Facile kinetic induction of a dihydropyridide to pyrrolide ring contraction

Abstract

Reactions between magnesium 1,4-dihydropyridide or 1,2-dihydro-iso-quinolide derivatives and carbodiimides, RNCNR, generally result in Mg–N insertion and formation of guanidinate complexes. More sterically perturbed systems with N-aryl carbodiimide substitution, however, follow a divergent course of reaction initiating heterocyclic ring contraction and pyrrolide formation under unprecedentedly mild conditions.