Organic boron bifunctional catalyst based on cyclopropene ions as well as preparation method and application of organic boron bifunctional catalyst

Abstract

The invention belongs to the technical field of compound preparation, and particularly relates to an organoboron bifunctional catalyst based on cyclopropene ions as well as a preparation method and application of the organoboron bifunctional catalyst. The catalyst comprises two parts, namely cyclopropene ions and organoborane, in the structure of the catalyst, the cyclopropene ions are the smallest aromatic cations, and a three-membered ring of the cyclopropene ions contains two pi electrons, so that the cyclopropene ions conform to the Heffkel aromaticity rule. Wherein the triaminocyclopropene ions (TACs) have three amino substituent groups, so that the triaminocyclopropene ions (TACs) have excellent thermal stability and chemical stability. The catalyst disclosed by the invention is simple in synthesis method and adjustable in structure, and a new path is provided for design of an organic catalyst and application of the catalyst in ring-opening polymerization.

Description

Technical Field

[0001] The present invention belongs to the technical field of compound preparation, and particularly relates to an organoboron bifunctional catalyst based on cyclopropenium ion, and a preparation method and application thereof. Background Art

[0002] In the past two decades, the field of organocatalytic ring-opening polymerization has developed rapidly. Compared with transition metal catalytic systems, organocatalytic systems have unique advantages such as easy removal, modular design, and sustainability, which have promoted significant progress in this field, especially in the synthesis of biomedical and microelectronic materials. Since Hedrick's pioneering work on the ring-opening polymerization of lactide catalyzed by 4-dimethylaminopyridine (DMAP), a variety of organocatalysts have been developed, such as thiourea-based, amine-based, carbene-based, and phosphazene-based catalysts (Angew. Chem. Int. Ed. 2001, 40, 2712 - 2715; Green Chem. 2014, 16, 1687 - 1699; Macromolecules 2006, 39, 7863 - 7871.). These catalysts have shown high catalytic activity, stereoselectivity, and precise control over molecular weight and structure in the ROP reaction. In addition, organoboron compounds exhibit metal-like properties due to their electron-deficient boron atoms, and thus have great potential as metal-free catalysts. For example, when trialkylboranes combine with Lewis bases, stable Lewis adducts are formed, which can promote a series of ROP reactions, such as the polymerization of epoxides and their copolymerization with carbon dioxide, carbon disulfide, isocyanates, and acid anhydrides.

[0003] Although the binary catalytic system composed of triethylboron and other cocatalysts performs well in some polymerization reactions, its catalytic efficiency is usually low at low catalyst loadings, and it is necessary to increase the catalyst concentration to make up for this defect. This not only limits the preparation of high-molecular-weight polymers but also significantly increases the production cost (ACS Catal. 2022, 12, 11037 - 11070). To solve this problem, integrating the binary catalytic system into a single molecule through covalent bonds is an effective strategy. For example, connecting a quaternary ammonium salt and a borane through a covalent bond can exhibit excellent catalytic performance in the copolymerization of epoxides and carbon dioxide (J. Am. Chem. Soc. 2020, 142, 12245 - 12255). The catalytic activity of the above catalysts is still lower than that of advanced metal catalytic systems. To develop an organocatalyst comparable to metal catalytic systems, replacing the quaternary ammonium salt ion center with a cyclopropenium ion can achieve an improvement in catalytic activity and is expected to be a good alternative to metal catalytic systems. Summary of the Invention

[0004] To address the defects and deficiencies in the existing technologies, the primary objective of the present invention is to provide a class of organoboron bifunctional catalysts based on cyclopropenium ions. In the structure of this catalyst, cyclopropenium ions are the smallest aromatic cations. Due to the presence of two π electrons within their three-membered rings, they conform to the Hückel aromaticity rule. Among them, triaminocyclopropenium ions (TACs) exhibit excellent thermal and chemical stabilities due to having three amino substituents.

[0005] Another objective of the present invention is to provide a method for preparing the above-mentioned organoboron bifunctional catalyst based on cyclopropenium ions.

[0006] The present invention integrates borane and cyclopropenium ions into one molecule, and its catalytic activity is higher than that of its corresponding binary system; by introducing more boron centers into cyclopropenium ions, the synergistic effect of the multi-boron centers, counterions, and cyclopropenium ions endows such catalytic systems with higher catalytic activity, greatly enhancing the practicality of this class of catalysts.

[0007] Another objective of the present invention is to provide the application of the above-mentioned organoboron bifunctional catalyst based on cyclopropenium ions.

[0008] To achieve the above objectives, the present invention adopts the following technical solutions:

[0009] A class of cyclopropenium ion organoboron bifunctional catalysts provided by the present invention includes two parts: cyclopropenium ions and organoboranes, and can be mainly divided into six types of main structures, including the following structures:

[0010]

[0011] In structural formulas A - F: R1 is a hydrogen atom, or a substituted or unsubstituted C1 - C50 alkyl or aryl group; R2, R3, R4, and R5 are the same or different and are selected from C1 - C50 alkyl groups (preferably C3 - C15 alkyl groups) or aryl groups, where the substituents R2 and R3 form a covalent ring or do not form a covalent ring, and R4 and R5 form a covalent ring or do not form a covalent ring; X - is a counterion, is a borane;

[0012] wherein, n is an integer from 1 to 50.

[0013] Preferably, when R1 is a substituted C1 - C50 alkyl or aryl group, R1 contains one or more of the atoms N, O, P, Si, and S; the borane is one of non-cyclic boranes and cyclic boranes.

[0014] Preferably, the substituent R1 group is selected from the following structures:

[0015]

[0016] The groups formed by R2, R3, R4, and R5 after being connected to nitrogen are selected from the structures shown below:

[0017]

[0018] Among them, n and m are integers from 1 to 50.

[0019] Preferably, the counterion X - is one or a combination of two or more of fluoride ion, chloride ion, bromide ion, iodide ion, tetrafluoroborate ion, hexafluorophosphate ion, carboxylate ion, lithium tetrakis(pentafluorophenyl)borate anion, tetracarbonylnickel anion, carbonate ion, hypochlorite ion, phosphate ion, and phenoxide ion.

[0020] Preferably, the borane part in the chemical structural formula A-F is selected from the following structures:

[0021]

[0022] Preferably, the distance interval C1-C30 between the cyclopropenium ion or cyclopropene derivative and the borane in the chemical structural formula A-F (i.e., in formula A-F, n is preferably 1-30).

[0023] The preparation method of the above-mentioned cyclopropenium ion-based organoboron bifunctional catalyst includes the following steps:

[0024] Under an inert atmosphere, add the cyclopropenium ion with a terminal olefin and a hydroborating reagent into a reaction tube (the ratio of the olefin to the hydroborating reagent is 1:1 - 1:n, where n is greater than 1), add an organic solvent, react at a temperature range from room temperature to 100 °C for 1-72 h, remove the organic solvent after the reaction, and wash with n-hexane or n-pentane multiple times to obtain the cyclopropenium ion-based organoboron bifunctional catalyst described in any one of formula A-F;

[0025] The chemical formula of the cyclopropenium ion with a terminal olefin is:

[0026]

[0027] Among them, the definitions of n and substituents R1, R2, R3, R4, and R5 are the same as those in the chemical structural formula A-F; the counterion X - is one or a combination of two or more of fluoride ion, chloride ion, bromide ion, iodide ion, tetrafluoroborate ion, hexafluorophosphate ion, carboxylate ion, lithium tetrakis(pentafluorophenyl)borate anion, tetracarbonylnickel anion, carbonate ion, hypochlorite ion, phosphate ion, and phenoxide ion.

[0028] The substituent R1 group is selected from the structures shown below:

[0029]

[0030] The groups formed by R2, R3, R4, and R5 after bonding to nitrogen are selected from the following structures:

[0031]

[0032] Preferably, the borohydride reagent is selected from the following chemical structures:

[0033]

[0034] The present invention also applies the cyclopropenium ion-based organoboron bifunctional catalyst to the synthesis of organic small molecules or polymers, such as ring-opening copolymerization of epoxy or episulfide with anhydride, homopolymerization of epoxy with carbon dioxide or lactide, or homopolymerization of epoxy.

[0035] The raw materials required for the synthesis are prepared from one or two cyclic monomers by ring-opening under the action of a catalyst to obtain small molecule or polymer materials; the synthesis is carried out by reacting cyclic monomers with carbon dioxide, carbon monoxide, carbon disulfide, isocyanate under the action of a catalyst to prepare small molecule or polymer materials.

[0036] The cyclic monomers include but are not limited to the following structures:

[0037]

[0038]

[0039] Among them, n is an integer from 1 to 10.

[0040] The initiator structure required for the cyclopropenium ion-based organoboron bifunctional catalyst to catalyze the preparation of small molecule or polymer materials from cyclic monomers is as follows:

[0041]

[0042] The chain transfer agent or initiator required for the cyclopropenium ion-based organoboron bifunctional catalyst to catalyze the preparation of small molecule or polymer materials from cyclic monomers can be arbitrarily selected from one or more small molecule or macromolecular polymers containing active hydrogens such as amino group, mercapto group, hydroxyl group, phenolic hydroxyl group, carboxyl group, etc.

[0043] The cyclopropenium ion-based organoboron bifunctional catalyst of the present invention can also be supported on inorganic or organic substances for the preparation of organic small molecules or polymers.

[0044] Advantages of the present invention:

[0045] Compared with the prior art, the present invention integrates cyclopropenium ions and boranes into a molecule through covalent connection. The prepared cyclopropenium ion-based organoboron bifunctional catalyst has excellent performance in the ring-opening copolymerization of epoxides or episulfides with acid anhydrides, the copolymerization of epoxides with carbon dioxide, the homopolymerization of lactide, and the homopolymerization of epoxides, and exhibits excellent thermal stability and chemical stability. This method is expected to promote the development of high-performance organic catalysts and has broad application prospects, and can even be extended to more polymerization reactions. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 1H NMR spectrum of catalyst A1 prepared in Example 1 of the present invention.

[0047] Figure 2 13C NMR spectrum of catalyst A2 prepared in Example 2 of the present invention.

[0048] Figure 3 1H NMR spectrum of catalyst A3 prepared in Example 3 of the present invention.

[0049] Figure 4 1H NMR spectrum of catalyst A4 prepared in Example 4 of the present invention.

[0050] Figure 5 1H NMR spectrum of catalyst A5 prepared in Example 5 of the present invention.

[0051] Figure 6 1H NMR spectrum of catalyst A11 prepared in Example 11 of the present invention.

[0052] Figure 7 1H NMR spectrum of catalyst B1 prepared in Example 21 of the present invention.

[0053] Figure 8 1H NMR spectrum of catalyst C1 prepared in Example 23 of the present invention.

[0054] Figure 9 1H NMR spectrum of catalyst F1 prepared in Example 29 of the present invention.

[0055] Figure 10 X-ray single crystal diffraction pattern of catalyst A3 prepared in Example 3 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0056] The following examples are used to illustrate the present invention, but do not limit the protection scope of the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. The test methods in the following examples are all conventional methods unless otherwise specified.

[0057] The general preparation process of the precursors required for the examples is as follows:

[0058] The preparation process of the catalyst precursors shown in Formula A and Formula B is as follows:

[0059] First, the general synthesis process of TAC is as follows: Add pentachlorocyclopropane (35 mmol) to a flask and dissolve it in 250 mL of chloroform. At 0 °C, slowly add secondary amine (280 mmol) and react for 2 h - 48 h. After the reaction, wash with 1 M hydrochloric acid, then extract with deionized water. The organic phase is concentrated in vacuo and separated by column chromatography to obtain white solid TAC.

[0060] Add TAC (1.0 mmol, 1.0 equiv) to the reaction flask, then add terminal olefin amine (1.0 mmol, 1.0 equiv) and triethylamine (2.0 mmol, 2.0 equiv). Dissolve in dichloromethane and stir for 48 h. Purify by column chromatography to obtain the precursor.

[0061] The general structural formula of TAC involved is The type of the prepared precursor is

[0062]

[0063] The preparation process of the precursors of the catalysts shown in Formula C and Formula F is as follows:

[0064] Add pentachlorocyclopropane (1.0 mol, 1.0 equiv) to the reaction flask, add secondary amine with terminal olefin (7.0 mol, 7.0 equiv), react for 48 h, and separate by column chromatography to obtain the precursor.

[0065] The type of the prepared precursor is

[0066] The preparation process of the precursors of the catalysts shown in Formula D and Formula E is as follows:

[0067] Add f (4.0 mmol, 1.0 equiv) to the reaction flask, add sodium hydroxide (120 mmol, 300 equiv), 50 mL of methanol each, reflux for 4 h, and separate by column chromatography to obtain the product, f'.

[0068] The structure of the product f' is

[0069] Add f' (1.0 mmol, 1.0 equiv) to the reaction flask, then add oxalyl chloride (2.0 mmol, 2.0 equiv) and react for 2 h to obtain the product f".

[0070] The structure of f" is

[0071] Precursor d and e are obtained by the synthesis method of precursor a and b in accordance with f.

[0072] The structure of precursor d is The structure of precursor e is

[0073] During the preparation process of the above precursors, the definitions of n, counterion X - , and substituents R1, R2, R3, R4, R5 are the same as those in chemical structural formulas A - F.

[0074] Preparation of catalyst A1 in Example 1

[0075] The reaction path is as follows:

[0076]

[0077] In the glove box, a1 (0.5 mmol, 1.0 equiv) and 9 - borabicyclo[3.3.1]nonane (9 - BBN) (0.65 mmol, 1.3 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n - hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A1 (quantitative yield).

[0078] 1H NMR characterization of A1 is as follows: 1 1H NMR (500 MHz, CDCl3) δ 7.48 - 7.36 (m, 2H), 7.32 - 7.14 (m, 3H), 3.85 - 3.73 (m, 2H), 3.73 - 3.64 (m, 4H), 1.91 - 1.52 (m, 14H), 1.45 - 1.36 (m, 2H), 1.23 (d, J = 6.9, 2.2 Hz, 24H), 1.9 - 1.17 (m, 2H).

[0079] Preparation of catalyst A2 in Example 2

[0080] The reaction path is as follows:

[0081]

[0082] In the glove box, a2 (0.5 mmol, 1.0 equiv) and 9 - BBN (0.65 mmol, 1.3 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1After monitoring the completion of the reaction by \(^1H\) NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n - hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A2 (quantitative yield).

[0083] The \(^1H\) NMR characterization of A2 is as follows: 1 \(^1H\) NMR (500 MHz, \(CDCl_3\)) δ 7.45 (t, \(J\) = 7.5 Hz, 2H), 7.32 - 7.23 (m, 3H), 3.87 (t, \(J\) = 7.7 Hz, 2H), 3.75 - 3.70 (m, 4H), 1.89 - 1.76 (m, 14H), 1.54 - 1.49 (m, 21H), 1.37 - 1.31 (m, 4H), 1.25 (d, \(J\) = 6.4 Hz, 24H), 1.19 - 1.12 (m, 2H).

[0084] Example 3 Preparation of catalyst A3

[0085] The reaction route is as follows:

[0086]

[0087] In the glove box, a3 (0.5 mmol, 1.0 equiv) and 9 - BBN (0.65 mmol, 1.3 equiv) were successively added to a 25 - mL reaction tube, 1.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by \(^1H\) NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n - hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A3 (quantitative yield).

[0088] The \(^1H\) NMR characterization of A3 is as follows: 1 \(^1H\) NMR (500 MHz, \(CDCl_3\)) δ 7.48 - 7.42 (m, 2H), 7.32 - 7.27 (m, 1H), 7.26 - 7.22 (m, 2H), 3.85 - 3.78 (m, 2H), 3.73 - 3.64 (m, 4H), 1.86 - 1.72 (m, 7H), 1.68 - 1.53 (m, 7H), 1.52 - 1.42 (m, 2H), 1.35 - 1.28 (m, 4H), 1.23 (d, \(J\) = 6.9 Hz, 24H), 1.17 - 1.13 (m, 2H).

[0089] Example 4 Preparation of catalyst A4

[0090] The reaction route is as follows:

[0091]

[0092] In the glove box, a4 (0.5 mmol, 1.0 equiv) and 9-BBN (0.65 mmol, 1.3 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to completion, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A4 (quantitative yield).

[0093] The 1H NMR characterization of A4 is as follows: 1 1H NMR (500 MHz, CDCl3) δ 7.43 (t, J = 7.7 Hz, 2H), 7.27 (t, J = 7.4 Hz, 1H), 7.25 - 7.19 (m, 2H), 3.83 - 3.75 (m, 2H), 3.71 - 3.63 (m, 4H), 1.86 - 1.72 (m, 10H), 1.65 - 1.52 (m, 4H), 1.44 - 1.37 (m, 2H), 1.36 - 1.23 (m, 6H), 1.21 (d, J = 6.9 Hz, 24H), 1.14 - 1.12 (m, 2H).

[0094] Example 5 Preparation of Catalyst A5

[0095] The reaction pathway is as follows:

[0096]

[0097] In the glove box, a5 (0.5 mmol, 1.0 equiv) and 9-BBN (0.5 mmol, 1.0 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to completion, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A5 (quantitative yield).

[0098] The 1H NMR characterization of A5 is as follows: 1 1H NMR (500 MHz, CDCl3) δ 3.96 - 3.81 (m, 4H), 3.54 - 3.46 (m, 2H), 3.32 (s, 3H), 1.91 - 1.62 (m, 14H), 1.54 - 1.47 (m, 2H), 1.39 (d, J = 6.9 Hz, 24H), 1.21 - 1.14 (m, 2H).

[0099] Preparation of Catalyst A6 in Example 6

[0100] The reaction pathway is as follows:

[0101]

[0102] In the glove box, a6 (0.5 mmol, 1.0 equiv) and 9-BBN (0.5 mmol, 1.0 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of tetrahydrofuran was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored to completion by 1 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A6 (quantitative yield).

[0103] Preparation of Catalyst A7 in Example 7

[0104] The reaction pathway is as follows:

[0105]

[0106] In the glove box, a7 (0.5 mmol, 1.0 equiv) and 9-BBN (0.65 mmol, 1.3 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of ethyl acetate was added, and then the reaction was carried out at 45 °C for 12 h. After the reaction was monitored to completion by 1 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A7 (quantitative yield).

[0107] Preparation of Catalyst A8 in Example 8

[0108] The reaction pathway is as follows:

[0109]

[0110] In the glove box, a7 (0.5 mmol, 1.0 equiv) and 9-BBN (0.5 mmol, 1.0 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of ethyl acetate was added, and then the reaction was carried out at 45 °C for 12 h. After the reaction was monitored to completion by 1 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A8 (quantitative yield).

[0111] Preparation of Catalyst A9 in Example 9

[0112] The reaction pathway is as follows:

[0113]

[0114] In the glove box, a9 (1.0 mmol, 1.0 equiv) and 9-BBN (1.01 mmol, 1.01 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of dichloromethane was added, and then the reaction was carried out at 45 °C for 12 h. After the reaction was monitored by 1 1H NMR to be complete, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A9 (quantitative yield).

[0115] Preparation of Catalyst A10 in Example 10

[0116] The reaction pathway is as follows:

[0117]

[0118] In the glove box, a10 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of dichloromethane was added, and then the reaction was carried out at 45 °C for 12 h. After the reaction was monitored by 1 1H NMR to be complete, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A10 (quantitative yield).

[0119] Preparation of Catalyst A11 in Example 11

[0120] The reaction pathway is as follows:

[0121]

[0122] In the glove box, a11 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to be complete, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A11 (quantitative yield).

[0123] 1H NMR characterization of A11 is as follows:1 1H NMR (500 MHz, CDCl3) δ 9.61 (t, J = 6.1 Hz, 1H), 3.92 - 3.77 (m, 4H), 3.51 - 3.41 (m, 2H), 1.99 - 1.58 (m, 16H), 1.36 (d, J = 6.9 Hz, 24H), 1.24 - 1.12 (m, 2H).

[0124] Example 12 Preparation of Catalyst A12

[0125] The reaction pathway is as follows:

[0126]

[0127] In a glove box, a12 (1.0 mmol, 1.0 equiv) and 9 - BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n - hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A12 (quantitative yield).

[0128] Example 13 Preparation of Catalyst A13

[0129] The reaction pathway is as follows:

[0130]

[0131] In a glove box, a13 (1.0 mmol, 1.0 equiv) and 9 - BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 1.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n - hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A13 (quantitative yield).

[0132] Example 14 Preparation of Catalyst A14

[0133] The reaction pathway is as follows:

[0134]

[0135] In the glove box, a14 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 2.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 the reaction was monitored by 1H NMR and completed, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A14 (quantitative yield).

[0136] Example 15 Preparation of Catalyst A15

[0137] The reaction pathway is as follows:

[0138]

[0139] In the glove box, a15 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 2.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 the reaction was monitored by 1H NMR and completed, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A15 (quantitative yield).

[0140] Example 16 Preparation of Catalyst A16

[0141] The reaction pathway is as follows:

[0142]

[0143] In the glove box, a16 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 2.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 the reaction was monitored by 1H NMR and completed, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A16 (quantitative yield).

[0144] Example 17 Preparation of Catalyst A17

[0145] The reaction pathway is as follows:

[0146]

[0147] In the glove box, a17 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 2.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A17 (quantitative yield).

[0148] Example 18 Preparation of Catalyst A18

[0149] The reaction pathway is as follows:

[0150]

[0151] In the glove box, a18 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 2.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A18 (quantitative yield).

[0152] Example 19 Preparation of Catalyst A19

[0153] The reaction pathway is as follows:

[0154]

[0155] In the glove box, a19 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 2.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by 1H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A19 (quantitative yield).

[0156] Example 20 Preparation of Catalyst A20

[0157] The reaction pathway is as follows:

[0158]

[0159] In the glove box, a20 (1.0 mmol, 1.0 equiv) and 9-BBN (1.2 mmol, 1.2 equiv) were successively added to a 25 mL reaction tube, 2.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to be complete, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder A20 (quantitative yield).

[0160] Example 21 Preparation of Catalyst B1

[0161] The reaction pathway is as follows:

[0162]

[0163] In the glove box, b1 (1.0 mmol, 1.0 equiv) and 9-BBN (2.2 mmol, 2.2 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to be complete, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder B1 (quantitative yield).

[0164] 1H NMR characterization of B1 is as follows: 1 1H NMR (500 MHz, CDCl3) δ 3.86 - 3.77 (m, 4H), 1.89 - 1.73 (m, 4H), 1.85 - 1.73 (m, 16H), 1.72 - 1.62 (m, 8H), 1.49 - 1.43 (m, 4H), 1.33 (d, J = 7.0 Hz, 24H), 1.25 - 1.17 (m, 4H), 1.16 - 1.10 (m, 4H).

[0165] Example 22 Preparation of Catalyst B2

[0166] The reaction pathway is as follows:

[0167]

[0168] In the glove box, b2 (1.0 mmol, 1.0 equiv) and 9-BBN (2.2 mmol, 2.2 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1After monitoring the completion of the reaction by \(^1\)H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder B2 (quantitative yield).

[0169] Example 23 Preparation of Catalyst C1

[0170] The reaction pathway is as follows:

[0171]

[0172] In a glove box, c1 (1.0 mmol, 1.0 equiv) and 9-BBN (3.3 mmol, 3.3 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by \(^1\)H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder C1 (quantitative yield).

[0173] The \(^1\)H NMR characterization of C1 is as follows: 1 \(^1\)H NMR (500 MHz, CDCl\(_3\)) δ 3.41 - 3.31 (m, 6H), 3.20 (s, 9H), 1.91 - 1.77 (m, 24H), 1.72 - 1.57 (m, 18H), 1.31 - 1.25 (m, 6H), 1.24 - 1.16 (m, 6H).

[0174] Example 24 Preparation of Catalyst C2

[0175] The reaction pathway is as follows:

[0176]

[0177] In a glove box, c2 (1.0 mmol, 1.0 equiv) and 9-BBN (3.3 mmol, 3.3 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by \(^1\)H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder C2 (quantitative yield).

[0178] Example 25 Preparation of Catalyst D1

[0179] The reaction pathway is as follows:

[0180]

[0181] In the glove box, d1 (1.0 mmol, 1.0 equiv) and 9-BBN (4.4 mmol, 4.4 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to completion, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder D1 (quantitative yield).

[0182] Example 26 Preparation of Catalyst D2

[0183] The reaction pathway is as follows:

[0184]

[0185] In the glove box, d2 (1.0 mmol, 1.0 equiv) and 9-BBN (4.4 mmol, 4.4 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to completion, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder D2 (quantitative yield).

[0186] Example 27 Preparation of Catalyst D3

[0187] The reaction pathway is as follows:

[0188]

[0189] In the glove box, d3 (1.0 mmol, 1.0 equiv) and 9-BBN (4.4 mmol, 4.4 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After the reaction was monitored by 1 1H NMR to completion, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder D3 (quantitative yield).

[0190] Example 28 Preparation of Catalyst E1

[0191] The reaction pathway is as follows:

[0192]

[0193] In the glove box, e1 (1.0 mmol, 1.0 equiv) and 9-BBN (5.5 mmol, 5.5 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by \(^1\)H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder E1 (quantitative yield).

[0194] Example 29 Preparation of Catalyst F1

[0195] The reaction pathway is as follows:

[0196]

[0197] In the glove box, f1 (1.0 mmol, 1.0 equiv) and 9-BBN (6.6 mmol, 6.6 equiv) were successively added to a 25 mL reaction tube, 3.0 mL of anhydrous chloroform was added, and then the reaction was carried out at 60 °C for 12 h. After 1 monitoring the completion of the reaction by \(^1\)H NMR, the reaction mixture was concentrated under vacuum to obtain a crude product, which was then further purified by washing three times with n-hexane to obtain a white solid. Finally, the white solid was dried under vacuum at 40 °C for 8 h to obtain white powder F1 (quantitative yield).

[0198] The \(^1\)H NMR characterization of F1 is as follows: 1 \(^1\)H NMR (500 MHz, CDCl\(_3\)) δ 3.38 - 3.32 (m, 12H), 1.92 - 1.72 (m, 60H), 1.70 - 1.65 (m, 24H), 1.60 - 1.58 (m, 10H), 1.25 - 1.17 (m, 14H).

[0199] A series of cyclopropenium ion-based organoboron bifunctional catalysts were obtained from the above examples. To verify their catalytic activities, they were applied in the ring-opening copolymerization of epoxides and acid anhydrides, the ring-opening copolymerization of epoxides and carbon dioxide, the ring-opening polymerization of lactide and epoxides to evaluate the catalyst activities.

[0200] The cyclopropenium ion-based organoboron catalyst was applied to the ring-opening copolymerization of epoxides and acid anhydrides. The monomer structures of the epoxides and acid anhydrides used in the following application examples are:

[0201]

[0202] Application Examples 1 - 18: Ring-opening copolymerization of epoxides and acid anhydrides catalyzed by Catalyst A3

[0203]

[0204] The operation process is as follows:

[0205] In the glove box, catalyst A3, anhydride and epoxy were successively added into the reaction tube, which was completely sealed and placed in a preheated oil bath. Polymerization was completed at 45 - 110 °C. The reaction solution was taken to measure nuclear magnetic resonance (NMR) to characterize the conversion of monomers and the selectivity of the product, and the polymerization molecular weight and molecular weight distribution were verified by gel permeation chromatography (GPC). The test results are shown in Table 1.

[0206] Table 1. Polymerization results of Application Examples 1 - 18

[0207]

[0208] Among them, the conversion rate (%) of a represents the conversion rate of anhydride, and the selectivity (%) represents the content of ester bonds in the formed polymer, both of which are calculated by proton nuclear magnetic resonance spectrum; M n and PDI in b are measured by GPC.

[0209] The cyclopropenium ion organoboron catalyst is applied to the ring-opening copolymerization reaction of epoxy and carbon dioxide. The structure of the catalyst applied is as follows:

[0210]

[0211] Application Examples 19 - 21: Use catalysts A6, B1, and C1 to catalyze the ring-opening copolymerization of epoxy and carbon dioxide.

[0212]

[0213] The operation process is as follows:

[0214] In the glove box, the catalyst and CHO were successively added into the high-pressure reaction kettle, which was completely sealed, charged with 15 bar of carbon dioxide, and polymerization was completed at 80 °C. The reaction solution was taken to measure NMR to characterize the conversion of monomers and the selectivity of the product. The polymerization results are shown in Table 2.

[0215] Table 2. Polymerization results of Application Examples 19 - 21

[0216]

[0217] Among them, both the conversion rate (%) of a and the selectivity (%) are calculated by proton nuclear magnetic resonance spectrum.

[0218] The cyclopropenium ion organoboron catalyst is applied to the ring-opening polymerization reaction of epoxy. The structure of the catalyst applied is as follows:

[0219]

[0220] Application Examples 21 - 23: Catalyze the ring - opening polymerization of epoxides using catalysts B1, C1, and F1.

[0221]

[0222] The operation process is as follows:

[0223] Under an inert atmosphere at 0 °C, the catalyst and PO are successively added to the reaction tube, which is completely sealed. After the polymerization ends, the reaction solution is taken to measure NMR to characterize the monomer conversion rate and the selectivity of the product; the polymerization molecular weight and molecular weight distribution are verified by GPC. The test results are shown in Table 3.

[0224] Table 3. Polymerization results of Application Examples 22 - 24

[0225]

[0226] Among them, both the a conversion rate (%) and selectivity (%) are calculated by 1H NMR; b M n and PDI are measured by GPC

[0227] The cyclic propylene ion organoboron catalyst is applied to the ring - opening polymerization reaction of epoxides. The representative catalyst structures applied are as follows:

[0228]

[0229] Application Example 25: Catalyze the ring - opening polymerization of lactide using A11.

[0230]

[0231] The operation process is as follows:

[0232] In the glove box, the catalyst, LLA, and CHO are successively added to the reaction tube, dichloromethane is added as a solvent, and it is completely sealed and reacted at 45 °C. After the polymerization ends, the reaction solution is taken to measure NMR to characterize the monomer conversion rate and the selectivity of the product; the polymerization molecular weight and molecular weight distribution are verified by GPC. The test results are shown in Table 3.

[0233]

[0234] Among them, both the a conversion rate (%) and selectivity (%) are calculated by 1H NMR; b M n and PDI are measured by GPC.

[0235] Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention. The present invention may also have various other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and deformations according to the present invention, but these corresponding changes and deformations shall all fall within the protection scope of the appended claims of the present invention.

Claims

1. An organic boron bifunctional catalyst based on a cyclopropenyl ion, characterized in that The chemical structural formula of the catalyst is as follows: In structural formulas A - F: R1 is a hydrogen atom, or a substituted or unsubstituted C1 - C50 alkyl or aryl group; R2, R3, R4, and R5 are the same or different and are selected from alkyl or aryl groups, where the substituents R2 and R3 may or may not form a covalent ring, and R4 and R5 may or may not form a covalent ring; X - is a counterion, is a borane; Among them, n is an integer from 1 to 50.

2. The organoboron bifunctional catalyst based on cyclopropenium ion according to claim 1, characterized in that, When the said R1 is a substituted C1-C50 alkyl or aryl group, R1 contains one or more of N, O, P, Si, S atoms; the said borane is one of non-cyclic borane and cyclic borane; R2, R3, R4, R5 are the same or different and are selected from C1-C50 alkyl or aryl groups.

3. The organic boron bifunctional catalyst based on cyclopropenyl ion according to claim 1 or 2, characterized in that, The said substituent R1 is selected from the following structures: The groups formed by connecting the said substituents R2, R3, R4, R5 to nitrogen are selected from the following structures: Among them, n and m are integers from 1 to 50.

4. The organic boron bifunctional catalyst based on cyclopropenyl ion according to claim 1 or 2, characterized in that, The counterion X - is one or a combination of two or more of fluoride ion, chloride ion, bromide ion, iodide ion, tetrafluoroborate ion, hexafluorophosphate ion, carboxylate ion, lithium tetrakis(pentafluorophenyl)borate anion, tetracarbonylnickel anion, carbonate ion, hypochlorite ion, phosphate ion, and phenoxide ion.

5. The organic boron bifunctional catalyst based on cyclopropenium ions according to claim 1 or 2, characterized in that, The borane part in the chemical structural formulas A-F is selected from the following structures:

6. The organic boron bifunctional catalyst based on cyclopropenyl ion according to claim 1 or 2, characterized in that, The distance interval between the cyclopropenium ion or cyclopropene derivative and the borane in the said chemical structural formulas A-F is C1-C30.

7. The preparation method of the organic boron bifunctional catalyst based on cyclopropenyl ion according to any one of claims 1-6, characterized in that, It includes the following steps: Under an inert atmosphere, mix the cyclopropenium ion with a terminal olefin and a hydroboration reagent, add an organic solvent, react at room temperature to 100 °C for 1-72 h, and after the reaction is completed, remove the organic solvent with n-hexane or n-pentane multiple times to obtain the cyclopropenium ion-based organoboron bifunctional catalyst described in any one of formulas A-F.

8. The preparation method according to claim 7, characterized in that, The cyclopropenium ion with a terminal olefin is selected from compounds with the following structures: wherein the definitions of n and substituents R1, R2, R3, R4, and R5 are the same as those in claim 1; the counterion X - is one or a combination of two or more of fluoride ion, chloride ion, bromide ion, iodide ion, tetrafluoroborate ion, hexafluorophosphate ion, carboxylate ion, lithium tetrakis(pentafluorophenyl)borate anion, tetracarbonylnickel anion, carbonate ion, hypochlorite ion, phosphate ion, and phenoxide ion.

9. The preparation method according to claim 7, characterized in that, The hydroboration reagent is selected from compounds with the following structures:

10. Use of the organic boron bifunctional catalyst based on cyclopropenyl ion according to any one of claims 1-6, characterized in that, The cyclopropenium ion-based organoboron bifunctional catalyst is applied to the synthesis of organic small molecules or polymers.

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