Substrate‐Controlled Diastereoselectivity Switch in Catalytic Asymmetric Direct Mannich Reaction of Glycine Derivatives with Imines: From <i>anti</i>‐ to <i>syn</i>‐α,β‐Diamino Acids

Abstract

Back and forth: A diastereoselectivity switch has been devised in the Fesulphos–CuI-catalyzed glycine direct Mannich reaction with N-(8-quinolyl)sulfonyl imines by tuning the steric and electronic properties of the glycine component (see scheme). α,β-Diamino acids of syn configuration are produced under high diastereo- and enantiocontrol with glycinate esters derived from electron-deficient benzophenone-type ketimines, in contrast to aldimine-derived pronucleophiles that lead to anti-configured products.