Addition of N-heterocyclic carbenes to imines: phenoxide assisted deprotonation of an imidazolium moiety and generation of breslow intermediates derived from imines.

Reactions between imidazolium-imine salts and base result in C-C bond formation via intermediate N-heterocyclic carbenes. In the presence of a proximal OH moiety, carbene formation occurs via intramolecular deprotonation by phenoxide. For simple imines, a reactive Breslow-type intermediate gives access to new heterocycles with the formation of six- and seven-member rings.