Catalytic asymmetric synthesis of (-)-ritodrine hydrochloride via silyl enol ether amination using dirhodium(II) tetrakis [tetrafluorophaloyl-(S)-tert-leucinate]

Article abstract of DOI:10.3987/COM-08-S(N)121

A catalytic asymmetric synthesis of (-)-ritodrine hydrochloride was achieved, incorporating an enantioselective amination of (Z)-silyl enol ether derived from 4-benzyloxypropiophenone with [(2-nitrophenylsulfonyl)imino]phenyliodinane (NsN=IPh) and a chelation-controlled reduction of the ketone carbonyl group with Zn(BH₄)₂ as the key steps. The use of dirhodium(II) tetrakis[tetrafluorophthaloyl-(S)-tert-leucinate] as a catalyst produced the targeted α-amino ketone in 94% yield with 91% ee.