1, 4-diaza-butantriene compound as well as synthesis method and application of 1, 4-diaza-butantriene compound

Abstract

The invention provides a 1, 4-diaza-butanetriene compound as well as a synthesis method and application thereof, and belongs to the technical field of organic synthesis. The preparation method comprises the following steps: carrying out a first reaction on a compound 1 and a compound 2 in a solvent A, removing the solvent A after the reaction is finished, extracting with benzene or toluene, filtering, mixing with 12-crown ether-4, and stirring to obtain a compound 3; the synthesis method of the compound 3 provided by the invention is high in yield, simple to operate, mild in reaction, simple in required reaction condition control and high in speed. The obtained compound 3 has excellent stability and can be used for key intermediates in various organic reactions, such as preparation of alpha-diimine ligands.

Description

Technical Field

[0001] This invention belongs to the field of chemical synthesis technology, specifically relating to a 1,4-diazabuttriene compound, its synthesis method, and its application. Background Technology

[0002] A full century after Lieke synthesized the first isonitrile in 1959, it wasn't until 1958 that Grundmann first proposed that the head-to-head dimerization of two isonitrile molecules could produce the transient intermediate 1,4-diazabutatriene, with the structure Ph–N=C=C=N–Ph. Since then, 1,4-diazabutatrienes have been considered key intermediates in many organic reactions; however, due to their thermodynamic instability, no one has yet successfully synthesized this important organic intermediate experimentally.

[0003] Therefore, there is still an urgent need for a 1,4-diazabuttriene compound with good thermodynamic stability and high yield, as well as its synthesis method. Summary of the Invention

[0004] To address the aforementioned technical problems, the present invention provides the following technical solutions.

[0005] In a first aspect, the present invention provides a method for synthesizing compound 3.

[0006] A method for synthesizing compound 3, comprising: , Compound 1 and Compound 2 were reacted in solvent A. After the reaction was completed, solvent A was removed, and the mixture was extracted with benzene or toluene, filtered, and the filtrate was mixed with 12-crown ether-4 and stirred to obtain compound 3. Wherein, the Dipp group represents The TMS group represents trimethylsilyl, and the 12-C-4 in compound 3 represents 12-crown ether-4.

[0007] In some embodiments, in the first reaction, the molar ratio of compound 1 to compound 2 is 1:2 to 1:3. In some embodiments, in the first reaction, the molar ratio of compound 1 to compound 2 is 1:2.

[0008] In some embodiments, solvent A comprises tetrahydrofuran. Extensive screening and investigation have revealed that, compared to other solvents, using tetrahydrofuran as solvent A is more conducive to the first reaction and to increasing the yield of compound 3. Using other solvents may lead to the inability of the first reaction to proceed or a significant decrease in product yield.

[0009] In some embodiments, 0.05 mmol to 0.5 mmol of compound 1 is added per 1 ml of solvent A. In some embodiments, 0.05 mmol, 0.1 mmol, 0.15 mmol, 0.16 mmol, 0.17 mmol, 0.2 mmol, 0.25 mmol, 0.3 mmol, 0.35 mmol, 0.4 mmol, 0.45 mmol, 0.5 mmol, or any value within the range of any two of these values ​​are added per 1 ml of solvent A.

[0010] In some embodiments, the method for synthesizing compound 3 further includes drying after the first reaction is completed.

[0011] In some embodiments, the drying process in the synthesis of compound 3 includes vacuum drying.

[0012] In some embodiments, the molar ratio of 12-crown ether-4 to compound 1 is 1:1 to 1:1.5. In some embodiments, the molar ratio of 12-crown ether-4 to compound 1 is 1:1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, or any value within the range of any two of these values.

[0013] In some embodiments, the stirring time is 0.5 hours to 5 hours. In some embodiments, the stirring time is 0.5 hours, 1 hour, 1.5 hours, 2 hours, 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, or any value within a range of any two of these values.

[0014] In some embodiments, the synthesis method further includes a first post-treatment after stirring, the first post-treatment including: removing solvent, washing, and drying.

[0015] In some embodiments, solvent removal in the first post-processing includes solvent removal using reduced pressure.

[0016] In some embodiments, the washing in the first post-processing includes washing with n-pentane or n-hexane.

[0017] Secondly, the present invention provides a method for synthesizing compound Ia.

[0018] A method for synthesizing compound Ia, comprising: , Compound 3 reacts with an alkyl iodide in solvent B to give compound Ia; Among them, R 1 It is a C1~C10 straight-chain alkyl or a C3~C10 branched alkyl.

[0019] In some embodiments, R 1 It can be methyl, ethyl, C3 straight-chain alkyl, C4 straight-chain alkyl, C5 straight-chain alkyl, C6 straight-chain alkyl, C7 straight-chain alkyl, C8 straight-chain alkyl, C9 straight-chain alkyl, or C10 straight-chain alkyl.

[0020] In some embodiments, R 1 It can be a C3 branched alkyl, C4 branched alkyl, C5 branched alkyl, C6 branched alkyl, C7 branched alkyl, C8 branched alkyl, C9 branched alkyl, or C10 branched alkyl.

[0021] In some embodiments, R 1 It is isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3,4-dimethylpentyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3,5-dimethylhexyl or 4,4-dimethylhexyl.

[0022] In some embodiments, the R 1 It can be methyl or ethyl.

[0023] In some embodiments, solvent B includes at least one of benzene, toluene, diethyl ether, tetrahydrofuran, deuterated benzene, and deuterated toluene.

[0024] In some embodiments, the molar ratio of compound 3 to the alkyl iodide is 1:1 to 1:3. In some embodiments, the molar ratio of compound 3 to the alkyl iodide is 1:1, 1:1.5, 1:2, 1:2.5, 1:3, or any value within the range of any two of these values.

[0025] In some embodiments, in the second reaction, 0.02 mmol to 0.06 mmol of compound 3 is added per 1 ml of solvent B. In some embodiments, in the second reaction, 0.02 mmol, 0.03 mmol, 0.04 mmol, 0.05 mmol, 0.06 mmol of compound 3, or any value within the range of any two of these values, are added per 1 ml of solvent B.

[0026] In some embodiments, the duration of the second reaction is 2 to 10 minutes. In some embodiments, the duration of the second reaction is 2 minutes, 2.5 minutes, 3 minutes, 3.5 minutes, 4 minutes, 4.5 minutes, 5 minutes, 5.5 minutes, 6 minutes, 6.5 minutes, 7 minutes, 7.5 minutes, 8 minutes, 8.5 minutes, 9 minutes, 9.5 minutes, 10 minutes, or any value within a range of any two of these values.

[0027] In some embodiments, the method for synthesizing compound Ia further includes synthesizing compound 3 according to the method for synthesizing compound 3 according to the first aspect.

[0028] Thirdly, the present invention provides a method for synthesizing compound IIa.

[0029] A method for synthesizing compound IIa, characterized by comprising: , Compound Ia was obtained according to the synthetic method of compound Ia described in the second aspect, and then allowed to stand to spontaneously carry out a dimerization reaction to obtain compound IIa; In some embodiments, the method for synthesizing compound IIa further includes removing solvent B under reduced pressure after the dimerization reaction.

[0030] In some embodiments, the resting time is 10 to 30 hours. In some embodiments, the resting time is 10 hours, 11 hours, 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours, 18 hours, 19 hours, 20 hours, 21 hours, 22 hours, 23 hours, 24 hours, 25 hours, 26 hours, 27 hours, 28 hours, 29 hours, 30 hours, or any value within a range of any two of these values.

[0031] Fourthly, the present invention provides a compound.

[0032] A compound selected from compounds with the following structures: , , , , , , , , , , Wherein, the Dipp group represents The TMS group represents a trimethylsilyl group; In compound Ia, R 1Selected from C1~C10 straight-chain alkyl or C3~C10 branched alkyl; In compound IIa, R 1 Selected from C1~C10 straight-chain alkyl or C3~C10 branched alkyl; In compound 3, 12-C-4 represents 12-crown ether-4.

[0033] In some embodiments, R in compound Ia 1 It can be methyl, ethyl, C3 straight-chain alkyl, C4 straight-chain alkyl, C5 straight-chain alkyl, C6 straight-chain alkyl, C7 straight-chain alkyl, C8 straight-chain alkyl, C9 straight-chain alkyl, or C10 straight-chain alkyl.

[0034] In some embodiments, R in compound Ia 1 It can be a C3 branched alkyl, C4 branched alkyl, C5 branched alkyl, C6 branched alkyl, C7 branched alkyl, C8 branched alkyl, C9 branched alkyl, or C10 branched alkyl.

[0035] In some embodiments, R in compound Ia 1 It is isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3,4-dimethylpentyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3,5-dimethylhexyl or 4,4-dimethylhexyl.

[0036] In some embodiments, R in compound Ia 1 It can be methyl or ethyl.

[0037] In some embodiments, R in compound IIa 1 It can be methyl, ethyl, C3 straight-chain alkyl, C4 straight-chain alkyl, C5 straight-chain alkyl, C6 straight-chain alkyl, C7 straight-chain alkyl, C8 straight-chain alkyl, C9 straight-chain alkyl, or C10 straight-chain alkyl.

[0038] In some embodiments, R in compound IIa 1 It can be a C3 branched alkyl, C4 branched alkyl, C5 branched alkyl, C6 branched alkyl, C7 branched alkyl, C8 branched alkyl, C9 branched alkyl, or C10 branched alkyl.

[0039] In some embodiments, R in compound IIa1 It is isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, 2-methylpentyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 3,3-dimethylpentyl, 3,4-dimethylpentyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3,5-dimethylhexyl or 4,4-dimethylhexyl.

[0040] In some embodiments, R in compound IIa 1 It can be methyl or ethyl.

[0041] In some embodiments, in compound Ia or compound IIa, R 1 Each is independently selected from methyl or ethyl.

[0042] Fifthly, the present invention provides an application of the compound described in the fourth aspect.

[0043] The use of one of the aforementioned compounds IIa, 8, 9, 10, 11 or 12 as a ligand in the Suzuki reaction.

[0044] In a sixth aspect, the present invention provides an application of the aforementioned compound 6 or compound 7.

[0045] The use of compound 6 or compound 7 of the compounds described in the fifth aspect as a precursor in the reaction for preparing transition metal complex ligands.

[0046] In some embodiments, the reaction for preparing the transition metal complex ligand includes: reacting compound 6 or compound 7 with the first transition metal complex in a first solvent, filtering, removing the solvent from the filtrate, washing, and drying to obtain the transition metal complex ligand.

[0047] In some embodiments, the first transition metal complex includes [(COD)IrCl]2 and / or [(CO)2RhCl]2.

[0048] In some embodiments, the first solvent includes at least one of benzene, deuterated benzene, toluene, diethyl ether, and tetrahydrofuran.

[0049] In some embodiments, the transition metal complex ligand includes compound 8 or compound 9.

[0050] In some embodiments, the washing is performed using n-pentane.

[0051] In some embodiments, the drying process in the reaction for preparing transition metal complex ligands includes vacuum drying.

[0052] Beneficial effects One embodiment of the present invention includes at least one of the following beneficial effects: (1) This invention employs a suitable strategy to synthesize the first 1,4-diazabuttriene compound through isonitrile dimerization, filling a long-standing gap in the field of isonitrile chemistry. At the same time, this invention conducts in-depth exploration of the unique structure and reactivity of 1,4-diazabuttriene compounds, discovering their great potential in constructing nitrogen-carbon skeletons.

[0053] (2) This invention designs and synthesizes a sterically hindered boron-substituted aminoisocyanate, which spontaneously undergoes dimerization at room temperature, thereby synthesizing the first 1,4-diazabuttriene compound. This 1,4-diazabuttriene compound is stable at room temperature and exhibits excellent stability. Subsequent studies have shown that the C=C bonding mode in the N=C=C=N of the 1,4-diazabuttriene compound differs from that of ordinary C=C double bonds, which also gives it unique reactivity in coordination and addition reactions.

[0054] (3) The synthesis method of compound 3 provided by the present invention has high yield, simple operation, mild reaction, simple control of required reaction conditions, and fast speed.

[0055] (4) Compound 3 provided by the present invention can be used as a key intermediate in a variety of organic reactions, for example, for the preparation of α-diimine ligands.

[0056] (5) The application of compounds IIa, 8, 9, 10, 11 or 12 provided by the present invention as ligands in the Suzuki reaction is beneficial to improving the product yield of the Suzuki reaction and has excellent activity.

[0057] (6) Compound 6 and / or Compound 7 provided by the present invention can serve as precursors for bisisonitrile compounds, providing two isonitrile ligands for the transition metal center. The resulting transition metal complexes can further participate in a variety of catalytic reactions. The transition metal complexes prepared using Compound 6 and / or Compound 7 provided by the present invention have high yields and the resulting transition metal complexes have excellent activity (such as excellent activity as ligands in the Suzuki reaction).

[0058] Terminology Explanation Unless otherwise stated, the following terms and phrases as used herein are intended to have the following meanings: The term "multiple" means two or more, such as two, three, four or five.

[0059] In this invention, "room temperature" (rt) refers to ambient temperature, ranging from approximately 10°C to approximately 40°C. In some embodiments, "room temperature" refers to a temperature ranging from approximately 15°C to approximately 35°C; in some embodiments, "room temperature" refers to a temperature ranging from approximately 20°C to approximately 30°C; in some embodiments, "room temperature" refers to a temperature ranging from approximately 20°C to approximately 35°C; in other embodiments, "room temperature" refers to a temperature ranging from approximately 25°C to approximately 30°C; in other embodiments, "room temperature" refers to a temperature ranging from approximately 22°C to approximately 28°C; in other embodiments, "room temperature" refers to a temperature ranging from approximately 24°C to approximately 26°C; and in still other embodiments, "room temperature" refers to 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc.

[0060] The term “and / or” should be understood to mean any one of the options or any combination of two or more of the options.

[0061] The terms "optional" or "optionally" refer to an event or situation that may, but is not necessarily, occur, as described below, and the description includes both the possibility that the event or situation occurs and the possibility that it does not occur. For example, "optionally condensing agent" means that a condensing agent may or may not be present.

[0062] The term "heteroatom" refers to an oxygen atom, a nitrogen atom, or a sulfur atom.

[0063] The term "halogen" refers to a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0064] In the foregoing description of this invention, all figures disclosed herein, whether or not the words “approximately” or “about” are used, are approximate values. Based on the disclosed figures, the value of each figure may vary by less than ±10% or by a difference that is considered reasonable by those skilled in the art, such as ±1%, ±2%, ±3%, ±4%, or ±5%.

[0065] The term "v / v" indicates a volume ratio.

[0066] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0067] "Aryl" refers to an aromatic hydrocarbon group derived by removing a hydrogen atom from a single carbon atom in a parent aromatic ring system. Typical aryl groups include, but are not limited to, groups derived from benzene (e.g., phenyl), substituted benzenes, naphthalenes, anthracene, biphenyls, and similar groups.

[0068] The term "substituted" refers to alkyl, aryl, arylalkyl, heterocyclic, heteroaryl, carbocyclic, etc., such as "substituted C1-C". 10 Alkyl, substituted C6-C 20 "Aryl", "Substituted arylalkyl", "Substituted C1-C" 20 "Heterocyclic" and "substituted carbocyclic" refer to C1-C rings in which one or more hydrogen atoms are independently replaced by non-hydrogen substituents, respectively. 10 Alkyl, C6-C 20 Aryl, arylalkyl, C1-C 20 Heterocyclic, carbocyclic. Unless otherwise stated, when the term “substituted” is used in conjunction with a group having two or more moieties capable of substitution, such as an arylalkyl group, the substituent may be attached to the aryl moieties, alkyl moieties, or both.

[0069] "Heteroaryl" refers to an aromatic heterocyclic group having at least one heteroatom in the ring. Non-limiting examples of suitable heteroatoms that can be included on an aromatic ring include oxygen, sulfur, and nitrogen. Non-limiting examples of heteroaryl rings include all those aromatic rings listed in the definition of "heterocyclic group," including pyridinyl, pyrroloyl, oxazolyl, indolyl, isoydinolyl, purinyl, furanyl, thiophenyl, benzofuranyl, benzothiophenyl, carbazoyl, imidazoyl, thiazoyl, isoxazolyl, pyrazolyl, isothiazolyl, quinolinyl, isoquinolinyl, pyridazinyl, pyrimidinyl, pyrazolyl, etc.

[0070] The group "Ph" represents phenyl. The group "Boc" represents tert-butyloxycarbonyl. The group "Bz" represents benzoyl. The group "Me" represents methyl. The group "Et" represents ethyl. The group "Ac" represents acetyl. The group "Cbz" represents benzyloxycarbonyl. The group "nBu" represents n-butyl. The group "tBu" represents tert-butyl. The group "Bn" represents benzyl. The group "Dipp" represents... The TMS group represents trimethylsilyl. 12-C-4 represents 12-crown ether-4 (CAS number 294-93-9).

[0071] In this invention, "mmol" represents millimole; "mol" represents mole; "g" represents gram; and "mg" represents milligram. "eq" or "equiv" represents equivalent, a unit used to express the molar ratio between reactants; it does not directly correspond to a specific number of moles or mass, but rather uses the amount (molar quantity) of a key reactant as a benchmark to measure the relative amounts of other reactants. "L" represents liter; "mL" represents milliliter; "μl" represents microliter; "°C" represents degree Celsius; and "h" represents hour.

[0072] In the compounds provided by this invention (such as compounds 8 and 9), the arrow "→" indicates a coordinate bond, and the direction of the arrow indicates the direction of electron pair donation, that is, lone electron pair donor atom of the ligand → electron pair acceptor atom.

[0073] In compound 9 of this invention, the dashed line connecting "Ir" represents a coordination bond, which coordinates with "Ir" through the π electron cloud of the carbon-carbon double bond.

[0074] In this invention, the colon ":" in compounds 2, 3, 4, 5, 8, and 9 represents a lone pair of electrons.

[0075] The right angle next to Li in compound 3 of this invention "" indicates a separator between cations and anions, not a structural component, used only to distinguish ion boundaries. In the solid form of compound 3 (such as crystals or amorphous powders), Li will coordinate with the terminal C atom with a lone pair of electrons, i.e. .

[0076] In compound 3 of this invention, the four oxygen atoms on the 12-C-4 ring all contain lone pairs of electrons, which are all oriented toward the center of the ring cavity, and coordinate with Li through coordination. + Combined, Li + The lone pair of electrons from four oxygen atoms simultaneously interacts with the center of the ring cavity of the embedded crown ether. + The empty orbitals interact to form a cage-like chelate structure.

[0077] The Suzuki reaction, also known as the Suzuki-Miyaura reaction, is a relatively new organic coupling reaction in which aryl or alkenylboronic acids or boronic esters are cross-coupled with chlorinated, bromine, or iodoaryl hydrocarbons or alkenes under the catalysis of zero-valent palladium complexes. First reported by Akira Suzuki in 1979, this reaction has wide applications in organic synthesis, exhibiting strong substrate adaptability and functional group tolerance. It is commonly used to synthesize polyenes, styrene, and biphenyl derivatives, thus finding applications in the synthesis of numerous natural products and organic materials. Detailed Implementation

[0078] To enable those skilled in the art to better understand the technical solutions of the present invention, some non-limiting embodiments are further disclosed below to provide a more detailed description of the present invention.

[0079] All reagents used in this invention can be purchased commercially or prepared by the methods described in this invention.

[0080] Tetrahydrofuran, toluene, benzene, diethyl ether, hexamethyldisiloxane, deuterated benzene, and deuterated tetrahydrofuran are all used in sealed bottles containing 3A-grade molecular sieves after moisture removal.

[0081] The Chinese meanings of the abbreviations or chemical formulas of the reagents used in this invention: Tetrahydrofuran (THF), Toluene (Tol), Benzene (C6H6), Diethyl ether (Et2O), Hexamethyldisiloxane ([TMS]2O), Deuterated benzene (C6D6), Deuterated tetrahydrofuran (THF-d8), Methanol (MeOH), Ethanol (EtOH), Tetrahydrofuran (THF), 1,5-cyclooctadiene iridium chloride dimer (CAS No.: 12112-67-3; Abbreviation: [(COD)IrCl]2), Dicarbonyl rhodium chloride dimer (CAS No.: 14523-22-9; Abbreviation: [(CO)2RhCl]2).

[0082] Example 1: Synthesis of Compound 3

[0083] A solution of compound 2 (0.94 mmol) in tetrahydrofuran (3.0 mL) was slowly added dropwise to a solution of compound 1 (0.47 mmol) in tetrahydrofuran (3.0 mL) at room temperature to obtain a mixture. The mixture was stirred at room temperature for 1 hour, and the solvent was removed under reduced pressure. The mixture was extracted with benzene, and the remaining insoluble solid was discarded. The mixture was then filtered through diatomaceous earth to obtain a filtrate. This filtrate was mixed with 12-crown ether-4 (0.47 mmol), stirred for 30 minutes, and the solvent was removed under reduced pressure to obtain a solid. The solid was washed with n-pentane (2 mL × 3 times) and dried to obtain compound 3 (0.32 mmol, white solid). Characterization data for compound 3 are as follows: 1 H NMR (600 MHz, THF-d8, 298 K): δ(ppm) = 6.96 (br, 6H, Ar- H ), 3.63(sept, 3 J HH = 6.9 Hz, 4H, C H (CH3)2), 3.58 (br, 16H, OC H 2C H 2O, overlapped withTHF), 3.33 (s, 4H, NC H 2C H 2N), 1.27 (d, 3 J HH = 6.9 Hz, 12H, CH(C H 3)2), 1.23 (d, 3 J HH = 6.9 Hz, 12H, CH(C H 3)2). 13 C{ 1 H} NMR (151 MHz, THF-d8, 298 K): δ(ppm) = 149.0 (Ar- C ), 144.3(Ar- C ), 125.6 (Ar- C ), 123.6 (Ar- C ), 110.0 (BNN C ), 71.6 (O C H2 C H2O), 53.7 (N) C H2C H2N), 29.1 ( C HMe2), 25.3 (CH Me 2), 25.3 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, THF-d8, 298 K): δ(ppm) = 25.88 (br). HRMS(m / z): [M-Li(12-C-4)] - calcd. for C 27 H 38 N4B - : 429.31950, found:429.31949. Example 2: Synthesis of Compound 6

[0084] CH3I (0.049 mmol) was added to a C6D6 solution (1.0 mL) of compound 3 (0.049 mmol); after stirring at room temperature for 2 minutes, the solution was filtered through glass filter paper to obtain a colorless solution of compound 4. After standing for 24 hours, the solvent was removed under reduced pressure to obtain compound 6 (yellow-green solid, 0.024 mmol).

[0085] Characterization data of compound 4: 1 H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.17-7.20 (m, 2H, Ar- H ), 7.08-7.13 (m, 4H, Ar- H ), 3.47 (sept, 3 J HH = 6.9 Hz, 4H, C H Me2), 3.35 (s, 4H, NC) H 2C H 2N), 2.24 (s, 3H, N Me ), 1.34 (d, 3 J HH = 6.9 Hz, 12H, CH Me 2), 1.27 (d, 3 J HH= 6.9 Hz, 12H, CH Me 2). 13 C{ 1 H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 147.4 (Ar- C ), 139.2 (Ar- C ), 136.6 (N C ), 127.6 (Ar- C ), 124.3 (Ar- C ), 52.9 (N C H2 C H2N), 40.5 (N Me ), 28.7( C HMe2), 25.2 (CH Me 2), 24.2 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 23.4 (br). HRMS(m / z): [M+H] + calcd. for C 28 H 42 N4B: = 445.34970, found: 445.34845. Characterization data of compound 6: 1 H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.04-7.11 (m, 12H, Ar- H ), 3.55(sept, 3 J HH = 6.9 Hz, 8H, C H Me2), 3.44 (s, 8H, NC H 2C H 2N), 2.32&2.41 (s, 6H,N Me ), 1.27-1.29 (m, 24H, CH Me 2), 1.14-1.16 (m, 24H, CH Me 2). 13 C{ 1H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 164.59&161.48 (N CC N), 147.13 & 147.00 (Ar- C ), 141.21&141.12 (Ar- C ), 126.88 & 126.75 (Ar- C ), 124.01&123.93 (Ar- C ), 53.24&53.19 (N C H2 C H2N), 37.59 & 37.06 (N Me ), 28.62 ( C HMe2), 25.07 & 25.06 (CH Me 2), 24.09 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 25.8 (br). Note: Due to the Z / E isomerism of the N=C=C=N portion of compound 6, its... 1 H and 13 C{ 1 Two different signals were observed in the H NMR spectrum.

[0086] HRMS(m / z): [M+H] + calcd. for C 56 H 83 N8B2: = 889.69213, found: 889.69092. Example 3: Synthesis of Compound 7

[0087] CH3CH2I (0.049 mmol) was added to a C6D6 solution (1.0 mL) of compound 3 (0.049 mmol); after stirring at room temperature for 2 minutes, the solution was filtered through glass filter paper to obtain a colorless solution of compound 5. After standing for 24 hours, the solvent was removed under reduced pressure to obtain compound 7 (yellow-green solid, 0.023 mmol).

[0088] Characterization of compound 5: 1H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.17-7.20 (m, 2H, Ar- H ), 7.11-7.13 (m, 4H, Ar- H ), 3.52 (sept, 3 J HH = 6.9 Hz, 4H, C H Me2), 3.38 (s, 4H,NC H 2C H 2N), 2.55 (q, 2H, NC H 2CH3, overlapped with CH3CH2I), 1.36 (d, 3 J HH = 6.9Hz, 12H, CH Me 2), 1.27 (d, 3 J HH = 6.9 Hz, 12H, CH Me 2), 0.76 (t, 3 J HH = 6.6 Hz, 3H, NCH2C H 3). 13 C{ 1 H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 147.40 (Ar- C ), 139.37 (Ar- C ), 138.06 (N C ), 127.60 (Ar- C ), 124.30 (Ar- C ), 52.98 (N C H2 C H2N), 46.22(N C H2CH3), 28.66 ( C HMe2), 25.40 (CH Me 2), 24.25 (CH Me 2), 12.55 (NCH2 C H3). 11 B{ 11H NMR (193 MHz, C6D6, 298 K): δ(ppm) = 23.4 (br). HRMS(m / z): [M+H] + calcd. for C 29 H 44 N4B: = 459.36535, found: 459.36490. Characterization of Compound 7: 1 1H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.09 - 7.12 (m, 4H, Ar- H ), 7.05 - 7.06 (m, 8H, Ar- H ), 3.60 (sept, 3 J HH = 6.9 Hz, 8H, C H Me2), 3.47 (s, 8H,NC H 2C H 2N), 2.92&2.84 (q, 3 J HH = 6.6 Hz, 4H, NC H 2 CH3), 1.27 (d, 3 J HH = 6.9 Hz,24H, CH Me 2), 1.18 (d, 3 J HH = 6.9 Hz, 24H, CH Me 2), 0.65&0.56J (t, 3 J HH = 6.6 Hz,6H, NCH2C H 3). 13 13C{ 1 1H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 164.44&159.79 (N CC N),147.25&147.12 (Ar- C ), 141.28&141.08 (Ar- C), 126.82&126.64 (Ar- C ), 124.00 & 123.87 (Ar- C ), 53.32&53.22 (N C H2 C H2N), 44.74 (N C H2CH3), 28.60 & 28.57 ( C HMe2), 25.40 (CH Me 2), 24.16 (CH Me 2), 13.19 & 13.04 (NCH2) C H3). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 25.9 (br). Note: Due to the Z / E isomerism of the N=C=C=N portion of compound 7, its... 1 H and 13 C{ 1 Two different signals were observed in the H NMR spectrum.

[0089] HRMS(m / z): [M+H] + calcd. for C 58 H 87 N8B2: = 917.72343, found: 917.72266. Example 4: Reaction of 1,4-diazabuttriene compound 6 with [(CO)2RhCl]2

[0090] A C6D6 solution (0.2 mL) of [(CO)₂RhCl]₂ (0.017 mmol) was added to a C6D6 solution (0.5 mL) of compound 6 (0.034 mmol) at room temperature. The mixture was stirred for 24 hours, filtered through glass filter paper, and the filtrate was collected. The solvent was removed under reduced pressure, and the mixture was washed with n-pentane (0.2 mL × 3), dried, and yielded a pale compound 8 (0.031 mmol, green solid). (The "-CO" in the reaction equation indicates that [(CO)₂RhCl]₂ loses one CO atom during the reaction). Compound 8 was characterized as follows: 1 H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.23-7.27 (m, 4H, Ar- H), 7.12-7.14 (m, 8H, Ar- H ), 3.38 (sept, 3 J HH = 6.9 Hz, 8H, C H Me2), 3.29 (s, 8H,NC H 2C H 2N), 2.32 (s, 6H, N Me ), 1.31 (d, 3 J HH = 6.9 Hz, 24H, CH Me 2), 1.23 (d, 3 J HH = 6.9 Hz, 24H, CH Me 2). 13 C{ 1 H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 183.9 (d, 1 J RhC = 70.8 Hz, C O) 147.2 (Ar- C ), 138.6 (Ar- C ), 128.1 (Ar- C , overlapped with C6D6), 125.1 (d, 1 J RhC = 59.9 Hz, N C ), 124.6 (Ar- C ), 52.8 (N C H2 C H2N), 41.2 (N Me ), 28.7 ( C HMe2),25.1 (CH Me 2), 24.4 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 23.1 (br). HRMS(m / z): [M-Cl] +calcd. for C 57 H 82 N8B2ORh: = 1019.58473, found:1019.58434. Example 5: Reaction of 1,4-diazabuttriene compound 6 with [(COD)IrCl]2

[0091] A C6D6 solution (0.3 mL) of [(COD)IrCl]2 (0.034 mmol) was added to a C6D6 solution (0.5 mL) of compound 6 (0.034 mmol) at room temperature. After stirring for 15 minutes, the mixture was filtered through glass filter paper, and the filtrate was collected. The solvent was removed under reduced pressure, and the mixture was washed with n-pentane (0.2 mL × 3), dried, and compound 9 (0.028 mmol, orange solid) was obtained. Compound 9 was characterized as follows: 1 H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.15-7.17 (m, 2H, Ar- H ,overlapped with C6D6), 7.04-7.05 (m, 4H, Ar- H ), 5.23-5.25 (m, 2H, COD-C H ),3.36 (sept, 3 J HH = 6.9 Hz, 4H, C H Me2), 3.26 (s, 4H, NC H 2C H 2N), 2.87-2.88 (m,2H, COD-C H ), 2.57 (s, 3H, N Me ), 2.02-2.07 (m, 2H, COD-C H 2), 1.91-1.95 (m, 2H, COD-C) H 2), 1.54-1.60 (m, 4H, COD-C H 2), 1.25 (d, 3 J HH = 6.9 Hz, 12H, CH Me 2), 1.22(d, 3 J HH= 6.9 Hz, 12H, CH Me 2). 13 C{ 1 H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 147.3 (Ar- C ), 138.9 (Ar- C ), 136.2 (N C ), 127.6 (Ar- C ), 124. 3 (Ar- C ), 94.8 (COD- C H), 54.2 (COD- C H), 52.9 (N C H2 C H2N), 44.1 (N Me ), 33.6 (COD- C H2), 29.6 (COD- C H2), 28.7 ( C HMe2), 25.0(CH Me 2), 24.4 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 22.6 (br). HRMS(m / z): [M-Cl] + calcd. for C 36 H 53 N4BIr: 745.39870, found: 745.39692. Example 6: Reaction of 1,4-diazabuttriene compound 6 with I2

[0092] A toluene solution (0.5 mL) of I2 (0.034 mmol) was slowly added dropwise to a toluene solution (0.5 mL) of compound 6 (0.034 mmol). After stirring for 2 hours, the solution was collected by filtration through glass filter paper, and the solvent was removed under reduced pressure. The resulting solid was dissolved in 1 mL of n-pentane, and the pentane solution was concentrated and recrystallized at room temperature. After drying, compound 10 (0.028 mmol, yellow solid) was obtained. The characterization of compound 10 is as follows: 1H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.10 (br, 12H, Ar- H ), 3.62(sept, 3 J HH = 6.9 Hz, 8H, C H Me2), 3.44 (s, 8H, NC H 2C H 2N), 2.83 (s, 6H, N Me ),1.340 (d, 3 J HH = 6.9 Hz, 24H, CH Me 2), 1.30 (d, 3 J HH = 6.9 Hz, 24H, CH Me 2). 13 C{ 1 H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 147.0 (Ar- C ), 141.6 (Ar- C ), 126.9 (Ar- C ), 124.4 (Ar- C ), 100.7(N C I), 53.5 (N C H2 C H2N), 38.4 (N Me ), 28.5(CH Me 2), 25.7 (CH Me 2), 24.4 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 24.9 (br). HRMS(m / z): [MH] - calcd. for C 56 H 81 N8B2I2: 1141.48651, found:1141.48693. Example 7: Reaction of 1,4-diazabuttriene compound 6 with HCl

[0093] A 2 mol / L HCl solution in diethyl ether (16.9 μL, 0.034 mmol) was slowly added to a 0.5 mL solution of compound 6 (0.034 mmol) in C6D6 at room temperature. After stirring for 15 minutes, the solvent was removed under reduced pressure to obtain compound 11 (0.032 mmol, white solid). Compound 11 was characterized as follows: 1 H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.16 (br, 6H, Ar- H , overlapped with C6 H 6), 6.95 (br, 6H, Ar- H ), 5.60 (s, 1H NC H ), 3.60 (sept, 3 J HH = 6.9 Hz, 4H, C H Me2), 3.48 (sept, 3 J HH = 6.9 Hz, 4H, C H Me2), 3.46 (s, 4H, NC H 2C H 2N), 3.38(s, 4H, NC H 2C H 2N), 2.77 (s, 3H, N Me ), 2.40 (s, 3H, N Me ), 1.32 (d, 3 J HH = 6.9Hz, 12H, CH Me 2), 1.25 (d, 3 J HH = 6.9 Hz, 12H, CH Me 2), 1.23 (d, 3 J HH = 6.9 Hz, 12H, CH Me 2), 1.12 (d, 3 J HH= 6.9 Hz, 12H, CH Me 2). 13 C{ 1 H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 147.0 (Ar- C ), 146.9 (Ar- C ), 142.2 (Ar- C ), 141.8 (Ar- C ), 132.7 (N C H), 126.6 (Ar- C ), 126.5 (Ar- C ),124.2 (Ar- C ), 123.8 (Ar- C ), 120.9 (N C Cl), 53.5 (N C H2 C H2N), 52.9 (N C H2 C H2N), 37.6 (N Me ), 34.4 (N Me ), 28.7 ( C HMe2), 28.5 (CH Me 2), 25.12 (CH Me 2), 25.10(CH Me 2), 24.2 (CH Me 2), 24.0 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 25.46 (br). HRMS(m / z): [M+H] + calcd. for C 56 H 84 N8B2Cl: 925.66881, found: 925.67230. Example 8: Reaction of 1,4-diazabuttriene compound 6 with MeOH

[0094] MeOH (1 mL) was added to a 1.0 mL THF solution of compound 6 (0.034 mmol), and the mixture was stirred at room temperature for 2 days. The solvent was then removed under reduced pressure to give compound 12 (0.032 mmol, white solid). Compound 12 was characterized as follows: 1 H NMR (600 MHz, C6D6, 298 K): δ(ppm) = 7.10 (br, 6H, Ar- H ), 6.99 (br,6H, Ar- H ), 5.57 (s, 1H NC H ), 3.59 (sept, 3 J HH = 6.9 Hz, 8H, C H Me2), 3.44 (s, 4H, NC) H 2C H 2N), 3.42 (s, 4H, NC H 2C H 2N), 2.71 (s, 3H, N Me ), 2.48 (s, 3H, N Me ),2.38 (s, 3H, O Me ), 1.28-1.31 (m, 24H, CH Me 2), 1.21 (d, 3 J HH = 6.9 Hz, 24H, CH Me 2). 13 C{ 1 H} NMR (151 MHz, C6D6, 298 K): δ(ppm) = 147.2 (Ar- C ), 147.1 (Ar- C ), 145.6 (N C OMe), 142.6 (Ar- C ), 142.2 (Ar- C ), 132.2 (N C H), 126.6 (Ar- C ),126.2 (Ar- C ), 124.3 (Ar- C ), 123.7 (Ar- C), 120.9 (N C Cl), 57.34 (O Me ), 53.6(N C H2 C H2N), 53.0 (N C H2 C H2N), 38.6 (N Me ), 33.8 (N Me ), 28.7 ( C HMe2), 28.5(CH Me 2), 25.11 (CH Me 2), 25.09 (CH Me 2), 24.2 (CH Me 2), 24.1 (CH Me 2). 11 B{ 1 H} NMR (193 MHz, C6D6, 298 K): δ(ppm) = 25.67 (br). HRMS(m / z): [M+H] + calcd. for C 57 H 87 N8B2O: 921.71835, found: 921.71887. Experimental Example 1: Stability Study Stability study of solid powders: The solid powders of compound 6 (prepared in Example 2) and compound 7 (prepared in Example 3) were placed at 25°C for 3 months, and the changes in content were detected. The results are shown in Table 1.

[0095] Solution stability study: Compound 6 and Compound 7 were dissolved in deuterated benzene to a concentration of 0.032 mol / L, respectively, and placed at 25℃ for 3 months. The changes in content were detected, and the results are shown in Table 1.

[0096] Content detection method: Trimethoxybenzene was used as an internal standard, and quantitative detection was performed by 1H NMR spectroscopy.

[0097] Table 1:

[0098] Note: The decrease in content after 3 months of storage at 25℃ = (1 - (content after 3 months of storage at 25℃ ÷ content after 0 days)) * 100%.

[0099] Conclusion: Compounds 6 and 7 provided by this invention exhibit excellent stability in both solid powder and solution states.

[0100] Application Example 1: Compounds 8, 9, 10, 11, and 12, prepared as sterically hindered α-diimine compounds, can be used as ligands in the Suzuki coupling reaction. For example, compounds 8, 9, 10, 11, and 12, respectively, were used as ligands in the following reactions:

[0101] Compound 13 (1.0 mmol), compound 14 (1.2 mmol), Na₂CO₃ (2.0 mmol), PdCl₂ (0.01 mmol), ligand (0.01 mmol, specific selections are shown in Table 2), and solvent (3 mL ethanol + 3 mL water) were mixed and reacted at 25 °C for 3 hours. After drying, compound 15 was obtained. The yields of compound 15 obtained using different ligands are shown in Table 2.

[0102] Table 2:

[0103] Conclusion: Compounds 8, 9, 10, 11, and 12 provided by this invention are α-diimine compounds with a sterically hindered framework structure. They can be used as ligands in the Suzuki coupling reaction, which is beneficial to improving the product yield of the Suzuki reaction and has excellent activity.

[0104] The method of this invention has been described through preferred embodiments. Those skilled in the art will readily be able to modify or appropriately alter and combine the methods and applications described herein within the scope, spirit, and context of this invention to implement and apply the technology of this invention. Those skilled in the art can refer to the content herein to appropriately improve process parameters. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included within the scope of this invention.

Claims

1. A method for synthesizing compound 3, characterized in that, include: ， Compound 1 and Compound 2 were reacted in solvent A. After the reaction was completed, solvent A was removed, and the mixture was extracted with benzene or toluene, filtered, and the filtrate was mixed with 12-crown ether-4 and stirred to obtain compound 3. Wherein, the Dipp group represents The TMS group represents trimethylsilyl, and the 12-C-4 in compound 3 represents 12-crown ether-4.

2. The method for synthesizing compound 3 according to claim 1, wherein in the first reaction, the molar ratio of compound 1 to compound 2 is 1:2 to 1:3, or 1:2; and / or Solvent A includes tetrahydrofuran; and / or For every 1 ml of solvent A, add 0.05 mmol to 0.5 mmol or 0.16 mmol of compound 1.

3. The method for synthesizing compound 3 according to any one of claims 1 to 2, wherein the molar ratio of 12-crown ether-4 to compound 1 is 1:1 to 1:1.5, or 1:

1.

4. The method for synthesizing compound 3 according to any one of claims 1 to 3, the method further comprising performing a first post-treatment after stirring, the first post-treatment comprising: Remove solvent, wash, and dry; Optionally, solvent removal in the first post-processing includes solvent removal under reduced pressure; Optionally, the washing in the first post-treatment includes washing with n-pentane or n-hexane.

5. A method for synthesizing compound Ia, characterized in that, include: ， Compound 3 reacts with an alkyl iodide in solvent B to give compound Ia; Among them, R 1 It is a C1~C10 straight-chain alkyl or a C3~C10 branched alkyl.

6. The method for synthesizing compound Ia according to claim 5, wherein R 1 Methyl or ethyl; and / or Solvent B includes at least one of benzene, toluene, diethyl ether, tetrahydrofuran, deuterated benzene, and deuterated toluene; and / or The molar ratio of compound 3 to the alkyl iodide is 1:1 to 1:3 or 1:1; and / or In the second reaction, 0.02 mmol to 0.06 mmol of compound 3 is added for every 1 ml of solvent B; and / or The second reaction takes 2 to 10 minutes, or 2 minutes; and / or The method for synthesizing compound Ia further includes synthesizing compound 3 according to the method for synthesizing compound 3 according to any one of claims 1 to 4.

7. A method for synthesizing compound IIa, characterized in that, include: ， Compound Ia is obtained by the synthetic method according to any one of claims 5 to 6, and then left to stand to spontaneously carry out a dimerization reaction to obtain compound IIa; Optionally, the method for synthesizing compound IIa further includes removing solvent B under reduced pressure after the dimerization reaction; Optionally, the settling time is 10 to 30 hours.

8. A compound, characterized in that, Compounds selected from the following structures: 、 、 、 、 、 、 、 、 、 ， Wherein, the Dipp group represents The TMS group represents a trimethylsilyl group; In compound Ia, R 1 Selected from C1-C10 straight-chain alkyl or C3-C10 branched alkyl, preferably methyl or ethyl; In compound IIa, R 1 Selected from C1-C10 straight-chain alkyl or C3-C10 branched alkyl, preferably methyl or ethyl; In compound 3, 12-C-4 represents 12-crown ether-4.

9. Use of compound IIa, compound 8, compound 9, compound 10, compound 11 or compound 12 of claim 8 as a ligand in the Suzuki reaction.

10. The use of compound 6 or compound 7 of claim 8 as a precursor in a reaction for preparing transition metal complex ligands; Optionally, the reaction for preparing transition metal complex ligands includes: Compound 6 or compound 7 is reacted with the first transition metal complex in a first solvent, filtered, the solvent in the filtrate is removed, washed, and dried to obtain the transition metal complex ligand. Optionally, the first transition metal complex comprises [(COD)IrCl]2 and / or [(CO)2RhCl]2; Optionally, the first solvent includes at least one of benzene, deuterated benzene, toluene, diethyl ether, and tetrahydrofuran; Optionally, the transition metal complex ligand includes compound 8 or compound 9.

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