Advances in synthesis of monocyclic beta-lactams

Abstract

A review. Recent years have witnessed significant advancement in cycloaddn. and cyclization strategies for the synthesis of monocyclic β-lactams. Cycloaddns. include the Staudinger's ketene - imine cycloaddns. and related reaction. Cyclization reactions are reported to furnish β-lactams through N1-C2, N1-C4 and C3-C4 bond formations employing substrates like β-amino esters, β-amino alcs., β-hydroxamate esters, and α-amino diazocarbonyls, etc. Some other strategies are silyl carbonylation reactions, ring-enlargement of aziridines, cleavage of one ring of a bicyclic β-lactam, and functional group transformations on the β-lactam rings. Recently, some multi-component reactions have also been designed. This article reviews the advances made in synthetic approaches to monocyclic β-lactams during last five years. [on SciFinder(R)]