10.1016/j.tetlet.2007.10.087
The research focuses on the asymmetric synthesis of phenylglycine derivatives through the enantioselective amination of silylketene acetals using (N-arylsulfonylimino)phenyliodinanes, catalyzed by chiral dirhodium(II) carboxylates. The study reports the first catalytic enantioselective amination of this kind, utilizing dirhodium(II) tetrakis[N-tetrachlorophthaloyl-(S)-tert-leucinate], Rh2(S-TCPTTL)4, as the catalyst. The reaction involves silylketene acetals derived from methyl phenylacetates and [N-(2-nitrophenylsulfonyl)imino]phenyliodinane (NsN = IPh), and it proceeds in benzene at room temperature, yielding N-(2-nitrophenylsulfonyl)phenylglycine derivatives with high yields and enantioselectivities of up to 99% ee. The experiments involved various nitrene precursors, solvents, and silylketene acetals to optimize the reaction conditions. The analyses used to determine the success of the reactions included high-performance liquid chromatography (HPLC) with chiral stationary phases to assess enantioselectivity and product yields.
