Synthesis of Optically Active Oxazolines by an Organocatalytic Isocyanoacetate Aldol Reaction with α-Keto Esters

Abstract

An enantioselective [3+2] cyclization is reported for the construction of a chiral oxazoline skeleton in moderate yield and up to 97% ee. The reactivity and stereochemical discrimination originate from the noncovalent interaction and orientation of a bifunctional catalyst. The novel combination of an α-keto ester and an α-isocyanoacetate establishes an oxazoline which could be a potential chiral ligand for metal-mediated catalysis, and also could be easily converted into an optically active β-hydroxy-α-amino acid.