Amino Acid‐Catalyzed Asymmetric Carbohydrate Formation: Organocatalytic One‐Step De Novo Synthesis of Keto and Amino Sugars

Abstract

AbstractA direct de novo synthesis of ketoses and amino sugars by amino acid‐catalyzed asymmetric aldol, Mannich and Michael reactions with dihydroxyacetone phosphate mimics as donors is presented. Proline, proline derivatives and thiazolidine‐4‐carboxylic acids catalyzed the asymmetric assembly of keto sugars and amino sugars in high yield with up to >99% ee. The organocatalytic C3+Cn methodology presented herein is a direct entry to the de novo synthesis of orthogonally protected C4, C5, and C6 ketoses, carbohydrate derivatives, amino and aza sugars and the total synthesis of polyoxamic acids. The addition of water significantly accelerated and improved the enantioselectivity of the proline‐mediated biomimetic asymmetric CC bond‐forming reactions.