Author:

Keywords:

Science & Technology, Physical Sciences, Chemistry, Inorganic & Nuclear, Chemistry, Organic, Chemistry, PALLADIUM(0) COMPLEX, CATALYTIC-ACTIVITY, MECHANISM, NICKEL, CHLORIDES, LIGAND, TRIFLUOROMETHYLATION, PRECATALYSTS, AMINATION, PHOSPHINE, 0302 Inorganic Chemistry, 0305 Organic Chemistry, 0399 Other Chemical Sciences, Organic Chemistry, 3402 Inorganic chemistry, 3406 Physical chemistry

Abstract:

Oxidative addition of aryl halides to Ni(0) is a ubiquitous elementary step in cross-coupling and related reactions, usually producing a square-planar Ni(II)-aryl intermediate. Here we show that a triphosphine ligand supports oxidative addition at a tris-ligated Ni(0) center to cleanly form stable five-coordinate Ni(II)-aryl compounds. Kinetic and computational studies support a concerted, two-electron mechanism rather than radical halogen abstraction. These results support the idea that oxidative addition to triphosphine Ni(0) species may be more generally involved in Ni/phosphine catalytic systems.