A Polymer-Supported Chiral Fluorinated Dirhodium(II) Complex for Asymmetric Amination of Silyl Enol Ethers

The immobilization of dirhodium(II) tetrakis[N-tetrafluorophthaloyl-(S)-tert-leucinate], [Rh-2(S-TFPTTL)(4)], has been accomplished by co-polymerization of a dirhodium(II) complex-containing monomer with styrene and 1,6-bis(4-vinylbenzyloxy) hexane as a flexible cross-linker. The polymer-supported chiral fluorinated dirhodium(II) complex catalyzed the amination of silyl enol ethers with [N-(2-nitrophenylsulfonyl)imino]phenyliodinane (NsN=IPh) to provide alpha-amino ketones in high yields with high levels of enantioselectivity and could be used up to 20 times as the catalyst readily withstood stirring in the presence of the solid reactant.