eco-friendly protocol for the chemoselective protection of benzylic and primary and less hindered secondary aliphatic alcohols and phenols as trimethylsilyl ethers and different types of amines as N-tert-butylcarbamates is developed using rice husk (RiH) as the catalyst. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols and amines with acetic anhydride. Easy work-up, relatively
Abstract Hexamethyldisilazane (HMDS) in pesence of a catalytic amount of Envirocat EPZGR silylates different alcohols in high yields with absolute chemoselectivity. R: Registered trade mark of Contract Chemicals, England.
Efficient Trimethylsilylation of Alcohols and Phenols with HMDS in the Presence of a Catalytic Amount of 1,3-Dibromo-5,5-Dimethylhydantoin (DBDMH) as a Safe and Cheap Industrial Chemical
1,3-Dibromo-5,5-dimethylhydantoin (DBDMH) is found to be an effective catalyst for trimethylsilylation various alcohols and phenols with hexamethyldisilazane (HMDS) in dichloromethane at room temperature.
1,3-Dichloro-5,5-Dimethylhydantoin (DCH) and Trichloromelamine (TCM) as Efficient Catalysts for the Chemoselective Trimethylsilylation of Hydroxyl Group with 1,1,1,3,3,3-Hexamethyldisilazane (HMDS) Under Mild Conditions
作者:Arash Ghorbani-Choghamarani、Kamal Amani、Mohammad Ali Zolfigol、Maryam Hajjami、Roia Ayazi-Nasrabadi
DOI:10.1002/jccs.200900037
日期:2009.4
A highly convenient method for the trimethylsilylation of alcohols and phenols via treatment by hexamethyldisilazane in the presence of 1,3–dichloro‐5,5–dimethylhydantoin (DCH) and/or trichloromelamine (TCM) as a catalyst has been developed. A wide variety of hydroxylgroups were selectively protected in CH2Cl2/CH3CN undermildconditions.
(PhCH<sub>2</sub>PPh<sub>3</sub>)<sup>+</sup>Br<sub>3</sub><sup>−</sup>: A Versatile Reagent for the Preparation, Deprotection, and Oxidation of Trimethylsilyl Ethers
作者:F. Shirini、G. H. Imanzadeh、A. R. Mousazadeh、I. Mohammadpoor-Baltork、A. R. Aliakbar、M. Abedini
DOI:10.1080/10426500902915440
日期:2010.2.23
Benzyltriphenylphosphonium tribromide (BTPTB), as a stable solid reagent, is easily prepared by the reaction of benzyltriphenylphosphonium bromide with Br2. This reagent can be used as an efficient catalyst for the conversion of alcohols to their corresponding trimethylsilyl ethers (TMS ethers) with hexamethyldisilazane (HMDS). Desilylation of TMS ethers is also catalyzed by BTPTB in MeOH at room temperature