554 results about "Cycloaddition" patented technology

The invention relates to Omarlliptin, in particular to a novel method for preparing Istradafylline, and relates to a preparation method of Istradafylline, in particular to a preparation method of Istradafylline. The method comprises the following steps: carrying out coupling reaction on a compound Ia and TMS acetylene to obtain an intermediate Ib; carrying out bromination reaction on the intermediate Ic under the action of NBS (N-bromosuccinimide) to obtain an intermediate Id; carrying out substitution reaction on the intermediate Id and tert-butyl carbamate under the action of potassium tert-butoxide to obtain an intermediate Ie; reacting the intermediate Ie with paraformaldehyde to obtain an intermediate If; carrying out cycloaddition reaction on the intermediate If and the intermediate Ib to obtain a key intermediate Ig; carrying out asymmetric catalytic hydrogenation reduction on the intermediate Ig to obtain an intermediate Ih; and removing a protecting group from the intermediate Ih in a hydrochloric acid and ethyl acetate system to obtain a final product. The method is short in route, simple and convenient to operate, mild in condition, high in reaction yield, environment-friendly and easy for industrial production, and dangerous and highly toxic products are prevented from being used and hazardous chemicals are supervised. # imgabs0 #

The invention provides a method for preparing squaric acid and a method for preparing a lithium supplement agent of lithium squarate. The method for preparing squaric acid comprises the steps of preparing an intermediate I, preparing an intermediate II and preparing squaric acid. The method for preparing the squaric acid is a novel squaric acid synthesis route, and the squaric acid is obtained through cycloaddition / substitution reaction of perchloroprene serving as an initial raw material and morpholine, hydrolysis / rearrangement reaction in a buffer system and acid hydrolysis reaction in sequence. The method for preparing squaric acid has the advantages of simple reaction steps, mild reaction conditions, high yield, low cost and the like. The invention also provides a method for preparing the lithium squarate lithium supplement agent, and the prepared squaric acid and lithium-containing alkali are blended in a solvent for reaction to generate the lithium squarate. The method for preparing the lithium squarate lithium supplement has the advantages of simple reaction steps, mild reaction conditions, high yield, low cost and the like.

The invention discloses a sgRNA-based method for modifying and regulating gene editing, which comprises the following steps: carrying out POC acylation modification on a 2 '-OH site of sgRNA to introduce an alkynyl marker to obtain sgRNA with alkynyl; the sgRNA with alkynyl and azide are subjected to copper-catalyzed azide-alkynyl cycloaddition reaction under the action of a copper catalytic reagent to form a stable chemical cross-linked structure, so that the activity of the sgRNA is quickly closed and adjusted. According to the method, alkynyl is introduced to sgRNA and is subjected to a CuAAC reaction with multi-azide to form stable crosslinking, so that the activity of the CRISPR-Cas9 system is accurately controlled. The innovative method not only can effectively control the gene editing activity on the basis of not destroying the original structure and function of RNA, but also can significantly improve the target specificity of the CRISPR system and reduce the risk of genome damage caused by non-specific cleavage.

The invention discloses an amino-bridged triaryloxy rare earth metal complex and a preparation method and application thereof, the amino-bridged triaryloxy rare earth metal complex is prepared by reaction of a tricyclopentadienyl rare earth compound and amino-bridged triphenol, and the preparation method is simple to operate, convenient to separate and purify, low in raw material cost and mild in reaction condition. The amino-bridged triaryloxy rare earth metal complex provided by the invention can be used for catalytic oxidation of chalcone compounds and cycloaddition reaction of carbon dioxide, the reaction conditions are relatively mild, the universality of reaction substrates is wide, the reaction time is short, the yield of target products is high, and the reaction operation process is simple.

The invention relates to an organic acid anion paired polyion liquid catalyst as well as a preparation method and application thereof. Due to environmental pollution caused by halogen, a series of environment-friendly porous polyion liquid catalysts paired with organic acid anions are designed and synthesized, 1-vinyl imidazole and bis (2-chloroethyl) ether are used as raw materials, and the ionic liquid diethyl ether bis (1-vinyl imidazole) chloride is successfully prepared. Divinyl benzene is selected as a cross-linking agent and a structure stabilizer, and a stable copolymer is prepared. The copolymer is put into a sodium hydroxide solution to react for three days, hydroxyl replaces chloride anions to obtain a substance [ECD] OH, the [ECD] OH is put into an organic acid solution to react for three days, and finally, organic acid anions replace halogen anions, so that the pollution to the environment is reduced. The series of catalysts are stable in structure, and can efficiently catalyze carbon dioxide cycloaddition to generate cyclic carbonate under the conditions of no solvent and no cocatalyst.

This disclosure provides a method of tagging binders in electrodes to allow for easy visualization. In particular, environmentally friendly organic molecules are used as organic fluorescent tags. The organic fluorescent tag will react with alkene moieties within the binder through cycloadditions to introduce a fluorescent tag, which is easily visualized to allow visualisation of binder distribution within the electrode.

The invention provides a pyrrolidone dihydroisoxazole compound as well as a preparation method and application thereof, and belongs to the technical field of organic synthesis. Specifically, under the catalytic action of Lewis base, beta-oxoacrylamide and 4-nitroisoxazole serve as raw materials, and the pyrrolidone dihydroisoxazole compound is synthesized through a one-step method. Beta-oxoacrylamide and 4-nitroisoxazole which are simple and easy to obtain are adopted as starting raw materials, dearomatization [3 + 2]-cycloaddition reaction is carried out under the catalysis of Lewis base, the pyrrolidone dihydroisoxazole compound is synthesized, the method is easy and convenient to operate and mild in reaction condition, the used reagents and raw materials are economical and easy to obtain, and the method is suitable for industrial production. The target product yield is high, the substrate application range is wide, and the in-vitro anti-tumor activity is good.

The invention relates to the technical field of functional materials, in particular to a metal-DNA aptamer self-assembled nano material as well as a preparation method and application thereof. The metal-DNA aptamer self-assembled nano material comprises two DNA aptamers, a copper source and ascorbic acid, wherein the two DNA aptamers are used for modifying an azide group and an alkynyl group respectively; and copper is coordinated with a five-membered ring formed by a reaction through a copper-catalyzed azide-alkynyl cycloaddition reaction, so that the Cu-DNA aptamer self-assembled nano material is obtained. The problem that an existing metal-DNA self-assembly nanometer material cannot stably exist in a physiological environment is solved, and meanwhile, the application of the metal-DNA self-assembly nanometer material in chemokinetic tumor treatment is achieved by precisely recognizing tumor cells in a targeted mode.

The present invention discloses a metal porphyrin-based porous ionic polymer and a preparation method and application thereof, and relates to the technical field of polymer compound catalysis. The metal porphyrin-based porous ionic polymer of the present invention is provided with a three-dimensional structure by introducing tetraphenylmethane and its derivatives or halogen-containing phosphonium salts, thereby obtaining a metal porphyrin-based porous ionic polymer rich in mesopores and having a high specific surface area, thereby improving the catalytic performance and achieving efficient and highly selective catalytic reactions. The metal porphyrin-based porous ionic polymer prepared by the present invention is particularly suitable for catalyzing the cycloaddition reaction of carbon dioxide and epoxide, has high selectivity and strong adsorption capacity for carbon dioxide, and can catalyze the generation of cyclic carbonates efficiently and selectively.

The invention belongs to the technical field of organic synthesis and medicinal chemistry, and discloses a total synthesis method of rhododendron heteroterpenin Rhododaurines A-C. The total synthesis method comprises the following steps: carrying out allyl stereoselective addition on a compound 3 and a compound 5 in a toluene solvent under the conditions of catalysis of n-butyllithium and low temperature of-78 DEG C, and constructing a chiral center to obtain a compound 6; removing a methoxy methyl (MOM) protecting group from the compound 6 under an acidic condition, cyclizing, and reacting to generate rhododaurine C (7); the rhododaurine C (7) is subjected to intramolecular [4 + 2] cycloaddition and oxidation reaction in the illumination and oxygen atmosphere of 300-385 nm, and rhododaurine B (8) and an epoxy epimer epinedodaurine B (9) are obtained; and carrying out protonation and rearrangement on the epidodaurine B (9) by virtue of acid catalysis cyclic ether, so as to generate the rhododaurine A (10). The method can overcome the defects that the content of rhododendron miscellaneous terpenoids Rhododaurines A-C in nature is extremely low, and large-scale extraction is difficult.

The invention relates to an improved UiO-66 synthesis process based on a nitrogen-containing ligand. A metal organic framework material with high specific surface area, thermal stability, chemical stability and mechanical stability is synthesized through a solvothermal method. The specific preparation process comprises the following steps: mixing 4-aminomethyl benzoic acid (4-(Aminomethyl) benzoic acid (AMBA) with terephthalic acid (1, 4-dicarboxybenzene, H2BDC) and zirconium tetrachloride (ZrCl4) according to a certain ratio, transferring the mixture into a crystallization kettle, and synthesizing, so as to obtain the nitrogen modified UiO-66 with different contents, which is recorded as UiO-66-AMBAX. According to the method, the catalysts of the nitrogen-modified UiO-66 with different contents are used for the CO2 cycloaddition reaction, the catalyst shows excellent conversion rate and selectivity, and the reaction conditions are mild.

The invention discloses an organic phosphorescent material intermediate for an OLED (Organic Light Emitting Diode) as well as a preparation method and application of the organic phosphorescent material intermediate, and relates to the field of organic phosphorescent materials. The intermediate is prepared through a Diels-Alder cycloaddition reaction between trans-cyclooctene and 3, 6-diphenyltetrazine, the reaction is carried out under the conditions that the temperature is 20-30 DEG C and the time is 10-30 minutes, and the mass ratio of the trans-cyclooctene to the 3, 6-diphenyltetrazine is 1: (1.0-2.5). Trans-cyclooctene is prepared by isomerizing cis-cyclooctene under the irradiation of 254nm ultraviolet light in the presence of a photosensitizer; the 2, 3, 6-diphenyl tetrazine is prepared by condensation, cyclization and purification of benzaldehyde and benzoyl hydrazine. The purity of the prepared intermediate reaches up to 99.2%, the yield reaches 82.4%, the intermediate serving as an OLED luminescent material has excellent thermal stability, and the quantum efficiency is still kept at 90.1% after HTHH treatment is conducted for 1000 h. The invention provides a new intermediate choice for developing a high-performance OLED (Organic Light Emitting Diode) material.

The invention discloses a preparation method and application of a catalyst based on pyridine ionic liquid, and belongs to the technical field of catalyst preparation. According to the invention, a hydrolysis reaction of a silane coupling agent is utilized to prepare a silicon oxide nanotube containing a pyridine unit, and then a quaternization reaction is carried out to obtain the catalyst based on the pyridine ionic liquid. The catalyst has a high specific surface area and a rich pore channel structure, exposure of active sites and contact of the active sites and reactants are facilitated, and the catalytic rate is increased. Meanwhile, the silicon oxide nanotube contains hydroxyl, and can cooperate with a pyridine ionic liquid site to catalyze a carbon dioxide cycloaddition reaction. The obtained catalyst can catalyze the reaction of carbon dioxide and an epoxy compound to prepare cyclic carbonate under solvent-free and metal-free conditions, and the catalyst is easy to recover and simple in product purification, and has a good application prospect.

The invention discloses a method for synthesizing a porphyrin-based MOLs composite material by taking a lamellar oxide as a self-sacrifice template, and the method specifically comprises the following steps: preparing a lamellar oxide nanosheet NS-MO, and dispersing the NS-MO in deionized water to obtain an NS-MO suspension; porphyrin ligands with different metal centers are prepared and marked as TCPP (M); the preparation method comprises the following steps: dissolving TCPP (M) in an N, N-dimethylformamide solution, carrying out ultrasonic treatment until the TCPP (M) is completely dissolved, then adding the TCPP (M) into an NS-MO turbid liquid, adding DMF and H2O, and carrying out reaction, centrifugation, washing and vacuum drying in an ultrasonic reactor to obtain the porphyrin-based MOLs composite material. The invention also discloses an application of the porphyrin-based MOLs composite material in a CO2 cycloaddition reaction. According to the porphyrin-based MOLs composite material prepared by the invention, more accessible active sites can be exposed by the porphyrin-based MOLs composite material, and the porphyrin-based MOLs composite material is in contact with substrate molecules as far as possible, so that the catalytic activity is improved.

The invention provides a fiber type polyionic liquid catalyst and a preparation method and application thereof, the fiber type polyionic liquid catalyst is prepared by spinning a precursor solution, and the precursor solution is prepared by dissolving an ionic liquid monomer, an initiator, a cross-linking agent and a polymer raw material in a solvent and mixing. A specific precursor solution is spun to obtain a polyion liquid catalyst with a fiber structure and high porosity, and the polyion liquid catalyst has a microporous network, can enhance gas and mass transport, enables catalytic active sites to be effectively exposed, and can catalyze CO2 cycloaddition to generate cyclic carbonate under the mild conditions of no metal, no catalyst promoter and no solvent; and the catalyst has high catalytic activity and good cycle performance. The fiber type polyion liquid catalyst has processability, can still keep high catalytic activity after continuously catalyzing CO2 cycloaddition reaction for 1000 hours in micro continuous flow reactors (such as fixed beds) and the like, and has a wide industrial application prospect.

The invention aims to provide a method for preparing micron-sized zinc metastannate by wet recovery of tin and zinc in electronic wastes and a synthetic method of 4-hydroxy-1-indanone, and belongs to the technical field of metal recycling. According to the method, amino coordination and carboxylic acid chelation are utilized, tin and zinc in the electronic waste are selectively leached out under the mild acidic condition, impurity metals such as iron and copper are retained in residues due to the difference of complexing constants, and metal ion grade separation (selectivity gt and 99%) is achieved. And then, through evaporation-crystallization regulation and control, the Sn-Zn complex is directionally reconstructed into micron-sized zinc metastannate. In indanone synthesis, micron-sized zinc metastannate forms a local protonic acid environment by adsorbing trace moisture in a reaction system, synchronously activates a C = N bond (Lewis acid site catalysis) of an imine substrate and stabilizes a cyclization transition state (hydrogen bond guiding effect), so that the activation energy of [4 + 1] cycloaddition reaction is reduced, reaction equilibrium is driven to move towards a product end, and the yield of indanone is increased. And quantitative conversion of indanone under mild conditions (the yield is 60%) is realized.

The invention discloses application of a sulfonamide ionic liquid catalyst system in preparation of cyclic carbonate, sulfonamide ionic liquid comprises cations and anions, and the cations are one or more of tetra-alkyl ammonium ions, tetra-alkyl phosphonium ions and trimethyl hydroxyethyl ammonium ions; the anion is one or more of sulfonamide ions or substituted sulfonamide ions; the sulfonamide ionic liquid is used as a catalyst and is used for catalyzing CO2 to react with an epoxy compound to prepare cyclic carbonate; the catalyst is easy to prepare and high in catalytic activity, under normal pressure, the dosage of the catalyst is 1-3 mol%, the reaction time is 1-48 hours, the reaction temperature is 25-100 DEG C, and a substituted epoxy compound can be converted into corresponding cyclic carbonate with high conversion rate and high selectivity. After the catalyst system is recycled for five times, the catalytic effect is not obviously reduced. Meanwhile, the catalyst system has good universality to substrates, and conversion of various epoxy compounds can be efficiently achieved.

The invention discloses a brush-like polymer polypeptide drug delivery system and a preparation method and application thereof, and belongs to the technical field of polymer chemistry and biological medicines.The brush-like polymer polypeptide drug delivery system is obtained by a click reaction or a cycloaddition reaction of a polydisulfide main chain, a modified polypeptide drug and a polybetaine polymer, through the unique brush-shaped structure of the brush-shaped polymer, the polypeptide drug can be effectively protected from being degraded for a long time, the transmembrane transport and permeability of the polypeptide drug are improved, the technical scheme provides a new solution for clinical application of the polypeptide drug, and the polypeptide drug can be used for treatment of various diseases, especially diabetes mellitus or research and development of vaccines.

The invention discloses preparation and application of an amido-functionalized polyionic liquid catalyst, vinyl imidazole hydrobromide and N-(4-vinyl) benzyl diethylamine are used as monomers, N, N '-methylene bisacrylamide is used as a cross-linking agent, and the amido-functionalized polyionic liquid catalyst is prepared through a free radical copolymerization method. The imidazole / amido functionalized cross-linked PILs with multiple active sites are prepared by one-step synthesis through a hydrothermal polymerization method. The catalyst has catalytic active sites of amido, imidazolyl and Br, so that the catalyst can efficiently catalyze the cycloaddition reaction of CO2 and epoxide at 80 DEG C and normal pressure in the absence of a solvent and a co-catalyst.

The invention relates to the field of chemistry or medicinal chemistry, in particular to a synthesis method of isoxazoline anti-parasitic drug lotirasodium. The synthesis method comprises the following steps: firstly, synthesizing an intermediate 1 (1, 2, 3-trichloro-5-(1-trifluoromethyl-vinyl) benzene); then synthesizing an intermediate 2 (5-bromo-4-methyl-2-thiophenecarboxime); the preparation method comprises the following steps: carrying out a 1, 3 dipolar cycloaddition reaction on an intermediate 1 and an intermediate 2 in sequence to obtain an intermediate 3, carrying out a Grignard reaction to obtain racemic acid, and finally carrying out chemical resolution and amide condensation in sequence to obtain lotirasodium. According to the novel synthesis method of the isoxazoline anti-parasitic drug lotirazine, wittig reaction is adopted for the first time to obtain the intermediate 1, operation is simpler and more convenient, and reaction conditions are mild. Besides, the synthesis method of the intermediate 2 is improved, so that the reaction conditions are milder, the operation is simpler, the cost is greatly reduced on the basis of reported reaction conditions, and the method is suitable for industrialization.

The invention relates to the technical field of nano material preparation and application, and provides an Au-quasi UiO-66 composite material, a preparation method thereof and application of the Au-quasi UiO-66 composite material in photocatalytic CO2 cycloaddition. The preparation method comprises the following steps: preparing a UiO-66 material; preparation of a [Bmim] [AuCl4] coated UiO-66 material; and finally, the [Bmim] [AuCl4] coated UiO-66 material is subjected to direct pyrolysis, and the Au coated UiO-66 composite material is prepared. The obtained Au-quasi UiO-66 composite material has an ultrahigh specific surface, more active sites and excellent photo-thermal conversion performance, the utilization efficiency of light can be greatly improved, the catalytic performance can be improved, and the Au-quasi UiO-66 composite material has excellent catalytic performance in photocatalytic CO2 and epoxide cycloaddition reaction.

The invention relates to the technical field of catalytic synthesis, in particular to a solid acid catalyst and a preparation method thereof as well as a hydroxybutyl acrylate compound and a preparation method thereof. The solid acid catalyst comprises a binding material, a tin-doped molecular sieve carrier and acid, the tin-doped molecular sieve carrier is dispersed in the binding material and is loaded with the acid, and the acid comprises silicomolybdic acid and inorganic acid. The solid acid catalyst provided by the invention can be applied to catalysis of a ring-opening addition reaction of an acrylic acid compound and tetrahydrofuran, has moderate catalytic activity, and is beneficial to improvement of the conversion rate of tetrahydrofuran, reduction of self-polymerization of tetrahydrofuran, reduction of the selectivity of polytetrahydrofuran and improvement of the product selectivity of a hydroxybutyl acrylate compound.

The invention relates to the field of nutritional health food, and discloses a casein modified active peptide for promoting bone repair and a preparation method thereof.The structure of the active peptide sequentially comprises a bone targeting sequence with high affinity to hydroxyapatite, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions, a casein phosphopeptide core sequence capable of chelating calcium ions and a casein phosphopeptide core sequence capable of chelating calcium ions from the C-terminal to the N-terminal. The digestion sequence can be specifically hydrolyzed by matrix metalloproteinase, and the alkynyl functional group is used for covalent cross-linking. The active peptide can be mixed with an azido-containing multi-arm cross-linking agent, and hydrogel can be rapidly formed under physiological conditions through cycloaddition reaction. The system can be gelated in situ and anchored to a bone defect part in a targeted manner, and is triggered by a specific enzyme in a pathological microenvironment to controllably release active peptide fragments capable of chelating calcium ions, so that the concentration of local mineral ions is adjusted, the cell living environment is improved, and an effective new way is provided for promoting bone repair.

The invention relates to a method for synthesizing cyclic carbonate by catalyzing olefin oxidative carboxylation with a difunctional ionic liquid, which comprises the following steps: in a synthesis system, adding an oxidant and an additive into olefin serving as a raw material and the difunctional ionic liquid serving as a catalyst, and then carrying out epoxidation reaction; after the reaction is finished, potassium iodide and a carboxylation reagent are added into a reaction system, then cycloaddition reaction is performed, and finally cyclic carbonate can be prepared. The bifunctional ionic liquid is used as a catalyst, so that the olefin epoxidation reaction can be catalyzed, the cycloaddition reaction of an epoxide intermediate and CO2 can also be catalyzed, and the problem that a two-step reaction catalytic system is incompatible is solved. The adopted raw materials are cheap and easy to obtain, a metal-free catalyst is used, the method has the advantages of being economical and environmentally friendly, and an alternative scheme is provided for synthesis of cyclic carbonate.

The present invention relates to the field of the monitoring of photochemical cycloaddition reactions, and relates to a method for in-situ monitoring of the progress of a photochemical cycloaddition reaction by means of fluorescence spectroscopy. The method for in-situ monitoring of the progress of a photochemical cycloaddition reaction by means of fluorescence spectroscopy of the present invention comprises: preparing a fluorescent material that can be subjected to a photochemical cycloaddition reaction; causing the fluorescent material to be subjected to a photochemical cycloaddition reaction under the irradiation of ultraviolet visible light; monitoring a fluorescence change of the material by means of fluorescence spectroscopy; and performing in-situ monitoring on the photochemical cycloaddition reaction to monitor the reaction progress of the occurred photochemical reaction. Compared with conventional in-situ monitoring technology, the method for in-situ monitoring of the progress of a photochemical cycloaddition reaction by means of fluorescence spectroscopy has the advantages of being simple to operate, rapid and efficient, and easy to capture signals, having a wide range of application, and reducing the experimental costs and the operation difficulty.

The invention discloses a preparation method of a hydroxyl-functionalized quaternary phosphonium salt polyion liquid super-crosslinked heterogeneous catalyst and an application of the catalyst in catalysis of a cycloaddition reaction of CO2 and epoxide. Trimethoxytriphenylphosphine and dibromo-p-xylene are firstly subjected to quaternary phosphating to form triphenylphosphine-based ionic liquid, and then the triphenylphosphine-based ionic liquid and biphenyl benzyl dichloride can be subjected to aromatic electrophilic substitution reaction in the presence of 1, 2-dichloroethane serving as a solvent and anhydrous aluminum chloride serving as a Lewis acid catalyst to realize cross-linking, so that the triphenylphosphine-based ionic liquid can be prepared. And methoxy can be removed to form hydroxyl, so that the hydroxyl-functionalized quaternary phosphonium salt polyion liquid super-crosslinked polymer is prepared in one step. The resulting heterogeneous catalyst effectively converts CO2 to cyclic carbonates under milder conditions (80 DEG C, 1 atm) in the absence of a soluble co-catalyst.

The application belongs to the field of catalytic synthesis of fine chemical products, and particularly relates to an ionic compound and a method for catalytically synthesizing cyclic carbonate. The application provides an ionic compound, which comprises an anion as shown in formula (I) or formula (II); wherein X is selected from O, S and Se, and the value of L is 0 or 1; the anion in the ionic compound has suitable nucleophilicity and leaving property, can be combined with other active positive ions or metal ions to form a catalytic system with good solubility, and is particularly suitable for being used in a cycloaddition reaction involving carbon dioxide. Meanwhile, the application further provides a catalytic method for synthesizing cyclic carbonate, which uses a catalytic system containing the ionic compound, so that cyclic carbonate can be synthesized in a solvent-free, low-halogen or halogen-free, low-catalyst-amount and mild reaction condition mode with high efficiency, high conversion rate and high chemical selectivity.

The invention relates to the technical field of organic synthesis, in particular to a method for synthesizing cyclopentane compounds through [3 + 2] cycloaddition reaction of aryl cyclopropane and olefin under the synergistic catalysis of bromide ions / visible light. The method comprises the following steps: in a nitrogen atmosphere, sequentially adding aryl cyclopropane, a benzyl malononitrile derivative, pyridine tribromide and a photocatalyst into a reaction solvent to obtain a mixture, stirring the mixture at the temperature of 40 DEG C under the irradiation of a 12W blue light LED lamp until the reaction is complete, and performing concentration and column chromatography purification to obtain the cyclopentane compound. The method has the advantages of mild reaction conditions, simple operation, simple and easily available raw materials and low cost.

The application relates to the technical field of catalysts, and discloses a limited type iodine-based homogeneous immobilized catalyst as well as a preparation method and application thereof. The catalyst comprises a carrier and iodine ions, magnesium ions and quaternary ammonium ions loaded on the carrier, wherein the molar ratio of the magnesium ions, the quaternary ammonium ions, the iodine ions and the carrier is 0.01-1:4-15:1-30:1. The limited type iodine-based homogeneous immobilized catalyst disclosed by the application enhances the electrostatic interaction between iodine ions and quaternary ammonium ions through the molecular sieve limiting effect to construct a limited type structure. The catalyst has significantly enhanced CO2 adsorption and activation capacity, can activate an epoxide compound, and accelerates the ring opening of the epoxide compound. In a cycloaddition reaction catalyzed by the catalyst under the conditions of no solvent and no auxiliary agent, the conversion rate of propylene oxide can reach more than 73%, and the propylene carbonate selectivity can reach more than 85%.

The invention belongs to the technical field of catalytic synthesis, particularly relates to a method for preparing a nitrogen-containing fused ring compound through quantum dot catalyzed [4 + 2] cycloaddition, and aims to solve the problems of limited product structure and complex reaction system in the existing synthesis method. The synthesis method disclosed by the invention comprises the following steps: in an inert atmosphere, adding 1-phenylpyrrole and fumarate as reaction raw materials, quantum dots as a photocatalyst and an organic solvent into a reaction container, carrying out [4 + 2] cycloaddition reaction under visible light irradiation, and then filtering, concentrating, separating and purifying to obtain the nitrogen-containing fused ring compound. The reaction condition is mild, and the method can be realized by irradiating the quantum dot catalyst with a visible light source at normal temperature and pressure; a reaction system is simple, strong oxidants and additives are not needed, operation steps are convenient, and atom economy is achieved.