Iridium(III)- and rhodium(III)- catalyzed coupling of anilines with alpha-diazoesters via chelation- assisted C-H activation

Iridium and rhodium complexes exhibited complementary activity in the coupling of N-functionalized anilines with alpha-diazoesters via C-H activation. The coupling with alpha-diazo beta-ketoesters was realized under Ir(III) catalysis to afford ester-functionalized indoles. In contrast, coupling with alpha-diazomalonates under Rh(III) catalysis afforded alkylation products without any annulation. Mechanistic studies have been performed and an iridacycle has been isolated as an intermediate.