We describe a strategy for intermolecular branched-selective a-alkylation of ketones using simple alkenes as the alkylating agents. Enamides derived from isoindolin-1-one provide an excellent directing template for catalytic activation of ketone a-positions. High branched selectivity is obtained for both aliphatic and aromatic alkenes using a cationic iridium catalyst. Preliminary mechanistic study favors an Ir-C migratory insertion pathway.