Deprotection of tert-butyldimethylsilyl (TBDMS) ethers using efficient and recyclable heterogeneous silver salt of silicotungstic acid catalyst under mild reaction condition

Abstract

Deprotection of various substituted alkyl and phenolic TBDMS ethers were carried out using prepared silver exchanged silicotungstic acid (AgSTA) salt as heterogeneous catalyst in methanol at room temperature. The Brönsted acidic protons of silicotungstic acid were substituted by Lewis acidic silver molecule and prepared heterogeneous AgSTA catalyst which characterized using different spectroscopic and analytical methods. 0.2equiv. of AgSTA catalyst showed tremendous catalytic activity in the desilylation of alkyl and phenolic TBDMS ethers under mild reaction condition in methanol to produce respective alcohol in excellent yield. On screening, 100% conversion of reactants and up to 92.0% yield of respective alcohol in 40min reaction time was achieved using 0.2equiv. of AgSTA catalyst. The solid AgSTA catalyst was separated from the reaction mixture by simple filtration process at the end of reaction and reused for several times without significant loss of catalytic activity. The present eco-friendly catalytic system is found to be very convenient, high yielding, fast and clean method for desilylation of alkyl as well as phenolic silyl ethers even in existence of other sensitive organic functional groups such as aldehyde, methoxy, and acetate under mild reaction condition.