Hydrosilylation of Carbonyl Compounds Catalyzed by a Nickel Complex Bearing a PBP Ligand

The efficient catalytic hydrosilylation of ketones and aldehydes has been investigated using a nickel pincer hydride complex supported by a diphosphino‐boryl ligand (PBP). It was found that the presence of the boryl group within the skeleton of the ligand has a beneficial effect on the catalytic activities observed for ketones compared to related pincer systems. The analysis of the reaction mechanism allows for the synthesis and characterization of a nickel alkoxide derivative by insertion of the carbonyl moiety into the Ni−H bond. Combined experimental and theoretical analysis (DFT) support a reaction mechanism that involves the initial formation of an alkoxide complex followed by reaction with the silane to release the corresponding silyl ether and regenerate the catalyst. A bis(ditertbutylphophino)boryl nickel hydride pincer complex has been used for the efficient catalytic reduction of aldehydes and ketones to the corresponding alcohols using silanes as reductants under mild reaction conditions.