Diborylmethyl Group as a Transformable Building Block for the Diversification of Nitrogen-Containing Molecules

The development of new approaches to installing diverse carbon fragments to a nitrogen atom has attracted considerable attention in chemical science. While numerous strategies have been devised to forge C(sp(3))-N bonds, one conceptually powerful and straightforward approach is to insert a transformable sp(3)-carbon unit onto a nitrogen atom for modular diversification. Here we describe the successful synthesis of halo-diborylmethanes and their applications to the preparation of nitrogen-substituted diborylmethanes through their homologative coupling with a variety of nitrogen nucleophiles including biologically relevant molecules. This process exhibits a remarkably broad substrate scope, and the usefulness of the obtained compounds is demonstrated by the modular diversification of the diborylmethyl group to access various nitrogen-containing molecules.