ChemInform Abstract: Catalytic Aldol—Cyclization Cascade of 3‐Isothiocyanato Oxindoles with α‐Ketophosphonates for the Enantioselective Synthesis of β‐Amino‐α‐hydroxyphosphonates.

Abstract

A cascade aldol–cyclization reaction between 3-isothiocyanato oxindoles and α-ketophosphonates has been developed for the synthesis of β-amino-α-hydroxyphosphonate derivatives. Catalyzed by a quinine-based tertiary amino-thiourea derivative, this reaction delivers 2-thioxooxazolidinyl phosphonates based on a spirooxindole scaffold bearing two contiguous quaternary stereogenic centers in high yields with excellent diastereo- (up to >20:1 dr) and enantioselectivities (up to >99:1 er).