A cobalt−chiral phosphoramidite catalyst pro- motes enantioselective imine-directed C2-alkylation of Boc- protected indoles with styrenes. The reaction affords 1,1- diarylethane products in moderate to good yields with good enantioselectivities under mild conditions. A deuterium-labeling experiment suggests that the enantioselectivity is controlled by both the styrene insertion and the C−C reductive elimination steps.