Nickel-catalyzed cooperative B-H bond activation for hydroboration of N -heteroarenes, ketones and imines

We report two air-stable nickel(II) half-sandwich complexes, Cp *Ni(1,2-Cy 2 PC 6 H 4 O) ( 1 ) and Cp *Ni(1,2Ph 2 PC 6 H 4 NH) ( 2 ), for cooperative B-H bond activation and their applications in catalytic hydroboration of unsaturated organic compounds. Both 1 and 2 react with HBpin by adding the B-H bond across the Ni -X bond (X = O or N), giving rise to the 18-electron Ni(II) -H active species, [H 1 (Bpin)] and [H 2 (Bpin)]. Subtle tuning of the Ni -X pair and the supporting ancillary phosphine have a significant effect on the reactivity and catalytic performance of Cp *Ni(1,2-R 2 PC 6 H 4 X). Unlike [H 2 (Bpin)], the activation of HBpin in [H 1 (Bpin)] is reversible, which enables the Ni -O complex to be an effective cooperative catalyst in the hydroboration of N -heteroarenes, and as well as ketones and imines.& COPY; 2023 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.