Oxygen‐Linked Cyclopentadienyl Rhodium(III) Complexes‐Catalyzed Asymmetric C−H Arylation of Benzo[<i>h</i>]quinolines with 1‐Diazonaphthoquinones
Chongqing Pan, Si‐Yong Yin, Shao‐Bo Wang, Qing Gu, Shu‐Li You
Abstract
Abstract Chiral cyclopentadienyl rhodium (CpRh) complex‐catalyzed asymmetric C−H functionalization reactions have witnessed a significant progress in organic synthesis. In sharp contrast, the reported chiral Cp ligands are limited to C‐linked Cp and are often synthetically challenging. To address these issues, we have developed a novel class of tunable chiral cyclopentadienyl ligands bearing oxygen linkers, which were efficient catalysts for C−H arylation of benzo[ h ]quinolines with 1‐diazonaphthoquinones, affording axially chiral heterobiaryls in excellent yields and enantioselectivity (up to 99 % yield, 98.5:1.5 er). Mechanistic studies suggest that the reaction is likely to proceed by electrophilic C−H activation, and followed by coupling of the cyclometalated rhodium(III) complex with 1‐diazonaphthoquinones.