263 results about "Nucleophile" patented technology

The invention discloses a preparation method of a biomass-derived sunken hollow porous carbon sphere material. The preparation method comprises the following steps: (1) preparing a cellulose solution from a biomass material; (2) metal salt and an amine nucleophilic reagent are coordinated and then added into the cellulose solution for self-assembly, and a solution with a hollow structure is obtained; (3) applying an external electric field to the solution containing the hollow structure, stirring and soaking with a buffer solution, performing solid-liquid separation, and drying a solid phase to obtain a sunken hollow sphere structure; and (4) carrying out calcination treatment on the concave hollow sphere structure, and then carrying out acid pickling to obtain the biomass derived concave hollow porous carbon sphere material. The invention also provides a biomass-derived sunken hollow porous carbon sphere material and a lithium ion battery. According to the preparation method of the biomass-derived sunken hollow porous carbon sphere material, the obtained sunken hollow porous carbon sphere material has relatively large specific surface area, high microporosity and good conductivity.

The invention provides a halohydrin dehalogenase mutant and an application of the halohydrin dehalogenase mutant in synthesis of a chiral gamma-amino alcohol compound. Halogenated alcohol dehalogenase mutants enabling 2-substituted oxetane to be subjected to ring opening are obtained through the technologies of gene mining, directed evolution and the like, and the enzymes can directly perform ring opening on a substrate 2-aryl oxetane under the action of a nucleophilic reagent to generate a series of chiral gamma-amino alcohol compounds which are important precursors for synthesizing drugs. Therefore, the halohydrin dehalogenase mutants have important application value in the industry.

The invention relates to a nitrogen-containing heterocyclic compound as well as a preparation method and application thereof, belongs to the technical field of heterocyclic compound synthesis, and solves the problems of low reaction efficiency and high energy consumption caused by the fact that an existing method for synthesizing an indole maleimide derivative needs to be carried out step by step. The preparation method comprises the following steps: step 1, adding indoleacetamide and a nucleophilic reagent into a mixed solution, and reacting; 2, performing post-treatment to obtain a nitrogen-containing heterocyclic compound; the mixed solution comprises alkali, an additive and an organic solvent; the alkali comprises one of triethylamine (Et3N), N, N-diisopropylethylamine, pyridine and 1, 8-diazabicyclo [5.4. 0] undec-7-ene, and the alkali comprises one of 1, 8-diazabicyclo [5.4. 0] undec-7-ene.

The invention discloses a dechlorination regeneration method of a chlorine poisoning noble metal catalyst and an application of the regenerated noble metal catalyst in polyolefin hydrogenolysis, and the dechlorination regeneration method comprises the following steps: dispersing the chlorine poisoning noble metal catalyst in water, adding a strong nucleophilic reagent for treatment, and carrying out centrifugal separation, washing and drying treatment to obtain the chlorine poisoning noble metal catalyst. The regenerated noble metal catalyst is obtained. A strong nucleophilic reagent dechlorination regeneration strategy under a room temperature mild condition is provided, chemically inert metal-chlorine bonds are broken through a nucleophilic substitution effect, noble metal particles are prevented from being agglomerated and sintered while deep dechlorination is realized, polyolefin hydrogenolysis activity of the catalyst can be completely recovered, activity improvement can be realized, and the catalyst has a good application prospect. Meanwhile, the regeneration cost is greatly reduced, and the regenerated noble metal catalyst can be used for efficiently hydrogenolyzing, upgrading and recycling waste polyolefin to obtain liquid alkane fuel with high additional value.

The invention discloses a full-bio-based adhesive based on epoxidized soybean oil and a preparation method of the full-bio-based adhesive. Specifically, according to the method, epoxidized soybean oil is taken as a reaction substrate, citric acid is taken as a nucleophilic reagent to open an epoxy ring of the epoxidized soybean oil, tannic acid is taken as a catechol-like compound to provide adhesion performance after cross-linking polymerization, and a bio-based cross-linked network structure with excellent adhesion performance is constructed. The environment-friendly adhesive is researched and developed on the basis of full bio-based raw materials, and has the remarkable characteristics of no toxicity, reproducibility, environment friendliness and the like. The adhesive adopts an efficient one-pot synthesis process, the preparation process is simple and convenient, and industrial mass production is easy to realize. And the performance is excellent, the tensile strength and long-term stability are excellent, and due to the outstanding water resistance and mildew-proof performance, the coating stands out of similar products. In addition, the product is wide in raw material source and obvious in cost advantage, and has high performance and economic benefits.

The invention discloses a bio-based epoxy resin composite material and a preparation method thereof. The bio-based epoxy resin composite material is prepared from the following raw materials in parts by weight: 20 to 35 parts of epoxidized soybean oil, 25 to 37 parts of modified cellulose, 15 to 25 parts of polybasic organic acid, 10 to 23 parts of nucleophilic reagent, 5 to 8 parts of polyhydric alcohol and 0.1 to 1 part of curing accelerator, the modified cellulose is modified cellulose with carboxyl on the surface; the nucleophilic reagent is an aryl-containing nucleophilic reagent and contains at least two nucleophilic groups, and the nucleophilic groups are hydroxyl and / or carboxyl. The bio-based epoxy resin composite material disclosed by the invention has good mechanical strength and relatively high tensile strength, Young modulus and glass transition temperature.

The invention provides a bissanthin aromatic ring bay region C-H nucleophilic substitution reaction method and application thereof, and belongs to the field of organic synthesis methodology. According to the reaction, bissanthin is used as a raw material, dichloromethane and acetonitrile are used as solvents, and the bissanthin is oxidized by nitrite hexafluorotellurate and respectively reacts with nucleophilic reagents such as carbon anions, oxygen-containing reagents, sulfur-containing reagents, chlorine-containing reagents, nitrogen-containing reagents, phosphorus-containing reagents and cyano groups in one step to synthesize a series of bissanthin bay area modified functionalized products; when the reaction method is further applied to the nucleophilic substitution reaction of two molecules, namely perylene (Perylene) and N, N '-di (1, 3-diisopropyl benzene)-3, 4, 9, 10-perylene dicarboximide (PDI), good universality is shown, and the reaction method can be applied to the nucleophilic substitution reaction of two molecules, namely perylene (Perylene) and N, N'-di (1, 3-diisopropyl benzene)-3, 4, 9, 10-perylene dicarboximide (PDI). The method is mild in reaction condition, does not need to introduce transition metal as a catalyst, is easy in product separation and purification, and has the advantages of low cost, high efficiency and greenness; the series of functionalized derivatives constructed by the method can provide important intermediates for synthesis of larger polycyclic aromatic hydrocarbon molecules of the system; the method has a good industrial production prospect.

High molecular weight functionalized polymers (“high dielectric polymers”) are disclosed herein, along with related methods of use and manufacture. The high dielectric polymers have a relatively high dielectric permittivity (e.g., greater than 10) as well as a relatively low glass transition temperature (e.g., less than −30° C.). The polymers may be produced utilizing addition polymerization or anionic ring opening to yield a linear or branched polymer backbone containing numerous residual nucleophiles. Then, nucleophilic substitution may be carried out to functionalize the residual nucleophiles. The functionalized polymer may then be purified and used as polymer electrolyte in an electrochemical cell (e.g., as nonaqueous polymeric electrolyte in a secondary Li-ion battery), if desired.

This invention belongs to the field of chemical synthesis and relates to a method for achieving deuterated methylation of a nucleophile. The invention provides a deuterated methylating reagent, which is obtained by reacting formic acid with deuterated methanol under acidic conditions, followed by a second reaction with thiaanthracite and trifluoromethanesulfonic acid. The nucleophile is then reacted with the deuterated methylating reagent described in claim 1, a base, and a solvent to obtain the deuterated methylated product. This invention also provides a method for achieving deuterated methylation of a nucleophile, which involves dissolving the nucleophile and 5-deuterated methyl-5H-thiophene-5-onium trifluoromethanesulfonate in a suitable solvent, adding a base, and then performing the deuterated methylation reaction at room temperature. In the method provided by this invention, the yield of the product after nucleophile methylation can reach 52% to 95%.

The invention relates to the technical field of organic dyes, in particular to a novel xanthene dye for blue photoresist color paste and a synthesis method of the novel xanthene dye. The invention relates to a synthesis method of a novel xanthene dye for blue photoresist color paste, which comprises the following steps: 1) taking rigid cyclic amine as a nucleophilic reagent, and carrying out aromatic nucleophilic substitution reaction on a chlorinated xanthene compound to obtain a xanthene intermediate; 2) performing chlorination reaction on the xanthene intermediate by using a chlorination reagent to obtain a chlorinated xanthene intermediate; 3) mixing active amine and the chlorinated xanthene intermediate, and performing substitution reaction under the action of alkali to obtain the novel xanthene dye for the blue photoresist color paste.The novel xanthene dye for the blue photoresist color paste.The novel xanthene dye for the blue photoresist color paste.The novel xanthene dye for the blue photoresist color paste.The novel xanthene dye for the blue photoresist color paste has the advantages of being high in solubility, good in thermal stability and high in contrast ratio.

Partially oxidized carbonaceous materials characterized by substantially homogenous, partially oxygenated surfaces thereof are enabled via microwave-assisted methods that are simple and fast. The exemplary methods include combining carbonaceous material(s), at least one mild oxidizer, at least one nucleophile, and an aqueous solvent system to obtain a mixture; and exposing the mixture to microwave radiation for a predetermined time to produce partially oxidized carbonaceous materials. The predetermined time may be in a range from about 5 seconds to about 2 hours, and the power of the microwave energy may be in a range from about 100 w to about 1700 W. The partially oxidized carbonaceous materials are characterized by a homogeneous distribution of oxygen content in surfaces thereof, in nonzero amounts up to about 10 at %, and a standard deviation of surface oxygen content in a range from about 0.1 at % to about 1.0 at %.

The invention relates to a gel electrolyte and a preparation method and application thereof. The gel electrolyte is prepared from the following raw materials: a nitrogen heterocyclic gel monomer, an electrolyte and an initiator, the nitrogen heterocyclic gel monomer is prepared from the following raw materials: a nucleophilic reagent and an epoxy compound. The gel electrolyte provided by the invention is high in conductivity and good in uniformity, can realize stable circulation under 5C multiplying power, and can be well applied to a quick-charge type gel battery.

The invention discloses a method for promoting degradation of penicillin antibiotics in a water body. The method comprises the following steps: S1, detecting water quality; s2, medium adjustment; s3, carrying out catalytic degradation; s4, precipitation reaction; medium adjustment is performed on the water body to be treated by using calcium ions and organic matters, so that an example state in the water body to be treated is good, the calcium ions can be coordinated with carbonyl and carboxyl in penicillin molecules, a hydrolyzed reaction intermediate is stabilized, the hydrolysis rate of penicillin antibiotics is increased, and the yield of penicillin antibiotics is increased. The characteristic functional groups such as amino and sulfydryl in the biological metabolism organic matter can also serve as strong nucleophilic reagents to promote rapid hydrolysis of penicillin antibiotics, and meanwhile, through specific setting of the method, it can be avoided that calcium ions and biological organic metabolism media cause secondary pollution to the to-be-treated water body before degradation.

Disclosed is a method for producing an iodine-containing tertiary alcohol ester, the method including: a nucleophilic step for reacting an iodine-containing compound represented by formula (1) with a nucleophilic agent; and an acylation step for adding an acylating agent to the reaction liquid obtained in the nucleophilic step so as to obtain an iodine-containing tertiary alcohol ester. The nucleophilic step and the acylation step are continuously performed without having an isolation step after the nucleophilic step.

The invention discloses a trifluoromethyl-containing polysubstituted phosphorus-doped six-membered ring phosphine oxide compound as well as a preparation method and application of the trifluoromethyl-containing polysubstituted phosphorus-doped six-membered ring phosphine oxide compound. A diene-containing three-stage phosphine oxide compound is used as a raw material, a trifluoromethyl reagent and a nucleophilic reagent are used, in the presence of a transition metal copper catalyst and a pyridine-oxazoline ligand, a free radical domino cyclization reaction is initiated to obtain the compound, C-O, C-N and C-C coupling is realized, and the variety of the nucleophilic reagent can be changed, so that the structure of the product is diversified. The diastereoisomers can be separated, the yield of a single diastereomer can reach 85%, and the diastereoisomers have excellent diastereoselectivity. The invention provides a novel reaction mode of constructing a polysubstituted phosphorus-doped six-membered ring by mediation of free radicals, the reaction condition is mild, the operation is simple, the substrate universality is good, a novel skeleton structure of an organic phosphine reagent is provided, and the variety diversity of the organic phosphine reagent is expanded. The synthesized compound can be used as a catalyst to be applied to Appel reaction, and has a good application prospect.

The invention relates to a self-immobilized hydrogen peroxide imaging tracer agent as well as a preparation method and application thereof, and belongs to the technical field of nuclear medicine. The invention provides a series of self-fixing type hydrogen peroxide imaging tracers based on aryl boric acid ester. The tracers comprise [18F] HYAS, [18F] HYAT and the like. The series of tracers are high in self-fixing capacity and can react with H2O2 to form QM intermediates, so that the QM intermediates and nucleophilic reagents in biomacromolecules form covalent bonds; in addition, the series of tracers have the physicochemical property of being capable of penetrating through the blood brain barrier; meanwhile, experiments show that the series of tracers can distinguish tissues with different H2O2 concentrations in vivo, and in animal brains treated by 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine, ingestion increase of the series of tracers can be observed, and the series of tracers have very strong H2O2 responsiveness. In conclusion, the series of tracers have great application prospects in non-invasive imaging of H2O2 in the brain.

The present invention provides a microcapsule composition comprising at least one core-shell microcapsule, wherein the at least one core-shell microcapsule comprises a core comprising at least one benefit agent and a shell surrounding the core, wherein the shell comprises a resin formed by the reaction of: 5 - a Michael acceptor which is the reaction product of a biodegradable polyester polyol with an α,β-unsaturated acid chloride; and - a Michael donor comprising at least two nucleophilic moieties selected from the group consisting of a nitrogen nucleophile, a sulfur nucleophile, an oxygen nucleophile, a carbon nucleophile, a phosphorus nucleophile, and mixtures thereof, which are capable to react with the 10 acrylic double bond of the Michael acceptor. The invention also relates to consumer products comprising the microcapsule composition, a method for preparing the microcapsule composition and to the use of the microcapsule composition to enhance the performance of a benefit agent in a consumer product.

The invention discloses a method for synthesizing a sulfur-containing compound by using an amino sulfur trifluoride compound, which comprises the following two steps: S1, by taking the amino sulfur trifluoride compound and a compound A as reactants, stirring and reacting for 8-15 minutes or 10-15 hours at normal temperature in an organic solvent under an alkaline condition; the compound A is any one of an amide compound or a sulfanilamide compound, or water; and S2, adding a nucleophilic reagent into the solution after the reaction in the step S1, stirring at normal temperature to react for 8-15 minutes or 5-8 hours, and then purifying through a rapid chromatography to obtain a final product, namely, all-heteroatom substituted thioimine or all-heteroatom substituted sulfoxide, the nucleophilic reagent is an alcohol or an amine. According to the method disclosed by the invention, the amido sulfur trifluoride compound is used for synthesizing the asymmetric full heteroatom substituted thioimine and sulfoxide compound for the first time, the reaction steps are simple, the reaction conditions are mild, and expensive reagents are not needed.

The present disclosure provides methods for preparing oligonucleotides. In certain embodiments, the present disclosure provides methods for preparing oligonucleotides using cyclic-phosphate or cyclic-thiophosphate nucleosides. In certain embodiments, the present disclosure provides methods for preparing oligonucleotides using nucleophiles selected from substituted thiol nucleophiles, substituted nitrogen-based nucleophiles, substituted phosphine nucleophiles, halides, pseudohalides, azides, and substituted lithium-based nucleophiles.

The invention relates to the technical field of chemical synthesis, and discloses a preparation method and control of an abelsiril impurity A, namely 6-(4-chloro-5-fluoropyrimidine-2-yl)-4-fluoro-1-isopropyl-2-methyl-1H-benzimidazole. The preparation method comprises the following steps: S1, carrying out aromatic nucleus nucleophilic substitution reaction on a compound I and a nucleophilic reagent in an organic reagent, washing an organic phase, drying, filtering, and drying to obtain a compound II; concentrating under reduced pressure to obtain a compound II; s2, mixing the compound II, the compound III, a palladium catalyst, alkali and an organic solvent, performing heating reflux under the protection of nitrogen, performing Suzuki coupling reaction, performing vacuum concentration, and washing a filter cake with tetrahydrofuran to obtain a compound IV; s3, carrying out demethylation reaction on the compound IV to obtain a compound V; s4, the compound V reacts with a chlorination reagent, reduced pressure distillation is conducted, separation and purification are conducted, and the abelsilib impurity A is obtained. The design route provided by the invention is reasonable, the reaction site selectivity is good, and the impurity A with relatively high purity can be obtained.

The invention provides an olefin hydrocarbonylation method which comprises the following step: olefin as shown in a formula (1), a nucleophilic reagent as shown in a formula (2) and carbon monoxide are subjected to a hydrocarbonylation reaction under the action of a metal catalyst, a ligand, protonic acid and optional iodide under the condition of illumination. According to the present invention, olefin represented by a formula (1), a nucleophilic reagent represented by a formula (2) and carbon monoxide are adopted as raw materials, and under the action of a metal catalyst, a ligand, a protonic acid and an optional iodide, a hydrocarbonylation reaction is performed under the illumination condition so as to obtain carboxylic acid / ester / amide / thioester and other products; the method provided by the invention can be realized at normal temperature and normal pressure, does not need special equipment, has low potential safety hazard and low energy consumption, greatly reduces the cost of large-scale production of carboxylic acid / ester / amide / thioester, and provides a novel green and efficient synthesis process for industrial production of carboxylic acid / ester / amide / thioester.

The invention discloses a method for co-catalyzing intramolecular cyclization of cis-epoxide by diarylboronic acid and tetrabutylammonium halide, and belongs to the technical field of organic synthesis. According to the method, diarylboronic acid and tetrabutyl ammonium halide are used as catalysts, and the bicyclol is synthesized through intramolecular ring closing reaction of cis-4-hydroxymethyl-1, 2-cyclopentene oxide in an organic solvent; according to the method, a cis-substrate is activated by diarylboronic acid, tetrabutylammonium halide is used as an instantaneous nucleophilic reagent to enable epoxy to be subjected to ring opening, oxygen in the substrate is subjected to intramolecular nucleophilic attack, and then halide ions are removed, so that an intramolecular ring closing product is obtained, and the reaction shows good functional group tolerance. The method has the characteristics of low catalyst dosage (one thousandth), simplicity and convenience in operation, high yield, environment friendliness and mild reaction conditions, and has potential practical application value.

The application belongs to the field of organic synthesis, and discloses a method for preparing chiral 2-(1,3-diarylallyl)malonate by using a Pd / phosphine oxygen bidentate phosphine phenol ligand catalysis, which comprises the following steps: under a protective atmosphere, mixing P, O-bidentate phosphine phenol ligand, a palladium catalyst, N, O-bis(trimethylsilyl)acetamide, a malonate nucleophilic reagent and an allyl acetate electrophilic reagent in dichloromethane, and reacting to obtain chiral 2-(1,3-diarylallyl)malonate product. The system has the advantages of high enantioselectivity, high catalytic efficiency, wide substrate application range and mild conditions.

The application discloses a kind of full biological base adhesive based on epoxy soybean oil and preparation method thereof.Specifically, the method uses epoxy soybean oil as reaction base, citric acid as nucleophilic reagent to open the epoxy ring of epoxy soybean oil, tannic acid as catechol compound to provide adhesion after crosslinking polymerization, and constructs a biological base crosslinking network structure with excellent bonding performance. The present application is an environmentally friendly adhesive developed based on full biological base raw materials, with the outstanding features of non-toxic, renewable and environmentally friendly. The adhesive uses a one-pot synthesis process, which is simple and easy to implement industrial production. In terms of performance, it performs outstandingly, not only has excellent tensile strength and long-term stability, but also has outstanding water resistance and mildew resistance, making it stand out among similar products. In addition, the product has a wide range of raw materials, obvious cost advantage, and high performance and economic benefit.

The present invention discloses a preparation method and application of a compound based on a benzimidazole-1-ylmethanol core, wherein the compound comprises reacting (1H-benzimidazole-1-yl)methanol with a nucleophilic reagent R-XH to prepare the compound. The present invention uses cheap raw materials and simple synthesis steps, which not only achieves a significant reduction in cost, but also ensures a higher yield, thereby laying a solid foundation for the large-scale production of benzimidazole-1-ylmethanol core compounds. At the same time, the present invention ensures the quality and stability of the final product by accurately controlling the reaction conditions and optimizing the operating process. The compound of the present invention can prevent metal from being corroded in an alkaline environment and the pH value of the test solution does not decrease significantly. The present invention can select suitable chemical reagents and chemicals to modify and replace the compound based on "benzimidazole-1-ylmethanol" as the core according to different needs to meet different needs.

This invention relates to a waterproof coating for walls and its preparation method, belonging to the field of coating technology. The waterproof coating of this invention is prepared from the following components: 50-53 parts by weight of epoxy resin, 75-81 parts by weight of curing agent, and 8.5-11.5 parts by weight of waterproof filler. The waterproof filler is prepared by the following steps: reaction of epoxidized nano-silica with the nucleophilic reagent p-aminophenyl POSS, ring-opening and polymerization of N-acid anhydride, and modification with ethyl isocyanate. This invention uses epoxy resin as the film-forming substance and constructs a waterproof system by adding waterproof filler to prepare a waterproof coating suitable for application on walls. It can achieve a relatively ideal waterproof effect without the need for additives, effectively blocking the intrusion of water, and the coating has a low water absorption rate.

A use of a compound of formula Y: (Y) to form a protected nucleophile, wherein a single substituent selected from R1-R4 is -CH2-LG or -CH2-OH, wherein LG is a leaving group; at least one substituent s

The invention relates to a multi-metal zinc complex, a preparation method and application in polymer depolymerization. The multi-metal zinc complex forms a stable coordinate bond with an organic ligand molecular skeleton, shows excellent chemical stability and substrate adaptability, and can efficiently catalyze the depolymerization reaction of various polymers in a temperature range of 100-250 DEG C. In addition, the ligand framework has adjustability, polymer substrates with different compositions and structures can be optimized, and high-yield recovery of various types of monomers is realized. The catalytic system has wide applicability, can catalyze the bulk depolymerization of the polymer, and also can catalyze the depolymerization in the presence of a nucleophilic reagent. Through a multi-metal concerted catalysis mechanism, the dosage of the catalyst is remarkably reduced, various polymers with the number-average molecular weight in the range of 3.8-807.5 kg / mol can be depolymerized, the depolymerization reaction time is 0.5-24.0 h, side reactions are remarkably inhibited, and excellent industrial application prospects are shown.

The invention relates to cyclotrithio-tri (2-mercaptoethylthio) mercaptan as shown in a formula I and a preparation method and application thereof. A two-step method of thio reaction and nucleophilic substitution is adopted. In the step I, thiourea is used as a sulfur source, epoxy atoms in trioxymethylene are replaced by sulfur atoms one by one under the condition of strong acid, and 1, 3, 5-trithiacyclohexane is generated. In the nucleophilic reaction of acid catalytic activation in the step II, 1, 3, 5-trithioxane and Lewis acid are subjected to coordination complexation firstly, one sulfydryl in dithiol serves as a nucleophilic reagent to attack an electrophilic carbon center of a ring-opening intermediate, a new C-S bond is formed, and a linear intermediate containing sulfydryl is generated; according to the process, three thiol groups are introduced in sequence step by step, and sulfur alkylation substitution is completed. The obtained product has the characteristics of high purity, high light transmittance and large refractive index, and can be used for preparing optical materials with ultrahigh refractive index and high light transmittance.

The invention discloses DNA (deoxyribonucleic acid) coupled non-natural amino acid as well as a synthesis method and application thereof. The synthesis method of the DNA coupled non-natural amino acid comprises the following steps: adding inorganic alkali and 2, 5-dibromohexane diamide into a boric acid buffer solution containing DNA coupled cysteine as shown in a general formula (I) in the specification, adding an organic phase, and reacting at 25-37 DEG C to enable the DNA coupled cysteine to be subjected to desulfurization elimination, thereby obtaining the DNA coupled non-natural amino acid. DNA coupling dehydroalanine shown as a general formula (II) in the specification is obtained; the method comprises the following steps: carrying out nucleophilic addition reaction on DNA coupled dehydroalanine and a nucleophilic reagent under an alkaline condition or carrying out dipolar cycloaddition reaction on DNA coupled dehydroalanine and 2, 5-substituted tetrazole under an ultraviolet condition to obtain the DNA coupled unnatural amino acid. By adopting the method, the integrity of the DNA chain can be effectively ensured, no by-product is generated in the reaction, and a more powerful chemical tool is provided for construction and subsequent modification of a DNA coding molecular library.