Enantioselective synthesis of 4-substituted 2-pyrrolidinones by site- selective C-H insertion of α-methoxycarbonyl-α-diazoacetanilides catalyzed by dirhodium(II) tetrakis[N-phthaloyl-(S)-tert-leucinate]

Article abstract of DOI:10.1016/S0040-4039(97)10493-2

Site- and enantioselective intramolecular C-H insertion of α- methoxycarbonyl-α-diazoacetamides has been achieved by exploiting a p- nitrophenyl group as the N-substituent and dirhodium(II) tetrakis[N- phthaloyl-(S)-tert-leucinate] as catalyst, leading to the formation of 4 substituted 2-pyrrolidinone derivatives of up to 82% ee. The efficiency of the present protocol has been verified well by a short-step synthesis of (R)- (-)-baclofen.