Department of Chemistry and Biochemistry , University of California , Santa Barbara , California 93106 , United States.
Org Lett. 2019 Mar 15;21(6):1930-1934. doi: 10.1021/acs.orglett.9b00587. Epub 2019 Mar 5.
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.
手性锂酰胺能够实现β,γ-不饱和羧酸的高效不对称烷基化反应,无需预先官能化。通过假定的混合锂酰胺-烯二醇酯聚集体赋予对映选择性,该聚集体充当原位形成的无痕迹辅助试剂,允许直接进行不对称烷基化反应,并简单回收手性试剂。