Ni-catalyzed addition of arylborons to alkenes for the synthesis of quaternary carbon centers

All-carbon quaternary centers are prevalent motifs, thus attracting increasing interest from the organic community. We present here a nickel-catalyzed Markovnikov-selective addition of stable organoborons to simple alkenes, enabled by a diimine ligand. This robust method provides efficient access to quaternary carbon centers in high yields. Furthermore, with a bulky chiral diimine ligand, quaternary carbon stereocenters can be readily prepared. Mechanistic investigations indicate the involvement of an unusual nickel migration from an alkyl nickel to an aryl nickel species.