Asymmetric Synthesis of Isoindolines Featuring N‐substituted Quaternary Carbon Centers through Stereoselective Intramolecular Aza‐Michael Reactions

This paper describes the asymmetric construction of N ‐substituted quaternary carbon centers through the phase‐transfer‐catalyzed stereoselective intramolecular aza‐Michael reaction of β,β‐disubstituted, α,β‐unsaturated esters, and nitriles with chiral sulfinamides used as nucleophiles. This reaction efficiently yielded chiral 1,1‐disubstituted isoindolines with yields ranging from 41% to 90% and excellent diastereoselectivities (diastereomeric ratio between 7.8:1 and > 20:1).