Hybrid NH2-benzimidazole ligands for efficient Ru-catalyzed asymmetric hydrogenation of aryl ketones.

Readily available hybrid NH(2)/benzimidazole ligands (R-bimaH, 1) dramatically influence the outcome of established Ru-based catalysts during asymmetric hydrogenation of aryl ketones. The benzimidazole functionality results in reversal of the typically observed chiral induction and allows for hydrogenation to be uncharacteristically conducted in nonprotic solvents. The developed systems efficiently catalyzed the AH of a number of ketones in up to 99% ee.