Cobalt-Catalyzed Syntheses of Esters and Carboxylic Acids from Alkenes Promoted by Light

Alkoxy- and hydroxycarbonylations of alkenes are widely useful transformations for the preparation of esters and carboxylic acids, respectively. Catalytic systems using earth-abundant, first-row metals hold significant promise in increasing the scope and sustainability of these processes, but general methods remain virtually undeveloped. Herein, we report alkene alkoxycarbonylations and hydroxycarbonylations catalyzed by unmodified, inexpensive cobalt carbonyl under mild conditions and under low pressure promoted by light. These reactions display a broad substrate scope with respect to the alkene and alcohol components, with alkoxycarbonylations proceeding efficiently with 1 equiv of both partners, enabling coupling of complex substrates. A successful alkoxycarbonylation was performed even in the absence of solvent, displaying a remarkably low E factor for the hydrocarbonylation process.