Rhodium(I)-Catalyzed Direct Enantioselective C-H Functionalization of Indoles

A highly regiospecific vinylogous carbene insertion protocol for direct asymmetric C-H functionalization of indoles with arylvinyldiazoacetates has been developed. Under the catalysis of simple Rh(I)/chiral diene complexes, the reaction occurs solely at the vinylogous position of the vinylcarbenoid with exceptional E selectivity and enantiocontrol. It provides an efficient way to obtain an interesting class of chiral indole scaffolds bearing an alpha,beta-unsaturated ester unit and a gem-diaryl carbon stereocenter in good yields (<99%) with excellent enantioselectivities (<96%) at room temperature.