Ruthenium(0)-sequential catalysis for the synthesis of sterically hindered amines by C-H arylation/hydrosilylation

We report sequential ruthenium(0)-catalysis for the synthesis of sterically-hindered amines via direct C-H arylation of simple imines and imine hydrosilylation. The method involves direct C-H arylation under neutral conditions with organoboranes enabled by ruthenium(0) catalysis. The catalytic hydrosilylation was performed in a one-pot fashion using Et₃SiH. The reaction is compatible with a broad range of electronically- and sterically-varied imines, enabling rapid production of valuable biaryl amines in good to excellent yields. The method constitutes a two-step, one-pot procedure to synthesize sterically-hindered amines from aldehydes. The utility of this atom-economic strategy is demonstrated in one-pot, three-component coupling, direct in situ aldehyde arylation and the use of transfer hydrogenation.