Rhodium‐Catalyzed Asymmetric Transfer Hydrogenation of Aryl Ketones Involving Free Phenolic Hydroxyl Group(s)

A straightforward asymmetric transfer hydrogenation for accessing enantiomerically enriched secondary benzyl alcohols involving free phenolic hydroxyl group(s) under mild conditions was developed. Various of optical pure aryl alcohols with a remarkable functional group compatibility were achieved with 78 %–97 % yields, 84 %–>99 % ee's and up to 10 000 TON. This rhodium‐catalyzed reaction could be performed in a gram‐scale without loss of the efficiency. Furthermore, the synthetic utility has also been demonstrated in the asymmetric synthesis of (S)‐adrenaline and (S)‐phenylephrine. A straightforward asymmetric transfer hydrogenation for accessing enantioenriched secondary benzyl alcohols involving free phenolic hydroxyl group(s) under mild conditions was developed. The synthetic potential of this method was also demonstrated by a gram‐scale synthesis and further conversion into epinephrine analogues.