This invention provides a convenient method for converting imines and other electrophiles into heterocyclic ring systems. The process does not require the use of metallic reagents, and is catalyzed by an organic heterocyclic carbene catalyst. Accordingly, it produces the desired compounds without the concomitant production of a large volume of metallic waste. Chiral heterocyclic carbene catalysts of the invention and methods of using these catalysts produce chiral heterocycles in high enantiomeric and diastereomeric excess.