Novel Protocol for the Synthesis of Organic Ammonium Tribromides and Investigation of 1,1′-(Ethane-1,2-diyl)dipiperidinium Bis(tribromide) in the Silylation of Alcohols and Thiols
作者:Rupa R. Dey、Bappi Paul、Siddhartha S. Dhar、Sushmita Bhattacharjee
DOI:10.1246/cl.140564
日期:2014.10.5
A novel and efficient protocol for the synthesis of organic ammonium tribromides (OATBs) is developed by using inexpensive and eco-friendly periodic acid as an oxidant for the conversion of Br− to Br3−. The method does not use any mineral acid and metal oxidants. The protocol is utilized to synthesize a new bis(tribromide) viz., 1,1′-(ethane-1,2-diyl)dipiperidinium bis(tribromide) (EDPBT). EDPBT is investigated as a catalyst in the silylation of alcohols and thiols by HMDS (hexamethyldisilazane) under solvent-free conditions.
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.
Chemoselective Protection of Hydroxyl Groups and Deprotection of Silyl Ethers
作者:Babasaheb P. Bandgar、Suhas P. Kasture
DOI:10.1007/s007060170051
日期:2001.9
Trimethylsilylation of alcohols and phenols is carried out using hexamethyldisilazane and LiClO4 under microwave irradiation and neutral conditions. The deprotection of silyl ethers is carried out similarly using natural kaolinitic clay and a few drops of water.
at room temperature. While, under the same reaction conditions [Sn IV (TPP)Cl 2 ] is less efficient to catalyze these reactions. One important feature of this catalyst is its ability in the chemoselective silylation of primary alcohols in the presence of secondary and tertiaryalcohols and phenols. The catalyst was reused several times without loss of its catalytic activity.
Fast and efficient method for Silylation of alcohols and phenols with HMDS in the presence of bis-thiourea complexes of cobalt, nickel, copper and zinc chlorides
作者:Behzad Zeynizadeh、Serve Sorkhabi
DOI:10.1080/10426507.2017.1417294
日期:2018.3.4
GRAPHICAL ABSTRACT ABSTRACT Bis-thiourea complexes of cobalt, nickel, copper and zinc chlorides were usedefficiently for rapid and efficient trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS) in CH3CN. All reactions were carried out at roomtemperature within immediate-120 min timeframe to afford trimethylsilyl ether derivatives in high to excellent yields. Investigation