Direct Enantioselective and Regioselective Alkylation of β,γ-Unsaturated Carboxylic Acids with Chiral Lithium Amides as Traceless Auxiliaries
作者:Kai Yu、Bukeyan Miao、Wenqi Wang、Armen Zakarian
DOI:10.1021/acs.orglett.9b00587
日期:2019.3.15
Efficient asymmetric alkylation of β,γ-unsaturated carboxylic acids without prior functionalization is enabled by chiral lithium amides. Enantioselectivity is imparted by a putative mixed lithium amide–enediolate aggregate that acts a traceless auxiliary formed in situ, allowing for a direct asymmetric alkylation and a simple recovery of the chiral reagent.
β,γ-不饱和羧酸的有效不对称烷基化无需事先官能化就可以通过手性锂酰胺实现。对映选择性是由假定的酰胺基-烯二醇锂混合聚集体赋予的,该聚集体发挥就地形成的无痕助剂的作用,允许直接不对称烷基化和简单回收手性试剂。