Indium (Ⅲ) Tribromide : An Excellent Catalyst for Biginelli Reaction

A highly efficient catalyst indium (III) tribromide is used to synthesize 5-alkoxy- carbonyl-4-hydrocarbyl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of -keto ester, aldehydes and urea through improved Biginelli reaction.

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.

Preparation of aromatic nitriles via direct oxidative conversion of benzyl alcohols,aldehydes and amines with pentylpyridinium tribromide in aqueous NH_4OAc

Pentylpyridinium tribromide and aqueous ammonium acetate was used for the rapid oxidative conversion of benzyl alcohols, benzaldehydes and benzyl amines to the corresponding benzonitriles in good to excellent yields. This simple, mild and one-pot system provides easy workup and separation of the products.

Phase chemistry of cesium bromide and praseodymium tribromide reacting in hydrobromic acid

Early in the 1980 s, Meyer dissolved appropriate amounts of CsCl and PrCl3·7H2O ina small amount of concentrated hydrochloric acid for getting CsPr2Cl7（hyd.）, and then thesample CsPr2Cl7（hyd.）was dehydrated by heating in HCl stream at high temperature. Thereaction equation is as follows:

Allyltin tribromide: A versatile reagent involved in the ring-opening of epoxides

This paper presents a versatile reagent for epoxide cleavage.The allyltin tribromide could act as a novel and easily prepared allylation reagent and halide atom donor to convert epoxides to the corresponding homoallyl alcohols and halohydrins in high yields with excellent regioselectivities under mild reaction conditions,respectively.It could also act as a Lewis acid to catalyze the ring opening reactions of epoxides with alcohols.

Boron(III) Tribromide or Titanium(IV) Bromide and Lewis Base Promoted Baylis-Hillman Reaction

It was found that, when the Baylis-Hillman reaction of arylaldehydes withmethyl vinyl ketone was carried out at below - 20℃ in the presence of boron (Ⅲ) tribromide ortitanium (Ⅳ) bromide using a catalytic amount of Lewis base such as amine, the brominated compoundsand the Baylis-Hillman adducts could be obtained as the major products in good yields for variousaryl aldehydes. But at room temperature, the elimination products were the major products. Inaddition, the palladium catalyzed allylic substitution reactions of the e-limination products werealso examined.

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.

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.

Reductive Deoxygenation of Carbonyl to Methylene by LiAlH4/InBr3

The reductive deoxygenation of aldehydes and ketones into the corresponding alkanes is accomplished by LiAlH4, in the presence of Lewis acid InBr3. It provides a convenient method to complete the transformation from carbonyl compounds to alkanes.

{[K.18-Crown-6]Br3}n:保护胺和醇的三溴化催化剂(英文)

{[K.18-Crown-6]Br3}n , a unique tribromide-type catalyst, was utilized for the N-boc protection of amines and trimethylsilylation (TMS) and tetrahydropyranylation (THP) of alcohols. The method is general for the preparation of N-boc derivatives of aliphatic (acyclic and cyclic) and aromatic, and primary and secondary amines and also various TMS-ethers and THP-ethers. The simple separation of the catalyst from the product is one of the many advantages of this method.