一种高效简易的聚(4-乙烯基三溴化吡啶)催化乙醇合成乙酸盐的方法(英文)

Poly(4-vinylpyridinium tribromide) is an efficient catalyst for the conversion of various alcohols to their corresponding acetate derivatives with acetic anhydride.This method has some advantages such as mild reaction conditions,good to excellent yields,and ease of work-up.

三溴化聚乙烯吡咯烷酮高效催化醇和酚的乙酰化反应(英文)

An efficient and versatile procedure for the acetylation of alcohols and phenols using acetic anhydride in the presence of a catalytic amount of polyvinylpolypyrrolidoniume tribromide has been successfully developed.Primary,secondary,and tertiary alcohols,as well as a selection of the phenolic compounds,have been successfully acetylated according to this procedure,with good to high yields being achieved over short reaction times.

1,1,1,3,3,3-六甲基二硅氮烷与PhMe_3N^+Br_3~–选择性催化醇与酚的三甲基硅烷化反应(英文)

An efficient procedure for the trimethylsilylation of alcohols and phenols is presented.The combination of 1,1,1,3,3,3-hexamethyldisilazane and a catalytic amount of phenyltrimethylammonium tribromide(PhMe3N+Br3?) was found to be effective for the trimethylsilylation of alcohols and phenols.The protection reaction is very simple and homogenously performed in dichloromethane at room temperature and mild conditions.

Synthesis and characterization of a Pd(0) Schiff base complex anchored on magnetic nanoporous MCM-41 as a novel and recyclable catalyst for the Suzuki and Heck reactions under green conditions

A Pd Schiff base complex was immobilized onto the surface of magnetic MCM‐41(Fe3O4@MCM‐41@Pd(0)‐P2C)as a novel,eco‐friendly,and recyclable heterogeneous nanocatalyst and fully characterized by FT‐IR,VSM,EDS,transmission electron microscopy,scanning electron microscopy,thermogravimetric analyses,ICP‐OES,and X‐ray powder diffraction analysis.The Fe3O4@MCM‐41@Pd(0)‐P2C was investigated as a catalyst for the one‐pot Suzuki and Heck reactions in PEG as a green solvent to provide the target products in excellent yields.The main advantages of using this catalyst include a short reaction time,green reaction conditions,a simple experimental procedure,non‐use of hazardous organic solvents,low loading of the catalyst,and the ability to use various substrates.More importantly,the catalyst could be easily separated from the reaction mixture with the assistance of an external magnet and could be recovered and reused several times without significant loss of stability and activity.

无溶剂条件下三聚氰胺-Br_3催化一锅法合成1-氨基烷基-2-萘酚(英文)

A facile and efficient method has been developed for the synthesis of 1-amidoalkyl-2-naphthols via the one-pot multi-component condensation of 2-naphthol with aromatic aldehydes and acetamide or thioacetamide in the presence of melamine-Br3 under solvent-free conditions. There are several advantages to this reaction, including high yields, short reaction time, and high catalytic efficiency.

天门冬氨酸催化1,1,1,3,3,3-六甲基二硅氮烷硅烷化羟基为三甲基硅醚(英文)

A wide variety of alcohols and phenols were protected as trimethylsilyl ethers using 1,1,1,3,3,3-hexamethyl disilazane catalyzed by aspartic acid as a non-toxic,metal-free,and green organocatalyst at room temperature in acetonitrile under mild and heterogeneous conditions.The procedure is operationally simple and the silylated product was obtained in high yield and purity.

溴化钾催化硫化物、硝酸铵和SiO_2-OSO_3H固体酸的氧化反应(英文)

A convenient and selective catalytic method for the sulfoxidation of aliphatic and aromatic sulfides by treatment of NH4NO3, silica sulfuric acid, wet SiO2 (50% w/w) and a catalytic amount of KBr in CH2Cl2 at room temperature was developed. Many sulfides can be selec-tively oxidized at room temperature in good to excellent yields. The reaction proceeds without over-oxidation to sulfones under mild conditions.

A novel catalytic method for the regeneration of carbonyl compounds from oximes using aluminum nitrate and NaBr as catalyst

A wide variety of aldoximes and ketoximes were regenerated to corresponding carbonyl compounds with Al（NO3）3·9H2O in presence of catalytic amounts of NaBr in CH2Cl2 at room temperature.

新型多功能三溴三聚氰胺催化剂催化醇甲酰化和乙酰化反应(英文)

Tribromo melamine has been found to be an efficient and green organocatalyst for the acetylation and formylation reactions of alcohols with acetic anhydride and ethyl formate at room temperature and under mild reaction conditions.

Synthesis of biaryls using palladium nanoparticles immobilized on peptide nanofibers as catalyst and hydroxybenzotriazole as novel phenylating reagent

Peptide nanofibers decorated with palladium nanoparticles catalyzed direct coupling of aryl halides with hydroxybenzotriazole to afford the corresponding biaryls in good to excellent yields.The coupling reactions proceeded under simple,green,and mild conditions.The peptide nanofibers were used as recyclable supports in the coupling reactions.This approach is the first to use hydroxybenzotriazole as a phenylating agent.

聚(4-乙烯基吡啶硝酸盐)、硅硫酸和溴化铵催化氧化硫化物生成亚砜(英文)

A new catalytic procedure for the chemoselective oxidation of sulfides to sulfoxides was studied.A variety of aliphatic and aromatic sulfides were subjected to sulfoxidation by combining poly(4-vinyl pyridinium nitrate),silica sulfuric acid(SiO2-OSO3H),and catalytic amounts of ammonium bromide in CH2Cl2 in the presence of a few drops of water at room temperature.Excellent yields were obtained.

Chemoselective N-nitrosation of secondary amines under heterogeneous and mild conditions via in situ generation of HNO_2

A wide variety of secondary amines are chemoselectively subjected to N-nitrosation reaction with treatment of citric acid and NaNO2 in the presence of wet SiO2 （50%, w/w） in dichloromethane at room temperatture under heterogeneous conditions. The Nnitrosation method is very simple and products can be easily isolated with good to high yields.

Polyvinylpolypyrrolidonium tribromide as new and metal-free catalyst for the formylation and trimethylsilylation of hydroxyl group

Trimethylsilylation of alcohols was achieved using 1,1,1,3,3,3-hexamethyldisilazane（HMDS） as silylating agent,in the presence of polyvinylpolypyrrolidonium tribromide in acetonitrile at room temperature.Also a variety of alcohols were converted into alkyl formates by ethyl formate and a catalytic amount of polyvinylpolypyrrolidonium tribromide under solvent free conditions at room temperature.

An effcient,rapid and facile procedure for conversion of aldoximes to nitriles using triphenylphosphine and N-halo sulfonamides

N,N,N＇,N＇-Tetrabromobenzene-1,3-disulfonamide （TBBDA）/triphenylphosphine and N,N,N＇,N＇-tetra- chlorobenzene-1,3-disulfonamide （TCBDA）/triphenylphosphine have been introduced as highly efficient systems for the versatile conversion of aldoxime derivatives into nitriles. The process reported here is operationally simple and reactions have been mildly performed in dichloromethane at room temperature.

An efficient and versatile synthesis of aromatic nitriles from aldehydes

A simple and direct method has been developed for synthesis of nitriles based on one-pot reaction of aromatic aldehydes with three different kind of reagents： CeCl3.7H20/KI/H2O2, CeCl3.7H2O/KI/UHP and （NH4）2Ce（NO3）6/KI/H2O2 in aqueous ammonia.

Mononitration of phenol derivatives by guanidinium nitrate and silica sulfuric acid under mild conditions

A mixture of guanidinium nitrate and silica sulfuric acid acts as mild and heterogeneous media for the efficient mono nitration of phenolic compounds in dichloromethane at room temperature.

Three component reactions: An efficient and green synthesis of 3, 4-dihydropyrimidin-2-(1H)-ones and thiones using silica gel-supported L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate

An environmentally benign aqueous protocol for the synthesis of 3,4-dihydropyrimidin-2-（ 1 H）-ones and thiones promoted by a green catalyst, silica gel-supported L-pyrrolidine-2-carboxylic acid-4-hydrogen sulfate, has been developed. The use of nontoxic, thermally stable and inexpensive amino acid catalyst makes the process simple with minimal amount of chemical waste. Compared with classical Biginelli reaction conditions, this new method has the advantages of high yields and simple workup procedures.

2-(Sulfooxy)propane-1,2,3-tricarboxylic acid as novel and versatile catalyst for the formylation of alcohols and amines using ethyl formate under neat conditions

2-（Sulfooxy）propane-1,2,3-tricarboxylic acid（supported on silica gel） has been introduced as novel and green catalyst for the formylation of alcohols and amines with ethyl formate,as mild formylation agent,under neat conditions at room temperature.

Poly(4-vinylpyridinium tribromide) as metal-free,green and recoverable oxidizing polymer for the chemoselective oxidation of sulfides into sulfoxides

Poly（4-vinylpyridinium tribromide） was prepared from poly（4-vinylpyridin） and used for the selective oxidation of a variety of sulfides to the corresponding sulfoxides. The oxidation reaction was carried out heterogeneously in acetone/water, as green solvent, at room temperature.

One-pot and novel route for the synthesis of 4-substituted-1,2,4-triazolidine-3,5-diones

The efficient and one-pot synthesis of 4-substituted-l,2,4-triazolidin-3,5-dione derivatives （4- substituted urazoles） via combination of triphosgene, substituted anilines, and ethyl carbazate in the presence of cesium carbonate is presented.