Cycloadditions of extended dipoles: reaction of imidoylazimines with ketens
Abstract
Ketens undergo 2 + 2 cycloaddition to the CN bond of the imidoylazimines (1) to give the β-lactams (2) which are cleaved on heating to give either benzocinnoline and 1,2,4,4-tetrasubstituted imidazolin-5-ones (5) or the triazolines (7), depending on the keten substituents.