Kinetic Resolution of α‐Silyl‐Substituted Allylboronate Esters via Chemo‐ and Stereoselective Allylboration of Aldehydes
Jinyoung Park, Yongsuk Jung, Jeongho Kim, Eunsung Lee, Sarah Yunmi Lee, Seung Hwan Cho
Abstract
Abstract We describe the kinetic resolution of α‐silyl‐substituted allylboronate esters via chiral phosphoric acid‐catalyzed chemo‐, diastereo‐ and enantioselective allylboration of aldehydes. This process provides two synthetically versatile enantioenriched compounds, ( Z )‐δ‐silyl‐substituted anti ‐homoallylic alcohols and α‐silyl‐substituted allylboronate esters, with a selectivity factor up to 328. We propose that the reaction proceeds through a closed chair‐like transition state with the silane moiety occupying a pseudo‐axial position, thus readily resolving α‐silyl‐substituted allylboronate esters. The synthetic utility of the obtained enantioenriched compounds is highlighted by their further transformations to give a diverse set of enantioenriched molecules. magnified image