Electrochemical Nickel-Catalyzed C(sp2)-H Functionalization of Tropones with Aldehydes

A direct electroreductive functionalization of tropones employing aldehydes as alkylating agents is reported. This C(sp2)-H functionalization process leverages the mediation of electroactive nickel complexes, enabling a wide range of both native and substituted tropones (44 examples) to be alkylated selectively at the α-position in high yields (up to 90%). Combined electrochemical, spectroelectrochemical, and computational analyses disclosed the whole mechanistic pathway and revealed the key role played by reduced Ni complexes in activating the tropone core toward condensation with the aldehydes.