Synthesis of Dimeric Methylzinc N,N-Bis(2-pyridylmethyl)carbamate via Addition of CO2 to a Methylzinc Amide

Exposure of a THF solution of bis(methylzinc) tert-butylamide bis(2-pyridylmethyl)amide (1) to a carbon dioxide atmosphere leads to formation of dimeric methylzinc bis(2-pyridylmethyl) carbamate (2). The preparation of 2 from 1 and CO2 is a two-step reaction and affords ligand redistribution after insertion of CO2 into the Zn-N bonds. The central structural fragment is an eight-membered (ZnO2C)(2) ring with tetracoordinate zinc atoms and planar C2N-CO2 carbamate units in a boat conformation.