rapid construction of organoboron molecular structures through one-pot multi-component coupling (deborylation-metathesis-electrophilic capture).

[0027] (2) Product diversity: By changing the electrophilic reagent, the present invention can obtain a variety of products such as borate esters, geminosine, 1,3-diene and highly substituted ketones.

[0028] (3) It does not rely on metal catalysts. This invention does not require the use of expensive or toxic transition metal catalysts, thus reducing environmental pollution and purification costs. Attached Figure Description

[0030] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein:

[0031] Figure 1 The 1H NMR spectrum of the tertiary borate ester compound (IV-1) prepared in Example 1;

[0032] Figure 2 The image shows the carbon NMR spectrum of the tertiary borate ester compound (IV-1) prepared in Example 1.

[0033] Figure 3 The NMR boron spectrum of the tertiary boron ester compound (IV-1) prepared in Example 1 is shown.

[0034] Figure 4 This is a diagram showing the synthesis and transformation of tertiary borate esters. Detailed Implementation

[0036] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will understand that modifications and variations can be made to the present application without departing from the scope or spirit of the present application. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0037] This invention provides a method for preparing an organoboron compound, comprising the following steps:

[0038] Under inert gas protection, 1,1,1-triborylalkanes of Formula I and alkynes of Formula II were mixed with a base in an organic solvent and reacted at 60–120 °C for 0.5–12 h. After the reaction system was cooled to room temperature, an electrophilic reagent of Formula III was added to carry out a capture reaction at room temperature. After reacting for 0.1–2 h, the functionalized organoboron compound was obtained by separation and purification. The reaction formula is as follows:

[0039]

[0040] In the 1,1,1-triboronylalkane shown in Formula I: R 1 Selected from C1-C 20 Straight chain, C1-C 20 Branched alkyl groups, C3-C 20 The aryl group is a cycloalkyl group, an unsubstituted aryl group, or a substituted aryl group, wherein the substituent on the aryl group is selected from one or more of halogens (F, Cl, Br, I), C1-C6 alkyl groups, C1-C6 alkoxy groups, and trifluoromethyl groups.

[0041] In the alkyne compounds shown in Formula II: R 2 Selected from unsubstituted aryl, substituted aryl, unsubstituted heteroaryl (such as pyridine, thiophene, furan), substituted heteroaryl (such as pyridine, thiophene, furan), C1-C 12 The alkyl or trimethylsilyl (TMS) group, wherein the substituent on the aryl group is selected from C1-C6 alkyl, C1-C6 alkoxy, halogen, cyano, ester or aryl groups.

[0042] In the electrophilic reagent shown in Formula III: the electrophilic reagent is selected from the following categories according to the structure of the target product: (1) used to synthesize tertiary / secondary borate esters, selected from allyl bromide, benzyl bromide, C1-C 12 (1) Iodinated alkanes or proton sources (such as water or alcohol); (2) Used to synthesize gem-diboranes, selected from trimethylchlorosilane (TMSCl), triethylchlorosilane (TESCl) or dimethylphenylchlorosilane; (3) Used to synthesize 1,3-dienes, selected from substituted or unsubstituted aromatic aldehydes (such as benzaldehyde, p-methoxybenzaldehyde) or aliphatic aldehydes.

[0043] The base is selected from strong bases, preferably potassium tert-butoxide (KOtBu), sodium tert-butoxide (NaOtBu), lithium tert-butoxide (LiOtBu), sodium hydride (NaH), or potassium bis(trimethylsilyl)amino (KHMDS); most preferably KOtBu.

[0044] The organic solvent is selected from ether solvents, aromatic hydrocarbon solvents or polar aprotic solvents; preferably tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane (DME) or toluene.

[0045] The molar ratio of compound I, compound II, base and electrophilic reagent III is 1.2–2.0:1:2.5–4.0:1.5–3.0; the optimal molar ratio is 1.5:1:3.0:2.0.

[0046] Reaction temperature: The temperature of the metathesis stage is preferably 80 to 110 ℃, and most preferably 100 ℃; the temperature of the electrophilic capture stage is preferably -20 ℃ to 30 ℃, and most preferably room temperature (20 to 25 ℃).

[0047] Reaction Mechanism: The transition metal-free boroolefin / alkyne metathesis reaction of the present invention is achieved through the following pathway: (1) In-situ generation of boroolefins: Under the action of a strong base, the 1,1,1-triborylalkane shown in Formula I undergoes deboronization / elimination, generating a highly reactive boroolefin intermediate in situ; (2) [2+2] cycloaddition and cycloisomerization: The boroolefin, as a non-metallic alkylating agent, undergoes [2+2] cycloaddition with the alkyne (Formula II) to form a borocyclobutene intermediate, which then undergoes cycloisomerization to achieve the recombination of boron atoms and carbon atoms, forming a novel boroolefin; (3) Electrophilic capture: The novel boroolefin intermediate, as a nucleophile, attacks the subsequently added electrophile (Formula III), thereby introducing a specific functional group at the α-position of the original alkyne while retaining the borate ester group.

[0048] Example 1: Synthesis of Tertiary Borate IV-1

[0049]

[0050] Under a nitrogen atmosphere, 0.45 mmol of 1,1,1-triborylalkane I-1, 0.30 mmol of alkyne II-1, and KO were added to the pressure-resistant tube. t Bu (0.90 mmol) and 3 mL THF were added. The mixture was stirred at 100 °C for 1 h. After cooling to room temperature, allyl bromide III-1 (0.60 mmol) was added, and the reaction was carried out for 2 min. The solvent was removed by rotary evaporation under reduced pressure, and the target product was purified by silica gel column chromatography with a separation yield of 81%.

[0051]

[0052] Figure 1-3 The images show the 1H NMR spectrum, 1C NMR spectrum, and 1B NMR spectrum of the tertiary borate ester compound (IV-1) prepared in Example 1.

[0053] The characterization data are: 1H NMR (400 MHz, CDCl3) δ 7.47 – 7.38 (m, 2H), 7.26 (t, J =7.6 Hz, 2H), 7.21 – 7.15 (m, 2H), 7.15 – 7.08 (m, 2H), 6.99 (d, J = 6.8 Hz, 2H), 5.81 – 5.67 (m, 1H), 5.04 – 4.86 (m, 2H), 3.15 (dd, J = 92.6, 15.5 Hz,2H), 2.84 (d, J = 7.1 Hz, 2H), 2.58 – 2.33 (m, 2H), 2.25 – 2.02 (m, 2H), 1.81– 1.63 (m, 2H), 1.14 (s, 12H).

[0054] 13 C NMR (100 MHz, CDCl3) δ 145.6, 140.6, 139.7, 137.3, 136.6, 129.2,129.1, 127.9, 127.8, 125.5, 125.2, 116.4, 83.5, 41.3, 36.9, 36.8, 36.7, 24.9,24.3, 22.2.

[0055] 11 B NMR (128 MHz, CDCl3) δ 32.79.

[0056] HRMS (ESI + m / z: [M+H] + Theoretical value: C 28 H 36 BO2 + 415.2802, Measured value: 415.2803.

[0057] IR (neat, cm -1 ): 2975, 2928, 1346, 1316, 1141, 850, 670.

[0058] Example 2: Synthesis of Tertiary Borate IV-2

[0059]

[0060] In this example, the allyl bromide used in Example 1 was replaced with an equimolar amount of (E)-(3-bromoprop-1-en-1-yl)benzene, and the other steps were the same as in Example 1, with a yield of 74%.

[0061] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.53 – 7.46 (m, 2H), 7.35 – 7.27(m, 6H), 7.24 – 7.11 (m, 5H), 7.05 – 6.98 (m, 2H), 6.42 (d, J = 15.8 Hz, 1H),6.23 – 6.11 (m, 1H), 3.36 – 3.04 (m, 2H), 3.03 – 2.96 (m, 2H), 2.65 – 2.40(m, 2H), 2.28 – 2.05 (m, 2H), 1.82 – 1.63 (m, 2H), 1.15 (d, J = 3.2 Hz, 12H).

[0062] 13 C NMR (100 MHz, CDCl3) δ 145.5, 140.5, 139.6, 138.3, 136.7, 131.7,129.4, 129.2, 129.0, 128.6, 127.91, 127.86, 126.8, 126.0, 125.5, 125.3, 83.5,40.2, 36.90, 36.88, 36.7, 24.9, 24.3, 22.3.

[0063] 11 B NMR (128 MHz, CDCl3) δ 32.47.

[0064] HRMS (ESI + m / z: [M+H] + Theoretical value: C 34 H 40 BO2 + 491.3116, Measured value: 491.3115.

[0065] IR (neat, cm -1 ): 2975, 2929, 1316, 1140, 964, 732, 697.

[0066] Example 3: Synthesis of Tertiary Borate IV-3

[0067]

[0068] In this embodiment, equimolar amounts of 6-bromo-1-hexene were used to replace the allyl bromide used in Example 1, and the other steps were the same as in Example 1, with a yield of 75%.

[0069] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.46 – 7.41 (m, 2H), 7.29 – 7.22(m, 2H), 7.21 – 7.16 (m, 2H), 7.15 – 7.09 (m, 2H), 6.99 – 6.92 (m, 2H), 5.89– 5.73 (m, 1H), 5.08 – 4.83 (m, 2H), 3.14 (dd, J = 104.1, 15.4 Hz, 2H), 2.65– 2.36 (m, 2H), 2.24 – 2.09 (m, 2H), 2.07 – 1.96 (m, 4H), 1.80 – 1.60 (m,2H), 1.41 (p, J = 7.2 Hz, 2H), 1.33 – 1.19 (m, 2H), 1.15 (s, 12H).

[0070] 13 C NMR (100 MHz, CDCl3) δ 146.3, 140.8, 140.4, 139.4, 136.2, 129.2,129.1, 127.9, 127.7, 125.5, 125.0, 114.2, 83.3, 37.0, 36.9, 36.8, 36.7, 33.9,29.7, 26.6, 24.8, 24.3, 22.2.

[0071] 11 B NMR (128 MHz, CDCl3) δ 33.95.

[0072] HRMS (ESI + m / z: [M+H] + Theoretical value: C 31 H 42 BO2 + 457.3272, Measured value: 457.3276.

[0073] IR (neat, cm -1 ): 2976, 2930, 1448, 1324, 1141, 699.

[0074] Example 4: Synthesis of Tertiary Boronate IV-4

[0075]

[0076] In this embodiment, equimolar amounts of 1-bromo-2-butyne were used to replace the allyl bromide used in Example 1, and the other steps were the same as in Example 1, with a yield of 71%.

[0077] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.51 – 7.43 (m, 2H), 7.31 – 7.26(m, 2H), 7.23 – 7.09 (m, 4H), 7.07 – 7.02 (m, 2H), 3.35 – 3.04 (m, 2H), 2.94– 2.74 (m, 2H), 2.59 – 2.44 (m, 2H), 2.28 – 2.06 (m, 2H), 1.81 – 1.66 (m,4H), 1.17 (s, 12H).

[0078] 13 C NMR (100 MHz, CDCl3) δ 144.7, 140.5, 139.4, 136.5, 129.2, 129.0,127.9, 127.7, 125.54, 125.45, 83.7, 78.5, 77.0, 36.9, 36.8, 36.7, 27.3, 24.8,24.3, 22.2, 3.7.

[0079] 11 B NMR (128 MHz, CDCl3) δ 34.57.

[0080] HRMS (ESI + m / z: [M+H] + Theoretical value: C 29 H 36 BO2 + 427.2802, Measured value: 427.2801.

[0081] IR (neat, cm -1 ): 2977, 2934, 1314, 1258, 1133, 850, 758, 693.

[0082] Example 5: Synthesis of Olefin IV-5

[0083]

[0084] In this embodiment, isovaleraldehyde was used to replace allyl bromide used in Example 1, and the other steps were the same as in Example 1, with a yield of 60%.

[0085] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.46 – 7.42 (m, 1H), 7.40 – 7.34(m, 2H), 7.33 – 7.25 (m, 3H), 7.25 – 7.19 (m, 2H), 7.18 – 7.12 (m, 2H), 6.10(t, J = 7.3 Hz, 0H), 5.74 (t, J = 7.4 Hz, 1H), 3.39 (d, J = 11.8 Hz, 2H), 2.52 – 2.38 (m, 3H), 2.33 (t, J = 7.5 Hz, 1H), 2.11 (t, J = 7.0 Hz, 1H), 2.03(t, J = 7.1 Hz, 1H), 1.92 (p, J = 7.5 Hz, 1H), 1.80 (pd, J = 7.4, 7.0, 3.6Hz, 2H), 1.68 (dq, J = 13.3, 6.7 Hz, 1H), 1.02 (d, J = 6.7 Hz, 3H), 0.91 (d,J = 6.7 Hz, 3H).

[0086] 13 C NMR (100 MHz, CDCl3) δ 140.9, 140.8, 140.5, 140.3, 139.2, 139.0,138.9, 137.9, 136.9, 135.4, 129.2, 129.1, 129.0, 128.6, 128.5, 128.3, 128.2,128.0, 126.8, 126.5, 126.3, 125.7, 125.6, 77.4, 77.1, 76.8, 39.1, 38.0, 37.2,37.0, 36.8, 36.1, 35.6, 35.2, 29.1, 28.8, 22.7, 22.53, 22.47, 21.8.

[0087] HRMS (ESI + m / z: [M+H] + Theoretical value: C 24 H 29+ 317.2263, Measured value: 317.2263.

[0088] IR (neat, cm -1 ): 2951, 2843, 1493, 1303, 1140, 1028, 760, 695, 674.

[0089] Example 6: Synthesis of Ketone IV-6

[0090]

[0091] In this embodiment, methyl butyrate was used instead of allyl bromide in Example 1, and the other steps were the same as in Example 1, with a yield of 65%.

[0092] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.37 – 7.24 (m, 5H), 7.24 – 7.18(m, 3H), 7.16 – 7.10 (m, 2H), 4.93 (s, 1H), 3.61 – 3.45 (m, 2H), 2.66 – 2.45(m, 1H), 2.43 – 2.39 (m, 2H), 2.33 – 2.19 (m, 3H), 1.87 – 1.66 (m, 2H), 1.65– 1.53 (m, 2H), 0.87 (t, J = 7.4 Hz, 3H).

[0093] 13 C NMR (100 MHz, CDCl3) δ 209.2, 139.6, 138.4, 138.0, 134.3, 129.0,128.64, 128.63, 128.57, 127.0, 126.2, 57.9, 44.2, 36.3, 35.1, 34.2, 21.8,17.5, 13.8.

[0094] HRMS (ESI + m / z: [M+H] + Theoretical value: C 23 H 26 O + 319.2056, Measured value: 319.2056.

[0095] IR (neat, cm -1): 2928, 1712, 1493, 1452, 725, 697.

[0096] Example 7: Tertiary borate ester IV-7

[0097]

[0098] In this embodiment, equimolar amounts of 2,2',2''-[2-(3-methylphenyl)ethane-1,1,1-triyl]tris(4,4,5,5-tetramethyl-1,3,2-dioxoborheptacyclopentane) were used instead of the 2,2',2''-(2-phenylethane-1,1,1-triyl)tris(4,4,5,5-tetramethyl-1,3,2-dioxoborheptacyclopentane) used in Example 1, and the other steps were the same as in Example 1, with a yield of 85%.

[0099] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.48 – 7.39 (m, 2H), 7.31 – 7.21(m, 2H), 7.17 – 7.03 (m, 2H), 6.94 (d, J = 7.5 Hz, 1H), 6.81 (d, J = 7.6 Hz, 1H), 6.73 (d, J = 1.9 Hz, 1H), 5.83 – 5.64 (m, 1H), 5.16 – 4.82 (m, 2H), 3.12 (dd, J = 95.8, 15.3 Hz, 2H), 2.84 (dd, J = 7.2, 1.6 Hz, 2H), 2.64 – 2.37 (m,2H), 2.28 (s, 3H), 2.24 – 2.06 (m, 2H), 1.79 – 1.62 (m, 2H), 1.15 (d, J = 2.3Hz, 12H).

[0100] 13 C NMR (100 MHz, CDCl3) δ 145.7, 140.5, 139.5, 137.34, 137.29, 136.7,130.0, 129.1, 127.8, 126.3, 126.2, 125.2, 116.3, 83.5, 41.4, 36.9, 36.8,36.7, 24.9, 24.3, 22.1, 21.5.

[0101] 11 B NMR (128 MHz, CDCl3) δ 32.11.

[0102] HRMS (ESI + m / z: [M+H] + Theoretical value: C 29 H 38 BO2 + 429.2959, Measured value: 429.2959.

[0103] IR (neat, cm -1 ): 2976, 2927, 1370, 1345, 1314, 1141, 849, 699.

[0104] Example 8: Tertiary borate ester IV-8

[0105]

[0106] In this embodiment, equimolar amounts of 2,2',2''-[2-(3,5-dimethylphenyl)ethane-1,1,1-triyl]tris(4,4,5,5-tetramethyl-1,3,2-dioxoborhecyclopentane) were used instead of the 2,2',2''-(2-phenylethane-1,1,1-triyl)tris(4,4,5,5-tetramethyl-1,3,2-dioxoborhecyclopentane) used in Example 1, and the other steps were the same as in Example 1, with a yield of 73%.

[0107] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.46 – 7.39 (m, 2H), 7.28 – 7.21(m, 2H), 7.17 – 7.09 (m, 1H), 6.75 (s, 1H), 6.54 (d, J = 1.7 Hz, 2H), 5.80 –5.66 (m, 1H), 5.05 – 4.88 (m, 2H), 3.07 (dd, J = 96.9, 15.2 Hz, 2H), 2.87 –2.77 (m, 2H), 2.61 – 2.34 (m, 2H), 2.23 (s, 6H), 2.20 – 2.04 (m, 2H), 1.77 –1.61 (m, 2H), 1.15 (d, J = 3.8 Hz, 12H).

[0108] 13C NMR (100 MHz, CDCl3) δ 145.9, 140.4, 139.4, 137.3, 137.2, 136.8,129.2, 127.8, 127.14, 127.08, 125.2, 116.3, 83.5, 41.5, 37.0, 36.8, 36.7,24.9, 24.3, 22.1, 21.4.

[0109] 11 B NMR (128 MHz, CDCl3) δ 33.42.

[0110] HRMS (ESI + m / z: [M+H] + Theoretical value: C 30 H 40 BO2 + 443.3116, Measured value: 443.3115.

[0111] IR (neat, cm -1 ): 2975, 2920, 1370, 1315, 1141, 908, 849, 732, 699.

[0112] Example 9: Tertiary borate ester IV-9

[0113]

[0114] In this embodiment, equimolar amounts of 1-(5-bromopent-1-yn-1-yl)-4-methylbenzene were used to replace the (5-bromopent-1-yn-1-yl)benzene used in Example 1. The other steps were the same as in Example 1, and the yield was 84%.

[0115] The characterization data are: 1H NMR (400 MHz, CDCl3) δ 7.31 (d, J = 8.0 Hz, 2H), 7.23 –7.17 (m, 2H), 7.13 (t, J = 7.4 Hz, 1H), 7.09 – 7.00 (m, 3H), 5.84 – 5.70 (m,1H), 5.08 – 4.90 (m, 2H), 3.18 (dd, J = 89.9, 15.4 Hz, 2H), 2.88 – 2.72 (m,2H), 2.56 – 2.38 (m, 2H), 2.32 (s, 3H), 2.22 – 2.06 (m, 2H), 1.81 – 1.63 (m,1H), 1.14 (s, 12H).

[0116] 13 C NMR (100 MHz, CDCl3) δ 142.2, 140.7, 139.7, 137.4, 136.4, 134.5,129.3, 128.9, 128.5, 127.9, 125.5, 116.3, 83.4, 41.2, 36.9, 36.8, 36.7, 24.9,24.3, 22.14, 21.12.

[0117] 11 B NMR (128 MHz, CDCl3) δ 34.23.

[0118] HRMS (ESI + m / z: [M+H] + calcd for C 29 H 38 BO2 + 429.2959, Found: 429.2954.

[0119] IR (neat, cm -1 ): 2975, 2922, 1370, 1341, 1319, 1141, 850, 699.

[0120] Example 10: Tertiary borate ester IV-10

[0121]

[0122] In this embodiment, equimolar amounts of 1-(5-bromopent-1-yn-1-yl)-4-isopropylbenzene were used to replace the (5-bromopent-1-yn-1-yl)benzene used in Example 1, and the other steps were the same as in Example 1, with a yield of 84%.

[0123] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.38 – 7.34 (m, 2H), 7.20 – 7.15(m, 2H), 7.14 – 7.10 (m, 3H), 6.97 – 6.90 (m, 2H), 5.82 – 5.64 (m, 1H), 5.07– 4.87 (m, 2H), 3.18 (dd, J = 116.0, 15.3 Hz, 2H), 2.95 – 2.77 (m, 3H), 2.57– 2.39 (m, 2H), 2.26 – 2.05 (m, 2H), 1.78 – 1.61 (m, 2H), 1.25 (d, J = 6.9Hz, 6H), 1.15 (d, J = 2.0 Hz, 12H).

[0124] 13 C NMR (100 MHz, CDCl3) δ 145.6, 142.9, 140.7, 139.9, 137.4, 136.3,129.3, 129.0, 127.8, 125.8, 125.5, 116.2, 83.4, 41.4, 36.9, 36.8, 36.7, 33.7,24.9, 24.3, 24.2, 22.1.

[0125] 11 B NMR (128 MHz, CDCl3) δ 30.57.

[0126] HRMS (ESI + m / z: [M+H] + calcd for C 31 H 42 BO2 + 457.3272, Found: 457.3271.

[0127] IR (neat, cm -1 ): 2957, 1452, 1370, 1316, 1141, 850, 700, 673.

[0128] Example 11: Tertiary borate ester IV-11

[0129]

[0130] In this embodiment, equimolar amounts of 4-bromobutyl ether benzyl ester were used to replace the allyl bromide used in Example 1, and the other steps were the same as in Example 1, with a yield of 75%.

[0131] The characterization data are: 1 H NMR (400 MHz, CDCl3) δ 7.47–7.40 (m, 2H), 7.38–7.33 (m,4H), 7.33–7.22 (m, 3H), 7.20–7.08 (m, 4H), 7.02–6.94 (m, 2H), 4.49 (s, 2H), 3.48 (t, J = 6.9 Hz, 2H), 3.14 (dd, J = 102.9, 15.5 Hz, 2H), 2.63–2.32 (m,2H), 2.25–1.98 (m, 4H), 1.76–1.67 (m, 2H), 1.66–1.41 (m, 2H), 1.14 (s, 12H).

[0132] 13 C NMR (100 MHz, CDCl3) δ 146.0, 140.7, 140.1, 138.9, 136.6, 129.2,129.1, 128.4, 127.9, 127.81, 127.80, 127.5, 125.5, 125.2, 83.4, 72.7, 71.3,36.9, 36.8, 36.7, 33.3, 27.2, 24.8, 24.2, 22.2.

[0133] 11 B NMR (128 MHz, CDCl3) δ 32.31.

[0134] HRMS (ESI + m / z: [M+H] + calcd for C 35 H 44 BO3 + 523.3378, Found: 523.3378.

[0135] IR (neat, cm -1): 2979, 2928, 1452, 1371, 1139, 733, 697, 672.

[0136] This invention achieves rapid construction of organoboron molecular structures through a one-pot, multi-component coupling process (deborylation-metathesis-electrophilic capture). By changing the electrophilic reagent, this invention can yield a variety of products, including borate esters, geminodiaborosilanes, 1,3-dienes, and highly substituted ketones. Furthermore, this invention eliminates the need for expensive or toxic transition metal catalysts, reducing environmental pollution and purification costs.

[0137] Example 12: Application of Tertiary Borate IV

[0138] The borate ester compounds prepared by this invention exhibit excellent potential for scale-up synthesis and efficient subsequent derivatization. Under standard conditions, gram-scale scale-up reactions achieved separation yields of 75% and 73% for the target borate ester compounds (corresponding to separation yields of 0.93 g and 1.14 g, respectively), fully demonstrating the promising prospects for industrial application of this method.

[0139] Further research shows that the borate esters of this invention can achieve a variety of highly selective transformations, providing an effective route for constructing structurally diverse organic molecules. For example, when these borate esters participate in stereoselective allyl borylation reactions, they can be efficiently coupled with aldehydes to obtain high-allyl alcohol products with excellent diastereoselectivity (dr > 20:1). By controlling the oxidation system, differentiated chemoselective transformations can also be achieved: under peroxyacid conditions, the carbon-carbon double bond and the borate ester group can be simultaneously oxidized to generate epoxy alcohols; while under hydrogen peroxide conditions, the borate ester is preferentially and selectively oxidized to obtain the corresponding allyl alcohol products, such as... Figure 4 As shown in the figure. Furthermore, utilizing the high reactivity of tertiary boron esters under alkaline conditions, the synthesis of α-deuterated alkenes can be achieved efficiently, with yields reaching 91% and deuterium incorporation rates of approximately 95%. Simultaneously, using HBpin as a boron source for subsequent catalytic hydroboration reactions, 1,4-diboron compounds of significant synthetic value can be further constructed. These products can also be converted into corresponding alcohol derivatives via cyclopropanation and subsequent oxidation reactions, further expanding the application scope of this strategy in the synthesis of complex organic molecules.

[0140] Compound V-6 ( Figure 4 Using ) as a modifying agent, bisphenol A type epoxy resin (E-51) is chemically modified to prepare carbon fiber reinforced composite materials with high toughness and high heat resistance.

[0141] Compound V-6 and isophorone diisocyanate (IPDI) were added to acetone at a molar ratio of 1:1.5 and reacted under nitrogen protection at 60°C. Then, epoxy resin E-51 was added, and the acetone was removed under vacuum at 80°C with stirring to obtain a modified epoxy resin matrix. Methyltetrahydrophthalic anhydride (epoxy group: anhydride group molar ratio of 1:1) and 0.5 wt% DMP-30 accelerator were added, stirred evenly, and then degassed under vacuum for 15 min to obtain the modified resin. The modified resin was injected into a carbon fiber preform, mixed evenly, and then heated at 80°C for 1 h, 120°C for 2 h, and 150°C for 3 h. After natural cooling to room temperature, the preform was demolded to obtain a composite laminate.

[0142] Carbon fiber composite materials were prepared using pure epoxy resin without V-6 and following the same process, serving as a performance comparison sample.

[0143] The interlaminar shear strength and impact strength of the composite laminate are both at least 10% higher than those of the unmodified control sample, and the water absorption is reduced by at least 8%. This is because the cyclopropyl and aryl side chains in compound V-6 can penetrate into the micro-defects on the carbon fiber surface, strengthening the resin-fiber interface bonding through van der Waals forces and preventing interlaminar delamination failure.

[0144] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0145] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An organoboron compound prepared by a boroolefin / alkyne metathesis method, characterized in that, The structural formula of the organoboron compound is shown in Formula IV: ； In Equation IV, R 1 Selected from unsubstituted alkyl, substituted alkyl, unsubstituted aryl, or substituted aryl, R 2 The compound is selected from unsubstituted alkyl, substituted alkyl, unsubstituted aryl, substituted aryl, unsubstituted heteroaryl, substituted heteroaryl, or trimethylsilyl, and E is selected from unsubstituted alkyl, substituted alkyl, unsubstituted aryl, substituted aryl, or carbonyl compounds.

2. The organoboron compound prepared according to claim 1 based on the boroolefin / alkyne metathesis method, characterized in that, R 1 Selected from C1-C 20 Straight chain, C1-C 20 Branched alkyl groups, C3-C 20 The cycloalkyl, unsubstituted aryl, or substituted aryl group, wherein the substituent on the aryl group is selected from one or more of halogens, C1-C6 alkyl groups, C1-C6 alkoxy groups, and trifluoromethyl groups; R 2 Selected from unsubstituted aryl, substituted aryl, unsubstituted heteroaryl, substituted heteroaryl, C1-C 12 The alkyl or trimethylsilyl group, wherein the substituents on the aryl group are selected from C1-C6 alkyl, C1-C6 alkoxy, halogen, cyano, ester or aryl groups.

3. A method for preparing the organoboron compound as described in claim 1, characterized in that, Includes the following steps: The 1,1,1-triborylalkane shown in Formula I and the alkyne shown in Formula II were mixed with a base and subjected to a boroalkene / alkyne metathesis reaction. Then, the electrophilic reagent shown in Formula III was added for capture to obtain organoboron compound IV. ； Among them, R 1 Selected from alkyl, alkyl derivatives, aryl or aryl derivatives, R 2 The reagent is selected from alkyl, alkyl derivatives, aryl or aryl derivatives, and E is selected from alkyl, alkyl derivatives, aryl, aryl derivatives or carbonyl compounds; the electrophilic reagent is selected from haloalkanes, chlorosilanes, water, aldehydes or esters.

4. The method for preparing the organoboron compound according to claim 3, characterized in that, Under inert gas protection, 1,1,1-triborylalkanes of Formula I and alkynes of Formula II are mixed with a base in an organic solvent to carry out a boroolefin / alkyne metathesis reaction. The organic solvent is an ether solvent, an aromatic hydrocarbon solvent, or a polar aprotic solvent.

5. The method for preparing the organoboron compound according to claim 4, characterized in that, The organic solvent is tetrahydrofuran, 2-methyltetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, or toluene.

6. The method for preparing the organoboron compound according to any one of claims 3 to 5, characterized in that, The molar ratio of the 1,1,1-triborylalkane, alkyne compound, and base is 1–2:1:2–5.

7. The method for preparing the organoboron compound according to claim 6, characterized in that, The alkali is selected from potassium tert-butoxide, sodium tert-butoxide, lithium tert-butoxide, sodium hydride, or potassium bis(trimethylsilyl)amino.

8. The method for preparing the organoboron compound according to claim 6, characterized in that, The reaction temperature for the metathesis reaction is 60–120 °C, and the reaction time is 0.5–12 h.

9. The method for preparing the organoboron compound according to claim 6 or 8, characterized in that, The molar ratio of the alkyne compound represented by Formula II to the electrophilic reagent is 1:1 to 3; the reaction temperature of the electrophilic reagent capture stage is -20℃ to 30℃, and the capture time is 0.1 to 2 h.

10. The application of an organoboron compound prepared by the boroolefin / alkyne metathesis method as described in claim 1 as an intermediate in functional materials.

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