130results about How to "Catalytic reaction conditions are mild" patented technology

The invention belongs to the technical field of the chemical industry, which relates to a load type nano gold catalyst for preparing lactone by catalyzing air oxidation alpha, omega-diol. The invention adopts nano iron oxide as a carrier of a gold catalyst, the iron oxide is synthesized by a hydrothermal method, and nano iron oxide carriers with different crystal types and patterns can be preparedby calcination. The gold catalyst is prepared by a precipitation settling method, the prepared catalyst has small gold particles and good dispersivity, the interaction of gold and the carrier is strong, the gold catalyst represents an excellent activity in the preparation of gamma-butyrolactone by the direct oxidation of 1,4-butanediol through catalyzing air and the preparation of delta-valerolactone by oxidizing 1,5-pentanediol and conforms to the requirement of green chemistry, and the generation of lactone by oxidizing alpha, omega-diol in one step is realized. A magnetic iron oxide carrier can be obtained by selecting a proper preparation method, and the invention is convenient to separate and recover the catalyst and has better industrial application prospect.

The invention provides a method for one-step hydration synthesis of terpilenol by catalyzing turpentine through carbon-based solid acid. The method is characterized in that the turpentine is used as the raw material, isopropyl alcohol or butyl alcohol or isobutyl alcohol is used as the solvent, and the terpilenol is formed by means of one-step hydration synthesis through the turpentine under the catalytic action of a carbon-based solid acid catalyst. The carbon-based solid acid is prepared through a lignin gel method and has the advantages of developed micropores and mesopores, high catalytic activity, easy separation, good thermostability, repeatable utilization, easy regeneration, low preparation cost and the like; since the carbon-based solid acid is used for catalyzing the turpentine to form the terpilenol by means of one-step hydration synthesis, the conversion rate of the turpentine is up to 95-98 percent, and the yield of the terpilenol is 35-42 percent; besides, in the production process, no liquid waste acid or waste water is produced, pollution to the environment is greatly relieved, and the requirement for green chemistry is met.

The invention relates to a method for preparing isophorone, and belongs to the technical field of chemical material preparation. The method comprises the steps of: compounding the nitrate of metal magnesium, metal aluminum and metal zirconium into a mixed salt solution, dripping an aluminium nitrate solution and a zirconium nitrate solution into a magnesium nitrate solution at the same time under the condition of stirring, stirring for 1 to 1.5h, aging the obtained deposit for 0.5 to 1h under 50 to 60 DEG C, pumping, filtering and washing the deposit to be neutral, drying the deposit under 60 to 80 DEG C to obtain magnesium-aluminum-zirconium hydrotalcite samples, putting the hydrotalcite samples obtained by drying in a muffle furnace, calcining the hydrotalcite samples for 3 to 4h under 300 to 400 DEG C to prepare the needed catalyst, and cooling, grinding and sieving the catalyst. The hydrotalcite catalyst which is prepared in the method not only has high purity, good crystal form and the characteristic of hydrotalcite-like compounds but also has a porous structure, a large specific surface area and an alkaline site which are required for catalyzing the reaction; the catalytic reaction with mild condition and no pollution can be repeatedly used, thereby greatly lowering production cost.

A process for preparing high-performance TiSi zeolite by gas-solid method includes properly treating the B-contained molecular sieve for removing B from skeleton to obtain high-Si molecular sieve with a lot of hydroxy pits, and gas-solid reaction with TiCl4 to obtain TiSi molecular sieve with high catalytic oxidizing performance.

The invention specifically discloses a method for preparing cyclic carbonate from carbon dioxide and an epoxy compound through cycloaddition, which belongs to the technical field of organic synthesis. A difuran formaldehyde-1,2-phenylenediamine zinc complex is used as a catalyst in the method. Compared with the prior art, the invention has the following advantages: 1, furan formaldehyde (usually called as furfural) is prepared from corncobs or rice bran, so furan formaldehyde is cheap and is not a petrochemical product, and when furan formaldehyde is used to replace salicylaldehyde and diamine compounds for preparation of Schiff alkali ligand through a reaction, cost can be reduced and requirements of green chemistry are met; 2, the catalyst has the advantages of easily available raw materials, simple preparation, a stable structure, high catalytic efficiency and good selectivity; 3, when the catalyst provided by the invention is used for preparation of cyclic carbonate, catalytic reaction conditions are relatively mild and operation is easy; 4, no organic solvent is added in the reaction, and a product can be easily separated; and 5 5, the product and the catalyst can be easily separated, and the catalyst can be reused.

The invention relates to a method for preparing a diphenyl ketone compound. The method adopts a metal-supported oxide as a catalyst. The method comprises the specific process: after mixing a diphenyl methane compound, an oxidant, a solvent and the catalyst, refluxing at a normal pressure or putting into a reaction kettle for sealing, and stirring. The reaction temperature is higher than 50 DEG C, the reaction time is longer than 2 h, after the reaction, the catalyst is easily separated from the reaction system and can be recycled repeatedly, and the highest yield of the diphenyl ketone compound can reach 99%. The method for preparing the diphenyl ketone compound has the advantages of simple catalyst preparation, high stability, relatively mild reaction conditions, relatively high conversion rate of the diphenyl methane compound, and relatively high yield of the diphenyl ketone compound.

The invention discloses a method for directly synthesizing aniline from benzene and ammonia by one step, which takes benzene as a raw material, ammonia as an aminating agent, hydrogen peroxide as an oxidizer, acetonitrile as a solvent and TS-1 loaded by metal as a catalyst. The method for synthesizing aniline by one step has the characteristics of high yield of aniline, mild reaction condition, simple catalyst preparing process and easily obtained cheap raw materials, thus being a green synthesis method which has low cost and high yield and is simple and practicable.

The invention relates to the technical field of nanocatalysts, in particular to a catalyst for catalyzing hydrogenation reduction of nitrophenol and application thereof. The catalyst is an ultrathin bismuth oxychloride nanosheet with the diameter of 60-80nm, has very high catalytic activity in catalytic reduction of o-nitrophenol, m-nitrophenol and p-nitrophenol into corresponding aminophenol, and can replace a noble metal catalyst and be applied to a reaction of catalytically reducing the nitrophenol to prepare the aminophenol, so that the production cost is reduced.

The invention discloses an application of ionic liquid and a catalytic oxime removal method thereof, solving the problems of environment pollution and difficult product separation in an existing acid catalysis hydrolyzing and oxime removing method, and easily generated overreaction and lowered aldehyde ketone yield in an oxidation / reduction oxime removal method. The method comprises the followingsteps: 1) adding raw material oxime and ionic liquid serving as a deoximation catalyst in a reactor, stirring and refluxing at the temperature of 40-100 DEG C; and 2) adding extractant to recover theionic liquid serving as a deoximation catalyst, performing reduced pressure distillation on liquid at the extractant layer, removing the extractant to obtain the product after oxime removal. In the invention, the ionic liquid serves as a reaction catalyst as well as a solvent, has no volatility, and can be used repeatedly, needs no acidic reagent, and is an environment-friendly organic reaction solvent; the product is easily separated without byproducts, and the yield of aldehyde or ketone is 53.5-100%; and the ionic liquid can be used for protecting carbonyl groups or preparing aldehyde ketone compounds.

The invention provides a preparation method and application of a polyacid-based metal organic framework nanocrystalline catalyst. The nanocrystalline catalyst can be synthesized by a liquid-assisted grinding method, the obtained nanocrystalline catalyst has small particle dimension, and the grain size of the nanocrystalline catalyst is 50 to 200 nanometers; furthermore, the nanocrystalline catalyst has uniform morphology and size; meanwhile, the catalyst has determined component and structure. Under moderate condition, hydrogen peroxide is utilized as an oxidizing agent, the nanocrystalline can catalyze phenol to be degraded in high efficiency, and high phenol conversion rate and high mineralization rate are achieved. The catalyst can be completely separated and recycled through simple centrifugal operation, can be used repeatedly after being dried and can still keep good catalytic activity after being repeatedly utilized for multiple times. The preparation method of the polyacid-based metal organic framework nanocrystalline catalyst disclosed by the invention is simple and can effectively reduce the particle size of the catalyst; thus, phenomena of diffusional limitation and carbon deposit in catalytic reaction are reduced, and a material catalyzing efficiency is improved.

The invention discloses a making method of [Zn (C14H8O4) .H2O] as catalyst of aliphatic polycarbonate under indoor temperature, which is characterized by the following: copolymerizing carbon dioxide and epoxy cyclohexane at 60-100 deg. c under 2. 0-4. 5Mpa or reacting 2, 2'-diphenyl diformic acid and zinc acetate to produce the catalyst with molecular weight at 120, 000-160, 000 and Tg between 112 and 115; making the alternate copolymerizing rate more than 95% and catalyzing rate to 653 polymer / g zinc.

The invention relates to boron-resistant lysinibacillus boronitolerans ZJB-17007 and application thereof. The enantio-selectivity value for catalyzing N-phenylacetyl-DL-amino acid to produce L-amino acid reaches 99%, and the enantio-selectivity value for catalyzing 2-N-phenylacetyl-4-[hydroxy(methyl)phosphoryl]-DL-butyric acid to prepare 2-amino-4-[hydroxy(methyl)phosphoryl]-L-butyric acid reaches99%.

The invention relates to technology for synthesizing an intermediate in the medicinal and chemical industry, in particular to a catalyst for catalytic synthesis of N-methylpyrrolidine and a synthesis method thereof. The catalyst consists of a carrier and a catalytic activity component, wherein the carrier is a gamma-Al2O3 or HZSM series molecular sieve; the catalytic activity component is a simple substance of metal M or an oxide thereof; the catalytic activity component accounts for 0.5 to 20 percent of the total weight of the catalyst; and the granular size of the catalyst is 4 to 20 meshes. The catalyst is prepared by a kneading and extruding method or a dipping method. The catalyst has the advantages of simple preparation, low price of raw materials and easy purchase; and when used the catalytic synthesis of N-methylpyrrolidine, the catalyst has the advantages of mild catalytic reaction condition, low three-wastes and no pollution, wherein the conversion rate of tetrahydrofuran is substantially kept over 80 percent and the yield of the N-methylpyrrolidine is substantially kept over 60 percent.

The invention discloses a Nocardia sp. WY1202 and a production method for (R)-3-quinuclidinol through fermentation of quininone by using Nocardia sp. WY1202. According to the invention, quininone hydrochloride is used as a sole carbon source for the strain of Nocardia sp. WY1202 which is screened from soil in a farm orchard in Xiqing District, Tianjin City, China, and is preserved in China General Microbiological Collection Center with an accession number of CGMCC No. 5095. The production method comprises the following steps: with the Nocardia sp.WY1202 as a strain, carrying out primary seed culture and secondary fermentation amplification culture; taking a fermentation culture solution, collecting thalli through centrifugation, washing the thalli and re-suspending the thalli in a buffer solution; adding the substrate quininone hydrochloride, adding glucose and carrying out centrifugation after a reaction for 24 to 48 h; adjusting the pH value of a supernatant until the supernatant is alkaline; drying the supernatant through pressure reduced spinning; subjecting an obtained residue to solid-liquid extraction with an organic solvent; and drying an obtained filtrate through spinning so as to obtain (R)-(-)-3-quinuclidinol. According to the invention, the product (R)-(-)-3-quinuclidinol has a yield of 95%, a purity of 96% and an e.e value of more than 95%; the production method is simple to operate, has low energy consumption, accords with requirements for green chemistry and is applicable to large-scale bioconversion production for (R)-(-)-3-quinuclidinol.

The invention discloses a one-dimensional chain-like terbium (III) organic coordination polymer as well as a preparation method and application thereof. A compound takes 2,4-dichlorphenoxyacetic acid as a main ligand and 1,10-phenanthroline as an auxiliary ligand and has a one-dimensional chain-like structure; the preparation method of the compound comprises the following steps: taking the 2,4-dichlorphenoxyacetic acid, terbium salt and the 1,10-phenanthroline as raw materials and synthesizing through a solvent method; carrying out self-evaporation and crystallization to obtain a crystal. The organic coordination polymer emits relatively strong green fluorescence under the illumination of ultraviolet light, can be used as a light-emitting material and is widely applied to preparation of light emitting devices; meanwhile, the organic coordination polymer has a relatively good catalytic performance and has the advantages of high catalytic activity, moderate catalytic reaction conditions and the like in a process of synthesizing polyester by catalyzing binary acid and dihydric alcohol; the preparation method of the organic coordination polymer is simple to operate and has moderate reaction conditions; the obtained product has high yield and uniform crystal particles.

The present invention belongs to the field of chemical engineering and technology and is a method of using the loading nano-sized gold catalyst in the air for the direct oxidation of gamma-butyrolactone. The catalyst used in the present invention is prepared in a deposition and aggradation method. Specifically, the gold is deposited on the nano-sized titanium dioxide; the nano-sized Au / TiO2 catalyst can be got after roasting. The catalyst is good in dispersion, small in gold particles and good in stability, and can catalyze the air for the direct oxidation of 1, 4-butanediol to prepare the gamma-butyrolactone; the catalyst shows the excellent activity (the conversion rate of the 1, 4-butanediol is 100 percent; the collection rate of the gamma-butyrolactone is 99 percent). The present invention realizes the one-step oxidation of the 1, 4-butanediol to prepare the gamma-butyrolactone. In the oxidation process of the 1, 4-butanediol, the clean and easily accessible air is used as the oxidant to replace the strong oxidant in the traditional method such as the peracid, halogen oxide, nitrogen oxide and so on; the method avoids the production of the pollutants, and meets the requirements of the green chemistry. The catalyst can be repeatedly used and the relatively high activity can still be maintained; the method has the relatively high value for the industrial application.

The invention relates to a method for synthesizing 3-hydracrylic acid ester. The method mainly solves the problem that in the prior art, catalysts in a homogeneous system are difficult to separate. The method for synthesizing 3-hydracrylic acid ester includes the following steps that firstly, a ligand and cobalt carbonyl are subjected to a coordination reaction in an alcohol solvent to obtain turbid liquid of a catalyst; secondly, ethylene oxide and carbon monoxide are added, and a reaction is conducted to obtain 3-hydracrylic acid ester. According to the technical scheme, the ligand is selected from 4-vinylpyddine homopolymers or copolymers containing 4-vinylpyddine monomeric units, the technical problem is well solved, and the method can be used in industrial production of 3-hydracrylic acid ester.

The invention relates to a 1,2,3-triazole functionalized N-heterocyclic carbene binuclear nickel compound and a preparation method thereof and belongs to the field of organometallic chemistry. According to the 1,2,3-triazole functionalized N-heterocyclic carbene binuclear nickel compound, 1,2,3-triazole functionalized N-heterocyclic carbene is taken as a ligand, and the mole ratio of N-heterocyclic carbene to nickel is 1 to 1; the 1,2,3-triazole functionalized N-heterocyclic carbene binuclear nickel compound has a molecular structural formula shown in specification, wherein R1 is imidazole or benzimidazole, R2 is one of benzyl, n-butyl and phenyl, and X is either PF6 or BF4. The preparation method of the 1,2,3-triazole functionalized N-heterocyclic carbene binuclear nickel compound is simple, the binuclear nickel carbene compound is stable to air and moisture, and the distance among nickel atoms is relatively short, so that the compound has a metal-metal effect; by using the catalyst, cross-coupling reaction can be efficiently realized, and a variety of biphenyl derivatives can be obtained in the yield of being higher than 90%; the compound has very good functional group compatibility, is environment-friendly and can be extensively applied to fine chemical industry and pharmaceutical industry.

The invention relates to a catalyst for preparing propylene carbonate through the reaction of carbon dioxide and propylene oxide and the application thereof. The catalyst comprises a main catalyst ruthenium pyridine compound and an auxiliary catalyst quaternary. The molar ratio of the main catalyst to the auxiliary catalyst is 1:1 to 2, and the molar ratio of the main catalyst to the is 1:800 to 10000. The catalyst is used to catalyze the reaction of the carbon dioxide and the propylene oxide, so as to synthesize the propylene carbonate with high yield and high selectivity. The catalyst can be reused.

The invention discloses a method for preparing biodiesel by catalyzing waste oil with a caprolactam basic ionic liquid and belongs to the technical field of ionic liquid catalysis. According to the method for preparing the biodiesel by catalyzing waste oil with the caprolactam basic ionic liquid, the waste oil and alkyl alcohol are taken as raw materials, and the caprolactam basic ionic liquid is taken as a catalyst to prepare the biodiesel; and after reaction is finished, the ionic liquid and products are subjected to phase split automatically. The method for preparing the biodiesel by catalyzing waste oil with the caprolactam basic ionic liquid is simple in preparation process and low in cost. The method for preparing the biodiesel by catalyzing waste oil with the caprolactam basic ionic liquid has the advantages that firstly activity of the catalyst is high, and less catalyst is used; secondly, the catalyst is low in toxicity and can be easily biologically degraded; thirdly, reaction conditions are mild, and reaction time is short; and fourthly a reaction process is simple, products are easy to separate, no pollution is produced, and raw material utilization rate is high.

Provided is a method for catalyzing alcohol dehydrogenation silicon alkylation by using azacyclo-cabbeen. Catalyst azacyclo-cabbeen is dissolved in an organic solvent or directly placed in a schlenk tube (Schlenk tube) and a nuclear magnetism tube, silane and alcohol are sequentially added, a molar ratio of the silane to the alcohol is 1:1-2, a molar ratio of the catalyst azacyclo-cabbeen to the silane is 0.002-0.05:1, reaction is carried out at the normal temperature for 0.5-24h, then a solvent is extracted under a vacuum condition or distillation or column chromatography purification is directly carried out, and the alcohol dehydrogenation silicon alkylation can be carried out to prepare siloxane. The method has the advantages of using small organic molecule azacyclo-cabbeen to serve as a catalytic agent to replace a metal catalyst, is cheap in raw material, easy to prepare, soft in catalysis condition, high in catalytic activity, good in selectivity, easy in aftertreatment and wide in applicable scope of substrate silane, has good functional group tolerance, is single in reaction product, and can efficiently and selectively obtain the siloxane.

The invention discloses a dual-core cage-shaped earth samarium (III) organic complex, and a preparation method and application thereof. The complex adopts o-chlorobenzoic acid as a main ligand and 1,10-phenanthroline as an auxiliary ligand, and has a dual-core cage-shaped structure; the preparation method is characterized by adopting the o-chlorobenzoic acid, samarium salt and the 1,10-phenanthroline as raw materials, synthesizing through a solvent method, and obtaining an Sm2(C7H5OClCOO)6(C12H8N2)2 crystal through self-volatilization crystallization. The preparation method is simple to operate, moderate in reaction condition, high in product yield, and uniform in crystal particles; the earth samarium (III) organic complex is stable in structure, is used as a catalyst to be applied to catalyzing binary acid and polyhydric alcohols for carrying out esterification reaction to prepare an alkyd resin, and shows excellent catalytic activity.

The invention relates to a parachloronitrobenzene hydrogenation reduction catalyst capable of being magnetically recycled and a preparation method. Prepared Fe3O4 nanometer magnetic particles and water-soluble cobalt salt are added into water; ultrasonic full mixing is performed under the protection of inert gas, a reducing agent is added, and a target product is obtained after full reaction under ultrasound. Relevant salts such as iron and cobalt which are rich in nature are adopted as a matrix, raw materials are easy to obtain, and the cost is low. The prepared catalyst can be recycled through an external magnetic field due to the fact that the catalyst contains the Fe3O4 nanometer magnetic particles. The grain size of the prepared catalyst is 5-30 nm, so that the specific surface area can be 100-180 m<2> / g, and thus extremely huge promoting effects can be achieved on reagent adsorption and dispersion in the catalytic reaction process, and finally the conversion rate and selectivity reach 100%. The preparation method is simple, low in energy consumption, environmentally friendly and suitable for industrial production.

The invention discloses a rhodococcus (Rhodococcus sp.) bacterial strain ECU 1013, and the preservation serial number of the bacterial strain is CGMCC No.5911. The invention also discloses a preparation method of esterase of the rhodococcus and a method for catalyzing and preparing the (S)-(+)-2,2-dimethylcyclopropane carboxylic acid [(S)-(+)-DMPCA for short]. The rhodococcus bacterial strain ECU 1013 and the methods have the advantages that 2,2- dimethylcyclopropane carboxylic acid ester is catalyzed by using the rhodococcus and the esterase of the rhodococcus, enantioselective hydrolysis is performed and the (S)-(+)-DMPCA is prepared, the process has the advantages of being high in specifity, good in the catalyzing effect, mild in reaction condition, and the like. The optical purity of the target product (S)-(+)-DMPCA is 98% ee, and the single splitting is above 40%.

The invention provides a preparation method of polymethoxyl dimethyl ether by using lewis acid as catalyst. The preparation method of polymethoxyl dimethyl ether by using lewis acid as catalyst comprises steps of taking lewis acid as catalyst, trioxymethylene and dimethoxymethane as reaction raw materials, performing catalytic reaction and preparing polymethoxyl dimethyl ether. The invention further provides the polymethoxyl dimethyl ether prepared by the preparation method of polymethoxyl dimethyl ether by using lewis acid as catalyst. In the preparation method of polymethoxyl dimethyl ether by using lewis acid as catalyst, the catalyst can reduce the synthesis cost of the polymethoxyl dimethyl ether, improve the product distribution, promote product quality, remove corrosion, reduce the equipment maintenance cost, and keep environmental friendly; besides, the reutilization effect of the catalyst is excellent and obviously better than the other catalyst.

The invention relates to a K. intermedia ZJB-17004 and application thereof. The enantio-selectivity value of the K. intermedia for catalyzing N-phenylacetyl-DL-amino acid to produce L-amino acid reaches 98%, and the enantio-selectivity value of the K. intermedia for catalyzing 2-N-phenylacetyl-4-[hydroxy(methyl)phosphoryl]-DL-butyric acid to prepare 2-amino-4-[hydroxy(methyl)phosphoryl]-L-butyricacid reaches 99%.

The invention discloses a catalyst for preparation of aliphatic polycarbonate by reaction of carbon dioxide and cyclohexene oxide. The catalyst is a 2,6-bis(2-formyl phenoxymethyl)pyridine 2-amino-6-zinc picolinate coordination complex. The invention further discloses a method of adopting the catalyst for preparation of aliphatic polycarbonate by reaction of carbon dioxide and cyclohexene oxide. The mass of the catalyst is 0.1-1% of the mass of cyclohexene oxide, the reaction temperature of carbon dioxide and cyclohexene oxide in preparation of aliphatic polycarbonate is 60-150 DEG C, the carbon dioxide pressure intensity is 1-6MPa, the reaction time is 6-50h, and the whole copolymerization reaction of carbon dioxide and cyclohexene oxide in preparation of aliphatic polycarbonate is carried out under a solvent-free condition. The catalyst applied to copolymerization of carbon dioxide and cyclohexene oxide has advantages of high catalysis efficiency, high reaction selectivity, mild catalytic reaction condition and convenience in operation.

The invention relates to a preparation method of 3-hydroxy-propionaldehyde. The preparation method mainly solves the problem that a homogeneous system catalyst is difficult to recycle in the prior art. The preparation method of the 3-hydroxy-propionaldehyde comprises the following steps: a) performing a complexing reaction in a solvent on ligand and cobalt carbonyl so as to obtain a catalyst solution; and b) adding oxacyclopropane and synthesis gas, and reacting to obtain the 3-hydroxy-propionaldehyde, wherein the ligand is of a following structure, X is selected form one of an oxygen atom and a sulfur atom, and R is selected from one of a cyclo group, an aryl group or a substituted aryl group. Through the technical scheme, the technical problem is preferably solved, and the preparation method can be used in industrial production of the 3-hydroxy-propionaldehyde.

The invention discloses a mesoporous silicon dioxide-loaded metal phthalocyanine catalyst and a preparation method thereof. The preparation method comprises the following steps of: in the preparation process, using a certain amount of tetra alkyl silicate and emulsifying agent to prepare an ethyl alcohol solution, gradually adding into a deionized water solution containing a certain amount of the template agent and the emulsifying agent, and stirring for 2h at room temperature; transferring into a reaction kettle, crystallizing for a period of time, cooling to room temperature, filtering and washing, drying, and calcining at high temperature, so as to obtain metal ion-modified mesoporous silicon dioxide microspheres; (2) mixing the mesoporous silicon dioxide microspheres, the catalyst, phthalic anhydride, ammonium chloride and urea according to a certain ratio, putting into a reaction kettle containing an organic solvent, heating to reach the reflux conditions, stirring and reacting for 2h, sucking and filtering, washing until the filtrate is in a neutral state, and drying, so as to obtain the mesoporous silicon dioxide-loaded metal phthalocyanine. The mesoporous silicon dioxide-loaded metal phthalocyanine catalyst is characterized in that the types of metal ions are rich, the content is high, the selectivity on catalyzing primer is high, the catalyzing speed is high, and the reaction condition is mild.

The invention acquires the glycosyltransferase mutants SEQ ID NOs:3-6 with enhanced enzyme activity by directed evolution method. The mutants or expressing microorganisms thereof can efficiently catalyze the glycosyl transfer reaction of protopanaxadiol to prepare ginsenoside CK, and have industrial development and application prospects.