A composite catalyst for the preparation of β-lactone by epoxide ring-expansion carbonylation, its preparation method and application

Abstract

This invention discloses a composite catalyst for the preparation of β-lactones via ring-expansion carbonylation of epoxides, its preparation method, and its applications. The composite catalyst of this invention consists of two parts: a quaternized or quaternized porous organic cage promoter and a metal complex-carbonyl catalyst of an organic nitrogen-containing polymer. The metal complex-carbonyl catalyst of the organic nitrogen-containing polymer consists of a metal complex of the organic nitrogen-containing polymer and a metal carbonyl compound. The metal complex of the organic nitrogen-containing polymer consists of an organic nitrogen-containing polymer support and a coordinated metal species. The cationic P in the promoter... + Or N + This catalyst exhibits a significant promoting effect on carbonylation reactions, accelerating the ring-opening of epoxides. Furthermore, the porosity of the organic cage facilitates mass transfer and diffusion during the carbonylation process, enhancing its carbonylation activity. This catalyst demonstrates excellent performance in the catalytic synthesis of β-lactones from epoxides, laying the foundation for the industrial application of epoxide carbonylation reactions.

Description

Technical Field

[0001] This invention belongs to the field of epoxide carbonylation reaction technology, specifically relating to a composite catalyst for the preparation of β-lactone by epoxide ring expansion carbonylation, its preparation method, and its application. Background Technology

[0002] β-lactones are β-lactone compounds and important chemical intermediates. On the one hand, their high ring-opening reactivity allows for the synthesis of various bifunctional compounds; on the other hand, a more important application of β-lactones is in the synthesis of biodegradable plastics, polyhydroxyalkanoates (PHAs), which hold promise for replacing traditional plastics and addressing the increasingly serious environmental pollution problem. However, the preparation of β-lactones is challenging, significantly limiting their application in the chemical industry.

[0003] The synthesis of β-lactones via carbonylation using inexpensive CO and epoxides is an ideal route. Most reported catalysts are homogeneous, with the most classic being the classic homogeneous bimetallic [Lewis acid] developed by Coates. + [Co(CO)4] - Lewis acids are catalysts that form mononuclear metal complexes with metals at the metal center, using porphyrin (TPP) derivatives, salen derivatives, and phthalocyanine derivatives as ligands. These complexes utilize N and O atoms to form the metal. This system exhibits significant advantages such as selectivity and high activity. Homogeneous Lewis acid. + [Co(CO)4] - The catalytic carbonylation of epoxides primarily occurs via [Lewis acid]. + Activation of epoxides, [Co(CO)4] - The process involves four steps: ring opening, CO insertion, and ring closing. However, homogeneous processes consistently face the challenge of catalyst separation, a problem that is expected to be solved by homogeneous heterogeneous processes. Currently, there are few reported heterogeneous carbonylation systems, and their activity is relatively low (generally only 10-20 h). -1 The selectivity is also poor (Inorg. Chem. 2020, 59, 2881-2889). This is mainly due to several reasons: (1) Heterogeneous catalysts are limited by diffusion and mass transfer, which greatly reduces the catalytic rate; (2) The composition of heterogeneous catalysts is more complex than that of homogeneous catalysts, and they do not have a specific single structure like homogeneous catalysts. In order to solve the above problems, the work in two aspects is of great significance: (1) to learn from the characteristics of homogeneous systems in heterogeneous systems to improve carbonylation activity; (2) the mechanism of heterogeneous systems may be different from that of homogeneous systems. The introduction of promoters in heterogeneous systems is rarely reported, and it is hoped that promoters can accelerate the carbonylation rate.

[0004] Porous organic cages are a new type of porous organic material developed after metal-organic frameworks (MOFs) and covalent organic frameworks (COFs). Unlike the three-dimensional, infinitely extended network structure of MOFs and COFs, porous organic cages are discrete molecular crystal materials. Discrete molecular units are stacked into an ordered porous structure through weak interactions, and their pores can be composed of internal cavities and interconnected channels formed by stacking. Porous organic cages often possess characteristics such as high specific surface area, extensive hierarchical channels, tunable pore microenvironments, and solubility. Generally, porous organic cages containing phosphorus and nitrogen exhibit good solubility and are soluble in a variety of solvents. The solubility of porous organic cages holds promise for achieving high activity similar to homogeneous catalysis in reactions. However, porous cages with typical cationic frameworks are generally insoluble in most solvents, which greatly hinders their application in near-homogeneous systems. Therefore, developing novel soluble or highly dispersible quaternary phosphonium or quaternary ammonium salts of porous organic cages has become a key issue. Summary of the Invention

[0005] To address the technical problems described in the background section, this invention provides a composite catalyst for the preparation of β-lactones via ring-expansion carbonylation of epoxides, its preparation method, and its applications. The composite catalyst of this invention consists of two parts: a cationic porous organic cage promoter and a metal complex-carbonyl catalyst of an organic nitrogen-containing polymer. The promoter is a quaternized or quaternized porous organic cage. The metal complex-carbonyl catalyst of the organic nitrogen-containing polymer consists of a metal complex of the organic nitrogen-containing polymer and a metal carbonyl compound. The metal complex of the organic nitrogen-containing polymer is composed of an organic nitrogen-containing polymer support and a coordinated metal species. The cationic P in the promoter... + Or N + This catalyst exhibits a significant promoting effect on carbonylation reactions, effectively accelerating the ring-opening of epoxides. Furthermore, the porosity and solubility of the quaternized or quaternized porous organic cages facilitate mass transfer and diffusion during the carbonylation process, enhancing its activity. In addition, the quaternized or quaternized porous organic cages can precipitate in methanol, simplifying the separation between the cages and the product, allowing them to switch between soluble and insoluble states during the reaction. Under specific temperature and pressure conditions, this type of catalyst demonstrates excellent performance in catalyzing the conversion of epoxides to β-lactones, laying the foundation for the industrial application of epoxide carbonylation reactions.

[0006] The technical solution of the present invention is as follows:

[0007] This invention provides a composite catalyst for the preparation of β-lactones by ring-expansion carbonylation of epoxides. The composite catalyst consists of two parts: a quaternized or quaternized porous organic cage promoter and a metal complex-carbonyl catalyst of an organic nitrogen-containing polymer. The promoter is prepared by reacting a porous organic cage with a quaternizing or quaternizing agent. The porous organic cage is prepared by reacting an aldehyde-containing nitrogen- or phosphine-containing monomer with 1,2-cyclohexanediamine. The metal complex-carbonyl catalyst of the organic nitrogen-containing polymer consists of a metal complex (Lewis Acid moiety) of the organic nitrogen-containing polymer and a metal carbonyl compound. The metal complex of the organic nitrogen-containing polymer consists of an organic nitrogen-containing polymer support and a coordinated metal species. The organic nitrogen-containing polymer support is prepared by free radical polymerization of a vinyl-containing nitrogen-containing monomer. The coordinated metal of the organic nitrogen-containing polymer support is one of Cr, Al, or Ti. The precursor of the metal carbonyl compound is M. 1 x [M 2 (CO) w ], where M 1 M is an alkali metal. 2 The catalyst is composed of Co, x is 1, and w is 4; the coordinated metal accounts for 0.01 to 5.0 wt% of the total mass of the catalyst, preferably 0.2 to 3.0 wt% of the total mass of the catalyst; Co accounts for 0.01 to 5.0 wt% of the total mass of the catalyst, preferably 0.2 to 3.0 wt% of the total mass of the catalyst.

[0008] Based on the above technical solution, further, M 1 It can be Na or K.

[0009] Based on the above technical solution, the nitrogen-containing or phosphine-containing monomer containing an aldehyde group is one of the following compounds AH; the quaternizing agent or quaternizing agent is one of the compounds IN;

[0010]

[0011] Based on the above technical solution, the vinyl-containing nitrogen-containing monomer is one of the compounds OT; the coordinated metal precursor is one of TiCl4, Cr(OAc)3, Cr2(C2O4)3·6H2O, CrCl3·3THF, Al(OAc)3, Al2(C2O4)3, and AlCl3.

[0012]

[0013] In another aspect of the present invention, the method for preparing the above-mentioned composite catalyst is wherein the composite catalyst is obtained by uniformly mixing two parts: a quaternized or quaternized porous organic cage promoter and a metal complex-carbonyl catalyst of an organic nitrogen-containing polymer. The molar ratio of the quaternized or quaternized porous organic cage promoter and the metal complex-carbonyl catalyst of the organic nitrogen-containing polymer is 10:1 to 1:10.

[0014] Based on the above technical solution, the preparation method of the additive further includes the following steps: under an inert atmosphere, a porous organic cage material and one of the quaternizing or quaternizing reagents N1 are added to a solvent, stirred at -80 to 100°C for 5 to 72 hours, concentrated by rotary evaporation, filtered and dried to obtain a quaternized or quaternized porous organic cage; wherein the molar ratio of P or N to the quaternizing or quaternizing reagent in the porous organic cage is 1:1 to 1:20.

[0015] Based on the above technical solution, the solvent is further selected from one or more of ethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, and 1,4-dioxane.

[0016] Based on the above technical solution, the preparation method of the porous organic cage material further includes the following steps: under an inert atmosphere, one of the nitrogen-containing or phosphine-containing monomers AH containing aldehyde groups and 1,2-cyclohexanediamine are added to a solvent, reacted at 0-100℃ for 24-120h, the insoluble substances are removed by filtration, the filtrate is concentrated, methanol is added to precipitate the solid, and the porous organic cage material is obtained after filtration and washing, wherein the molar ratio of the nitrogen-containing or phosphine-containing monomer containing aldehyde groups to 1,2-cyclohexanediamine is 1:1 to 1:5.

[0017] Based on the above technical solution, the solvent is further selected from one or more of ethyl acetate, n-hexane, cyclohexane, toluene, and diethyl ether.

[0018] Based on the above technical solution, the preparation method of the metal complex-carbonyl catalyst of the organic nitrogen-containing polymer further includes the following steps: under an inert atmosphere, the metal complex of the organic nitrogen-containing polymer is dispersed in a solvent, a metal carbonyl compound precursor is added, and the mixture is stirred at -80 to 100°C for 5-72 hours. After washing, filtering, and drying, the metal complex-carbonyl catalyst of the organic nitrogen-containing polymer is obtained. The metal carbonyl compound precursor is one of Na[Co(CO)4] and K[Co(CO)4]. The solvent is one of tetrahydrofuran, 1,4-dioxane, and ethylene glycol dimethyl ether.

[0019] Based on the above technical solution, the preparation process of the metal complex of the organic nitrogen-containing polymer further includes the following steps: under an inert atmosphere, the organic nitrogen-containing polymer is dispersed in a solvent, a coordinated metal precursor is added, and the mixture is impregnated and stirred at 20-100℃ for 1-48 hours. After drying, the metal complex of the organic nitrogen-containing polymer is obtained. The solvent is one or a mixture of two or more of methanol, ethanol, water, N-methylpyrrolidone, and toluene.

[0020] Based on the above technical solution, the preparation process of the organic nitrogen-containing polymer further includes the following steps: adding azobisisobutyronitrile (AIBN) as a free radical initiator to an organic solvent containing a vinyl nitrogen-containing monomer; transferring the solvent to a hydrothermal reactor and allowing it to stand at 333–423 K for 1–100 hours to carry out a polymerization reaction; and drying the solvent to obtain the organic nitrogen-containing polymer, wherein the weight ratio of the vinyl nitrogen-containing monomer to the free radical initiator is 0.5:1–100:1.

[0021] Based on the above technical solution, the organic solvent is further selected from dimethylformamide, dimethylacetamide, dichloromethane, and dimethyl sulfoxide.

[0022] This invention also provides the application of a composite catalyst for the preparation of β-lactone by epoxide ring expansion carbonylation in the catalytic preparation of β-lactone from epoxides.

[0023] Based on the above technical solution, the reactor used in the preparation of β-lactone is a batch reactor; the CO pressure is 1-7.0 MPa; and the reaction temperature is 40-70℃.

[0024] Based on the above technical solution, further, the epoxide is ethylene oxide (EO) and propylene oxide (PO) or 1,2-epoxybutane (BO), the molar ratio of epoxide to catalyst is 100-5000; the reaction time is 1-12 h; and the reaction solvent is one of ethylene glycol dimethyl ether, tetrahydrofuran, toluene, and 1,4-dioxane.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The activity of heterogeneous carbonylation catalysts for epoxy compounds is generally worse than that of homogeneous catalysts. This may be due to the diffusion and mass transfer processes involved in the reaction in heterogeneous catalysts, or the different rate-determining steps in the heterogeneous and homogeneous carbonylation mechanisms. Therefore, adding promoters that can improve activity is one of the important strategies to solve the problem of poor activity of heterogeneous carbonylation catalysts. The catalyst of this invention incorporates a quaternized or quaternized porous organic cage, wherein the promoter contains the cation P + Or N + It can accelerate the ring-opening of epoxides and speed up the carbonylation rate.

[0027] (2) Generally, porous organic cages containing P and N have good solubility and can be dissolved in a variety of solvents. However, there are few reports on quaternized or quaternized porous organic cages, and they are insoluble in most solvents and cannot be dispersed in solvents, especially in commonly used solvents for the carbonylation of epoxides, such as tetrahydrofuran and ethylene glycol dimethyl ether. This invention develops a series of quaternized or quaternized porous organic cages that are soluble in or highly dispersed in the carbonylation reaction system, solving the above-mentioned key problems. It successfully introduces quaternized or quaternized porous organic cages as auxiliaries into the carbonylation reaction of epoxides in a homogeneous or highly dispersed form, thereby obtaining better carbonylation performance.

[0028] (3) For quaternized or quaternized porous organic cages that are soluble in the reaction solution, after carbonylation, the quaternized or quaternized porous organic cages dissolved in the reaction solution can be precipitated from the reaction solution by introducing MeOH, which makes them easy to separate from the reaction solution and recycle.

[0029] (4) Currently reported ligands for the Lewis acid moiety of heterogeneous catalysts are mainly porphyrins or Schiff base derivatives, with other ligands rarely reported. In this invention, novel nitrogen-containing pyridine and phenanthrene ligands are used as ligands in Lewis acid, and the synthesized catalyst exhibits excellent carbonylation activity of epoxides. Attached Figure Description

[0030] To more clearly illustrate the embodiments of the present invention, the accompanying drawings involved in the embodiments will be briefly described below.

[0031] Figure 1 The activity and selectivity of the catalysts in Examples 3 and 17 for different cycles in the carbonylation reaction of PO. Detailed Implementation

[0032] The present invention will be described in detail below with reference to the embodiments. However, the implementation of the present invention is not limited thereto. Obviously, the embodiments described below are only some embodiments of the present invention. For those skilled in the art, other similar embodiments can be obtained without creative effort and all fall within the protection scope of the present invention.

[0033] The structures of the compounds involved in the examples are shown below:

[0034]

[0035]

[0036] The synthesis methods of the above compounds AD are described in the references (Catalysis Today (2017), 298, 40-45); the synthesis method of EH is described in the references (Organic & Biomolecular Chemistry (2014), 12(8), 1232-1236, Bioorganic & Medicinal Chemistry Letters (2018), 28(5), 926-929); the synthesis method of IN is described in the references (Tetrahedron, 2009, 65(1): 305-311); the synthesis of OT is described in the references (Journal of Catalysis (2019), 369, 249-256).

[0037] Example 1

[0038] Under inert atmosphere at room temperature, 342 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 692 mg of compound A. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-1. 0.926 g of porous organic cage-1 was weighed and dissolved in THF. 3.71 g of quaternizing reagent K was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-1.

[0039] Example 2

[0040] 0.926 g of porous organic cage-1 was weighed and dissolved in THF. 2.71 g of quaternizing reagent J was added, and the mixture was refluxed and stirred for 48 h. After the reaction was completed, the mixture was dried to obtain quaternized porous organic cage-2.

[0041] Example 3

[0042] Under inert atmosphere at room temperature, 228 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 424 mg of compound B. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-2. 0.975 g of porous organic cage-2 was weighed and dissolved in THF. 3.71 g of quaternizing reagent K was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-3.

[0043] Example 4

[0044] 0.975 g of porous organic cage-2 was weighed and dissolved in THF. 2.71 g of quaternizing reagent J was added, and the mixture was refluxed and stirred for 48 h. After the reaction was completed, the mixture was dried to obtain quaternized porous organic cage-4.

[0045] Example 5

[0046] Weigh 0.975 g of porous organic cage-2 and dissolve it in THF. Add 2.90 g of quaternizing reagent N, reflux and stir for 48 h. After the reaction is complete, dry the mixture to obtain quaternized porous organic cage-5.

[0047] Example 6

[0048] Under inert atmosphere at room temperature, 342 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 736 mg of compound C. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-3. 0.970 g of porous organic cage-3 was weighed and dissolved in THF. 3.06 g of quaternizing reagent L was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-6.

[0049] Example 7

[0050] Under inert atmosphere at room temperature, 342 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 692 mg of compound D. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-4. 0.926 g of porous organic cage-2 was weighed and dissolved in THF. 3.71 g of quaternizing reagent K was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-7.

[0051] Example 8

[0052] Under inert atmosphere at room temperature, 342 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 658 mg of compound E. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-5. 0.892 g of porous organic cage-5 was weighed and dissolved in THF. 3.71 g of quaternizing reagent K was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-8.

[0053] Example 9

[0054] Under inert atmosphere at room temperature, 228 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 462 mg of compound F. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-6. 0.732 g of porous organic cage-6 was weighed and dissolved in THF. 2.26 g of quaternizing reagent I was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-9.

[0055] Example 10

[0056] Under inert atmosphere at room temperature, 342 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 637 mg of compound G. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-7. 0.927 g of porous organic cage-7 was weighed and dissolved in THF. 2.71 g of quaternizing reagent J was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-10.

[0057] Example 11

[0058] Under inert atmosphere at room temperature, 342 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 658 mg of compound H. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-8. 0.892 g of porous organic cage-8 was weighed and dissolved in THF. 2.90 g of quaternizing reagent M was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-11.

[0059] Example 12

[0060] Under a protective atmosphere of 298 K and Ar, 10.0 g of nitrogen-containing monomer P was dissolved in 100.0 mL of dimethylformamide solvent. 0.25 g of azobisisobutyronitrile (AIBN) as a free radical initiator was added to the solution, and the mixture was stirred for 2 hours. The stirred solution was transferred to a hydrothermal reactor and polymerized at 373 K and Ar under a protective atmosphere using a solvothermal method for 48 hours. After the polymerized solution was cooled to room temperature, the solvent was removed under vacuum at room temperature, yielding an organic nitrogen-containing polymer support-1 with a large surface area and hierarchical porous structure. Then, under a protective atmosphere of 298 K and N2, 0.044 g of Cr(OAc)3 was dissolved in 50 mL of hot water and 50 mL of ethanol. 1 g of the organic nitrogen-containing polymer support-1 was added to the solution, and the mixture was stirred at room temperature for 24 hours. After washing with ethanol and water and filtering, the solvent was removed under vacuum, yielding a metal complex of the organic nitrogen-containing polymer. The Cr content was determined to be 1% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran solvent, and then the metal complex of the above-mentioned organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-1. The Co content was determined to be 1% by ICP-OES.

[0061] Example 13

[0062] Under a protective atmosphere of 298 K and N2, 0.0756 g of Al(OAc)3 was dissolved in 50 mL of ethanol, and then 1 g of the organic nitrogen-containing polymer support-1 from Example 12 was added. The mixture was stirred at room temperature for 24 h, washed with ethanol and filtered, and the solvent was removed under vacuum to obtain the metal complex of the organic nitrogen-containing polymer. The Al content was measured to be 0.5% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran solvent, and then the above-mentioned metal complex of the organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-2. The Co content was measured to be 1% by ICP-OES.

[0063] Example 14

[0064] Under a protective atmosphere of 298 K and N2, 0.0598 g of Al2(C2O4)3 was dissolved in 50 ml of dilute hydrochloric acid, and then 1 g of the organic nitrogen-containing polymer support-1 from Example 12 was added. The mixture was stirred at room temperature for 24 h, washed with ethanol and filtered, and the solvent was removed under vacuum to obtain the metal complex of the organic nitrogen-containing polymer. The Al content was measured to be 0.5% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran solvent, and then the above-mentioned metal complex of the organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-3. The Co content was measured to be 1% by ICP-OES.

[0065] Example 15

[0066] Under a protective atmosphere of 298 K and N2, 0.0183 g of Cr2(C2O4)3·6H2O was dissolved in 50 ml of water, and then 1 g of the organic nitrogen-containing polymer support-1 from Example 12 was added. The mixture was stirred at room temperature for 24 h, washed with ethanol and filtered, and the solvent was removed under vacuum to obtain the metal complex of the organic nitrogen-containing polymer. The Cr content was determined to be 1% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran solvent, and then the above-mentioned metal complex of the organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-4. The Co content was determined to be 1% by ICP-OES.

[0067] Example 16

[0068] Under a protective atmosphere of 298 K and N2, 0.0396 g of TiCl4 was dissolved in 50 ml of toluene, and then 1 g of the organic nitrogen-containing polymer support-1 from Example 12 was added. The mixture was stirred at room temperature for 24 h, washed with ethanol and filtered, and the solvent was removed under vacuum to obtain the metal complex of the organic nitrogen-containing polymer. The Ti content was determined to be 1% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in 1,4-dioxane, and then the above-mentioned metal complex of the organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-5. The Co content was determined to be 1% by ICP-OES.

[0069] Example 17

[0070] Under a protective atmosphere of 298 K and N2, 0.0878 g of Al(OTf)3 was dissolved in 50 ml of methanol, and then 1 g of the organic nitrogen-containing polymer support-1 from Example 12 was added. The mixture was stirred at room temperature for 24 h, washed with ethanol and filtered, and the solvent was removed under vacuum to obtain the metal complex of the organic nitrogen-containing polymer. The Al content was measured to be 0.5% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran, and then the above-mentioned metal complex of the organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-6. The Co content was measured to be 1% by ICP-OES.

[0071] Example 18

[0072] Under a protective atmosphere of 298 K and Ar, 10.0 g of nitrogen-containing monomer O was dissolved in 100.0 ml of dimethylformamide solvent. 0.25 g of azobisisobutyronitrile (AIBN) as a free radical initiator was added to the solution, and the mixture was stirred for 2 hours. The stirred solution was transferred to a hydrothermal reactor and polymerized at 373 K and Ar under a protective atmosphere using a solvothermal method for 48 hours. After the polymerized solution was cooled to room temperature, the solvent was removed under vacuum at room temperature, yielding a large-surface-area, hierarchical porous organic nitrogen-containing polymer support-2. Then, under a protective atmosphere of 298 K and N2, 0.072 g of CrCl3·3THF was dissolved in 50 ml of tetrahydrofuran, and 1 g of the organic nitrogen-containing polymer support-2 was added. The mixture was stirred at room temperature for 24 hours. After washing and filtering with tetrahydrofuran, the solvent was removed under vacuum, yielding a metal complex of the organic nitrogen-containing polymer. ICP-OES analysis showed a Cr content of 1%. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in 1,4-dioxane solvent, and then the metal complex of the above-mentioned organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-7. The Co content was determined to be 1% by ICP-OES.

[0073] Example 19

[0074] Under a protective atmosphere of 298 K and Ar, 10.0 g of nitrogen-containing monomer S was dissolved in 100.0 ml of dimethylformamide solvent. 0.25 g of azobisisobutyronitrile (AIBN) as a free radical initiator was added to the solution, and the mixture was stirred for 2 hours. The stirred solution was transferred to a hydrothermal reactor and polymerized at 373 K and Ar under a protective atmosphere using a solvothermal method for 48 hours. After the polymerized solution was cooled to room temperature, the solvent was removed under vacuum at room temperature, yielding an organic nitrogen-containing polymer support-3 with a large surface area and hierarchical porous structure. Then, under a protective atmosphere of 298 K and N2, 0.0183 g of Cr2(C2O4)3·6H2O was dissolved in 50 ml of water, and 1 g of the organic nitrogen-containing polymer support-3 was added. The mixture was stirred at room temperature for 24 hours, washed with water, filtered, and the solvent was removed under vacuum, yielding a metal complex of the organic nitrogen-containing polymer. The Cr content was determined to be 1% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran, and then the metal complex of the above-mentioned organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-8. The Co content was determined to be 1% by ICP-OES.

[0075] Example 20

[0076] Under a protective atmosphere of 298 K and Ar, 10.0 g of nitrogen-containing monomer Q was dissolved in 100.0 ml of dimethylformamide solvent. 0.25 g of azobisisobutyronitrile (AIBN) as a free radical initiator was added to the solution, and the mixture was stirred for 2 hours. The stirred solution was transferred to a hydrothermal reactor and polymerized at 373 K and Ar under a protective atmosphere using a solvothermal method for 48 hours. After the polymerized solution was cooled to room temperature, the solvent was removed under vacuum at room temperature, yielding an organic nitrogen-containing polymer support-4 with a large surface area and hierarchical porous structure. Then, under a protective atmosphere of 298 K and N2, 0.0598 g of Al2(C2O4)3 was dissolved in 50 ml of dilute hydrochloric acid, and 1 g of the organic nitrogen-containing polymer support-4 was added. The mixture was stirred at room temperature for 24 hours, washed with water, filtered, and the solvent was removed under vacuum, yielding a metal complex of the organic nitrogen-containing polymer. ICP-OES analysis showed an Al content of 0.5%. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran, and then the metal complex of the above-mentioned organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-9. The Co content was determined to be 1% by ICP-OES.

[0077] Example 21

[0078] Under a protective atmosphere of 298 K and Ar, 10.0 g of nitrogen-containing monomer T was dissolved in 100.0 ml of dimethylformamide solvent. 0.25 g of azobisisobutyronitrile (AIBN) as a free radical initiator was added to the solution, and the mixture was stirred for 2 hours. The stirred solution was transferred to a hydrothermal reactor and polymerized at 373 K and Ar under a protective atmosphere using a solvothermal method for 48 hours. After the polymerized solution was cooled to room temperature, the solvent was removed under vacuum at room temperature, yielding a large-surface-area, hierarchical porous organic nitrogen-containing polymer support-5. Then, under a protective atmosphere of 298 K and N2, 0.0396 g of TiCl4 was dissolved in 50 ml of toluene, and 1 g of the organic nitrogen-containing polymer support-5 was added. The mixture was stirred at room temperature for 24 hours, washed with water, filtered, and the solvent was removed under vacuum, yielding a metal complex of the organic nitrogen-containing polymer. ICP-OES analysis showed that the Ti content was 1%. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in ethylene glycol dimethyl ether, and then the metal complex of the above-mentioned organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-10. The Co content was determined to be 1% by ICP-OES.

[0079] Example 22

[0080] Under a protective atmosphere of 298 K and Ar, 10.0 g of nitrogen-containing monomer R was dissolved in 100.0 ml of dimethylformamide solvent. 0.25 g of azobisisobutyronitrile (AIBN) as a free radical initiator was added to the solution, and the mixture was stirred for 2 hours. The stirred solution was transferred to a hydrothermal reactor and polymerized at 373 K and Ar under a protective atmosphere using a solvothermal method for 48 hours. After the polymerized solution was cooled to room temperature, the solvent was removed under vacuum at room temperature, yielding a large-surface-area, hierarchical porous organic nitrogen-containing polymer support-6. Then, under a protective atmosphere of 298 K and N2, 0.0494 g of AlCl3 was dissolved in 50 ml of anhydrous ethanol, and 1 g of the organic nitrogen-containing polymer support-6 was added. The mixture was stirred at room temperature for 24 hours, washed with water, filtered, and the solvent was removed under vacuum, yielding a metal complex of the organic nitrogen-containing polymer. ICP-OES analysis showed an Al content of 0.5%. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in 1,4-dioxane solvent, and then the metal complex of the above-mentioned organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst-11. The Co content was determined to be 1% by ICP-OES.

[0081] Comparative Example 1

[0082] Under inert atmosphere at room temperature, 342 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 692 mg of A. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-1. 0.926 g of porous organic cage-1 was weighed and dissolved in THF. 2.8 g of the quaternizing reagent iodomethane was added, and the mixture was refluxed and stirred for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-comparison 1.

[0083] Under a protective atmosphere of 298 K and N2, 0.0878 g of Al(OTf)3 was dissolved in 50 ml of methanol, and then 1 g of the organic nitrogen-containing polymer support-1 from Example 12 was added. The mixture was stirred at room temperature for 24 h, washed with ethanol and filtered, and the solvent was removed under vacuum to obtain the metal complex of the organic nitrogen-containing polymer. The Al content was measured to be 0.5% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran, and then the above-mentioned metal complex of the organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst - Comparative 1. The Co content was measured to be 1% by ICP-OES.

[0084] Comparative Example 2

[0085] Under inert atmosphere at room temperature, 228 mg of 1,2-cyclohexanediamine was dissolved in 30 mL of ethyl acetate and slowly added dropwise to 150 mL of ethyl acetate containing 424 mg of compound B. After the addition was complete, the mixture was allowed to stand for 96 h. After the reaction was complete, the insoluble substances were removed by filtration, and the mixture was concentrated under vacuum until a small amount of solvent remained. 100 mL of methanol was added, and the solid precipitated out. The solid was collected by filtration and dried under vacuum to obtain porous organic cage-2. 0.975 g of porous organic cage-2 was weighed and dissolved in THF. 2.8 g of the quaternizing reagent iodomethane was added, and the mixture was stirred under reflux for 48 h. After the reaction was complete, the mixture was dried under vacuum to obtain quaternized porous organic cage-comparison 2.

[0086] Under a protective atmosphere of 298 K and N2, 0.0878 g of Al(OTf)3 was dissolved in 50 ml of methanol, and then 1 g of the organic nitrogen-containing polymer support-1 from Example 12 was added. The mixture was stirred at room temperature for 24 h, washed with ethanol and filtered, and the solvent was removed under vacuum to obtain the metal complex of the organic nitrogen-containing polymer. The Al content was measured to be 0.5% by ICP-OES. Under an inert atmosphere, 0.0329 g of Na[Co(CO)4] was dissolved in tetrahydrofuran, and then the above-mentioned metal complex of the organic nitrogen-containing polymer was added. The mixture was stirred at -20 °C for 24 h, washed, filtered, and dried to obtain the final metal complex of the organic nitrogen-containing polymer - carbonyl catalyst - Comparative 2. The Co content was measured to be 1% by ICP-OES.

[0087] Example 23

[0088] Application of the metal complex-carbonylation catalysts of organic nitrogen-containing polymers prepared in Examples 1-22 and Comparative Examples 1-2 in the preparation of β-lactones from ethylene oxide, propylene oxide and 1,2-epoxybutane under the synergistic effect of porous organic cage promoters with or without cationic frameworks.

[0089] Reactor conditions: A certain mass of the nitrogen-containing polymer metal complex-carbonylation catalyst was weighed and added to a 50 mL reactor. 12 mL of ultra-dry THF was added, along with 1.56 g of ethylene oxide, 2.06 g of propylene oxide, or 2.56 g of 1,2-epoxybutane, where n... EO / n Co =200, n PO / n Co =200, n BO / n Co =200, the reactor is filled with 6.0 MPa of CO, and the reaction is carried out at 60°C for 3 hours.

[0090] Offline liquid chromatography was performed using a DB-1701 capillary column and an FID detector to analyze the content of epoxides and β-lactones.

[0091] The yield, selectivity, and TOF results of carbonylation of β-lactone prepared according to the above procedures are shown in Table 1.

[0092] Table 1. Results of epoxide carbonylation reactions catalyzed by catalysts in Examples 1-22 and Comparative Examples 1-2

[0093]

[0094]

[0095] Note: [a]n EO / n Co ;[b]n PO / n Co ;[c]n BO / n Co

[0096] In addition, the cyclic stability of the catalysts combined in Examples 3 and 17 was investigated. The reaction conditions were as follows: The reaction solution after the carbonylation of propylene oxide was filtered in a glove box, yielding an organic nitrogen-containing polymer metal complex – carbonyl catalyst-6 – in the filter cake. Excess MeOH was added to the filtrate, causing the quaternized porous organic cage-3 to precipitate from the filtrate. The quaternized porous organic cage-3 was recovered by filtration, and the product β-lactone was further separated from the filtrate under vacuum. The recovered organic nitrogen-containing polymer metal complex – carbonylation catalyst-6 and the quaternized porous organic cage-3 were added back to the reactor, along with the substrate propylene oxide. The reactor was purged with CO at 6.0 MPa, and the reaction was carried out at 60°C for 3 hours. The cyclic stability of the catalyst carbonylation was tested under the same conditions each time. The test results are as follows: Figure 1 As shown.

[0097] Comparison of results from examples and comparative examples revealed that the main catalyst, a metal complex of an organic nitrogen-containing polymer—carbonyl catalyst-6—exhibited the best activity under the synergistic effect of the auxiliary cationic framework porous organic cage-3. Furthermore, when n(auxiliary):n(co-catalyst) = 1:1, the auxiliary significantly improved the activity of the epoxide carbonylation system. A simple method was used to separate the auxiliary, main catalyst, and reaction solution, and the recovered auxiliary and main catalyst exhibited good cycle stability. The introduction of the auxiliary significantly improved the activity of the main catalyst, saved on catalyst preparation and separation costs, and further laid the foundation for the industrial application of epoxide heterogeneous carbonylation to β-lactone.

[0098] The present invention has been described in detail above, but it is not limited to the specific embodiments described herein. Other modifications and variations can be made without departing from the scope of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A method for preparing epoxides by ring-expansion carbonylation β A composite catalyst for -lactones, characterized in that, The composite catalyst comprises two parts: a quaternized or quaternized porous organic cage promoter and a metal complex-carbonyl catalyst of an organic nitrogen-containing polymer. The promoter is prepared by reacting a porous organic cage with a quaternizing or quaternizing agent. The porous organic cage is prepared by reacting an aldehyde-containing nitrogen- or phosphine-containing monomer with 1,2-cyclohexanediamine. The metal complex-carbonyl catalyst of the organic nitrogen-containing polymer comprises a metal complex of the organic nitrogen-containing polymer and a metal carbonyl compound. The metal complex of the organic nitrogen-containing polymer consists of an organic nitrogen-containing polymer support and a coordinated metal species. The organic nitrogen-containing polymer support is prepared by free radical polymerization of a vinyl-containing nitrogen-containing monomer. The coordinated metal of the organic nitrogen-containing polymer support is one of Cr, Al, or Ti, and the precursor of the metal carbonyl compound is M. 1 x [M 2 (CO) w ], where M 1 M is an alkali metal. 2 The catalyst is composed of Co, with x = 1 and w = 4; the coordinated metal accounts for 0.01–5.0 wt% of the total catalyst mass; Co accounts for 0.01–5.0 wt% of the total catalyst mass. The aldehyde-containing nitrogen- or phosphine-containing monomer is one of the following compounds AH; the quaternizing agent or quaternizing agent is one of the following compounds IN; 。 2. The composite catalyst according to claim 1, characterized in that, The coordinated metal accounts for 0.2–3.0 wt% of the total mass of the catalyst; Co accounts for 0.2–3.0 wt% of the total mass of the catalyst.

3. The composite catalyst according to claim 1, characterized in that, The vinyl-containing nitrogen-containing monomer is one of the following compounds, OT; the coordinated metal precursor is TiCl4, Cr(OAc)3, or Cr2(C2O4)3. 6H2O, CrCl3 One of 3THF, Al(OAc)3, Al2(C2O4)3, or AlCl3; 。 4. The method for preparing the composite catalyst according to any one of claims 1-3, characterized in that, The catalyst is obtained by uniformly mixing two parts: a quaternized or quaternized porous organic cage promoter and a metal complex-carbonyl catalyst of an organic nitrogen-containing polymer. The molar ratio of the quaternized or quaternized porous organic cage promoter and the metal complex-carbonyl catalyst of the organic nitrogen-containing polymer is 10:1 to 1:

10.

5. The preparation method according to claim 4, characterized in that, The preparation method of the aforementioned additive includes the following steps: under an inert atmosphere, adding a porous organic cage material and one of the quaternizing or quaternizing reagents IN to a solvent, and then reacting the mixture at a temperature of -80 to 100°C. o Stirred at C for 5-72 h, concentrated by rotary evaporation, filtered and dried to obtain a porous organic cage with quaternized or quaternized phosphoric acid; wherein the molar ratio of P or N to the quaternizing or quaternizing reagent in the porous organic cage is 1:1 to 1:20; the solvent is one or more of ethylene glycol dimethyl ether, tetrahydrofuran, tetrahydropyran, 2-methyltetrahydrofuran, and 1,4-dioxane.

6. The preparation method according to claim 5, characterized in that, The preparation method of the porous organic cage material includes the following steps: under an inert atmosphere, one of the nitrogen-containing or phosphine-containing monomers AH containing an aldehyde group and 1,2-cyclohexanediamine are added to a solvent, and the mixture is heated at 0~100 °C. o The reaction is carried out at C for 24-120 h. The sparingly soluble substances are removed by filtration. The filtrate is concentrated, methanol is added to precipitate the solid, and the solid is obtained by filtration and washing to obtain a porous organic cage material. The molar ratio of the nitrogen-containing or phosphine-containing monomer containing an aldehyde group to 1,2-cyclohexanediamine is 1:1 to 1:

5. The solvent is one or more of ethyl acetate, n-hexane, cyclohexane, toluene, and diethyl ether.

7. The preparation method according to claim 4, characterized in that, The preparation method of the metal complex-carbonyl catalyst of the organic nitrogen-containing polymer includes the following steps: dispersing the metal complex of the organic nitrogen-containing polymer in a solvent under an inert atmosphere, adding a metal carbonyl compound precursor, and reacting the catalyst at a temperature of -80 to 100°C. o Stirred at C for 5-72 h, washed, filtered, and dried to obtain a metal complex-carbonyl catalyst of organic nitrogen-containing polymer; the metal carbonyl compound precursor is one of Na[Co(CO)4] and K[Co(CO)4]; the solvent is one of tetrahydrofuran, 1,4-dioxane, and ethylene glycol dimethyl ether.

8. The preparation method according to claim 7, characterized in that, The preparation process of the metal complex of the organic nitrogen-containing polymer includes the following steps: dispersing the organic nitrogen-containing polymer in a solvent under an inert atmosphere, adding a coordinated metal precursor, and then... o C is impregnated and stirred for 1-48 h to obtain a metal complex of an organic nitrogen-containing polymer, wherein the solvent is one or a mixture of two or more of methanol, ethanol, water, N-methylpyrrolidone, and toluene. The preparation process of the organic nitrogen-containing polymer includes the following steps: adding azobisisobutyronitrile (AIBN) as a free radical initiator to an organic solvent containing a vinyl nitrogen-containing monomer; transferring the mixture to a hydrothermal reactor and allowing it to stand at 333-423 K for 1-100 hours to carry out a polymerization reaction to obtain the organic nitrogen-containing polymer, wherein the weight ratio of the vinyl nitrogen-containing monomer to the free radical initiator is 0.5:1-100:1; and the organic solvent is one of dimethylformamide, dimethylacetamide, dichloromethane, and dimethyl sulfoxide.

9. The composite catalyst according to any one of claims 1-3 in the catalytic preparation of epoxides β - Applications in lactones.

10. The application according to claim 9, characterized in that, preparation β - The reactor used in the lactone process is a batch reactor; the CO pressure is 1~7.0 MPa; the reaction temperature is 40~70 ℃; the epoxide is ethylene oxide, propylene oxide or 1,2-epoxidebutane, and the molar ratio of epoxide to catalyst is 100~5000; the reaction time is 1~12 h; the reaction solvent is one of ethylene glycol dimethyl ether, tetrahydrofuran, toluene or 1,4-dioxane.

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