Intramolecular metalloamination of N,N-dimethylhydrazinoalkenes: a versatile method to access functionalized piperidines and pyrrolidines.

Highly diastereoselective metalloamination/cyclization reactions of zinc(II) hydrazides obtained through reaction of diethylzinc with N,N-dimethylhydrazinoalkenes are described. The resulting organozinc intermediates undergo facile allylation and acylation, in situ, to provide the corresponding functionalized piperidines and pyrrolidines.