Efficient Chemoselective Deprotection of Silyl Ethers Using Catalytic 1‐Chloroethyl Chloroformate in Methanol.

Abstract

Deprotection O 0345Efficient Chemoselective Deprotection of Silyl Ethers Using Catalytic 1-Chloroethyl Chloroformate in Methanol. -By controlling the amount of chloroformate catalyst (0.01 to 8 mol%) and the reaction time, chemoselective desilylation can be performed in the presence of bulkier silyl groups and other acid-sensitive alcohol protecting groups. In addition, the deprotection of alkylsilyl ethers proceeds selectively in the presence of aryl silyl ethers. -(YEOM, C.-E.; KIM, Y.

Chemoselective Deprotection of Triethylsilyl Ethers

“…[4] The selective deprotection of triethylsilyl (TES) ethers in the presence of tert -butyldimethylsilyl (TBDMS) can be carried out using 10% Pd/C in methanol or 95% ethanol,[5] mesoporous silica MCM-41/MeOH,[6] IBX in dimethyl sulfoxide (DMSO),[7] and 1-chloroethyl chloroformate in methanol. [8] These methods work well in many cases, however all require expensive reagents or catalysts. Our interest in synthesizing 5,6-dihydro-5-(α-thyminyl)-thymine has led us to develop a new method for the chemoselective deprotection of triethylsilyl ethers that is both efficient and economical.…”