Versatile Cobalt(III)-Catalyzed Chemoselective C−H Alkylation with Polyfunctional Alkylzinc Reagents

C(sp2)−C(sp3) bond-forming reactions, which can increase the Fsp3 carbons, have emerged as a valuable approach for drug discovery. Herein, we report on the cobalt(III)-catalyzed chemoselective C(sp2)−H alkylation using bifunctional alkylzinc reagents as alkylation agents. The mild nucleophilic nature of organozinc reagents and the mild reaction conditions translated into a broad functional group tolerance and thus enabled the late-stage functionalization of highly functionalized drug molecules. In addition, the use of an earth-abundant cobalt catalyst and low-toxic zinc reagents highlighted an environmentally benign system.