5 - Synthesis of azetidines by cycloaddition of imines to ketenes-II

Abstract

The research on procedures to synthesize the azetidine ring has advanced extraordinarily during the last few years. Numerous novel heteroatom-substituted ketenes are used efficiently in the Staudinger reaction. The development of a catalyzed reaction of ketenes and imines resulted in a practical method for the catalytic, asymmetric synthesis of β-lactams. Many important advancements have been seen in cyclization and cycloaddition approaches for the formation of β-lactams. The cycloadditions include Staudinger’s ketene-imine cycloadditions and related reactions.