N-Boc-aminals as easily accessible precursors for less accessible N-Boc-imines: facile synthesis of optically active propargylamine derivatives using Mannich-type reactions
We developed a facile and practical synthesis of N-Boc-aminals, which can be used as precursors for less accessible N-Boc-imines. Aminals were obtained via simple dehydration condensation reactions of t-butyl carbamate (BocNH2) and various aldehydes in acetic anhydride, followed by filtration and washing with hexane. The obtained N-Boc-alkynylaminals could be successfully applied in enantioselective
Trimethylchlorosilane-promoted aza-Mannich reaction of enecarbamates and aldimines
作者:Pengcheng Wu、Deqin Lin、Xiaoxia Lu、Li Zhou、Jian Sun
DOI:10.1016/j.tetlet.2009.09.097
日期:2009.12
A trimethylchlorosilane-promoted aza-Mannich reaction is reported utilizing enecarbamates as the nucleophile and aromatic N-Boc aldimines as the electrophile. A variety of nucleophiles and electrophiles are tolerated by the reaction conditions, delivering the adduct products in excellent yields with high E-stereoselectivities. (C) 2009 Elsevier Ltd. All rights reserved.