Lithium n-benzyltrimethylsilylamide (LSA): a new reagent for conjugate addition - enolate trapping reactions
作者:Naoki Asao、Tadao Uyehara、Yoshinori Yamamoto
DOI:10.1016/s0040-4020(01)86664-3
日期:1988.1
4-manner, though the reaction of ordinary lithium amides with α,β-unsaturated carbonyl compounds is accompanied with a 1,2-addition and hydrogen abstraction at the γ-position. The conjugate addition via LSA followed by enolate trapping with electrophiles produces the corresponding α-substituted β-amino esters, which are, in turn, converted into β-lactams and α-substituted α, β-unsaturated esters.
尽管普通锂酰胺与α,β-不饱和羰基化合物的反应伴随有1,2-加成和γ-氢的夺氢,但N-苄基三甲基甲硅烷基锂(LSA)可以1,4-方式添加到巴豆酸中。位置。经由LSA的共轭添加,然后用亲电试剂进行烯醇化捕集,产生相应的α-取代的β-氨基酯,其随后转化为β-内酰胺和α-取代的α,β-不饱和酯。