ChemInform Abstract: Organocatalytic Asymmetric Mannich Reaction of 3‐Hydroxyoxindoles/3‐Aminooxindoles with in situ Generated N‐Boc‐Protected Aldimines for the Synthesis of Vicinal Oxindole—Diamines/Amino Alcohols.

Abstract

A highly efficient asymmetric Mannich reaction of 3-monosubstituted 3-aminooxindoles/3-hydroxyoxindoles with in situ generated N-Boc-protected aldimines catalyzed by the chiral bifunctional thiourea–tertiary amine catalyst has been developed. Under mild reaction conditions, a series of structurally diverse vicinal oxindole–diamines/amino alcohols were smoothly obtained in moderate to high yields (up to 99%) with good to excellent diastereoselectivities and enantioselectivities (up to 95:5 dr and 96% ee). The synthetic application of this protocol was also demonstrated by the versatile transformation of chiral vicinal oxindole–diamine/amino alcohol into spirocyclic oxindoles.