Coordination and derivatization of 3, 4, and 6-membered nitrogen heterocycles at a chiral tungsten(II) center

A variety of nitrogen heterocycles have been coordinated to a chiral tungsten center. Aziridine and azetidine and amido complexes have been prepared. Oxidation of the amido complex derived from azetidine provided a 1-azetine complex. Addition of a Grignard reagent to the azetine complex led to a methylazetidine complex (96:4 dr).