A Simple and Useful Synthetic Protocol for Selective Deprotection oftert-Butyldimethylsilyl (TBS) Ethers
作者:Abu T. Khan、Subrata Ghosh、Lokman H. Choudhury
DOI:10.1002/ejoc.200400031
日期:2004.5
A wide variety of tert-butyldimethylsilyl ethers 1 can be easily cleaved to the corresponding parent hydroxyl compound 2 in the presence of 5 mol % of acetonyltriphenylphosphonium bromide (ATPB) at room temperature. In addition, tert-butyldiphenylsilyl ethers can also be cleaved by using 20 mol % of the same catalyst. Alkyl tert-butyldimethylsilyl ethers can be deprotected to the hydroxyl compounds
Selective hydrogenation of substituted dienes catalyzed by an organoyttrium complex
作者:Gary A. Molander、John O. Hoberg
DOI:10.1021/jo00038a004
日期:1992.6
Cp*2YMe(THF) has been developed as an efficient catalyst for the selective reduction of substituted dienes.
Efficient Method for the Deprotection of <i>tert</i>-Butyldimethylsilyl Ethers with TiCl<sub>4</sub>−Lewis Base Complexes: Application to the Synthesis of 1β-Methylcarbapenems
TiCl4-Lewis base (AcOEt, CH3NO2) complexes smoothly deprotected tert-butyldimethylsilyl (TBDMS) ethers. The reaction velocity with these complexes, which seemed less reactive due to the influence of Lewis bases, was considerably greater than that with TiCl4 alone. Selective desilylations between aliphatic and aromatic TBDMS ethers (1 and 5), between 1 and benzyl, allyl, tosyl, methoxyphenyl, and chloroacetyl ethers (13, 14, 15, 16, and 17), and between TBDMS and TBDPS ethers (18 and 19) were successfully performed. Desilylation of TBDMS-aldol, acyloin, and beta-lactam analogues 9-12 proceeded smoothly due to anchimeric assistance by the neighboring carbonyl groups. The present method was successfully applied to the practical synthesis of 1 beta-methylcarbapenems 20a'-f'.