Cobalt(II) and (I) Complexes of Diphosphine‐Ketone Ligands: Catalytic Activity in Hydrosilylation Reactions

The hydrosilylation of unsaturated compounds homogeneously catalyzed by cobalt complexes has gained considerable attention in the last years, aiming at substituting precious metal‐based catalysts. In this study, the catalytic activity of well‐characterized Co(II) and Co(I) complexes of the (pTol)dpbp ligand is demonstrated in the hydrosilylation of 1‐octene with phenylsilane. The Co(I) complex is the better precatalyst for the mentioned reaction under mild conditions, at 1 mol‐% catalyst, 1 h, room temperature, and without solvent, yielding 84 % of octylphenylsilane. Investigation of the substrate scope shows lower performance of the catalyst in styrene hydrosilylation, but excellent results with allylbenzene (84 %) and acetophenone (> 99 %). This catalytic study contributes to the field of cobalt‐catalyzed hydrosilylation reactions and shows the first example of catalysis employing the dpbp ligand in combination with a base metal.