Abstract: | Tridentate N,N,N‐pyridinebisimidazolines have been studied as new ligands for the enantioselective transfer hydrogenation of prochiral ketones. High yields and excellent enantioselectivity up to >99 % ee have been achieved with an in situ generated catalytic system containing dichlorotris(triphenylphosphine)ruthenium and 2,6‐bis‐([4R,5R]‐4,5‐diphenyl‐4,5‐dihydro‐1H‐imidazol‐2‐yl)‐pyridine ( 3a ) in the presence of sodium isopropoxide. |