For many decades, compounds containing oxygen atoms were excluded from the actinide-catalysis field because of the high oxophilic nature of these complexes. Pursuing the conceptual question about the potential activity of actinide-oxo bonds we were surprised to find that the coupling of aromatic aldehydes catalyzed by (Cp2ThMe2)-Th-* and Th(NEtMe)(4) via thorium-alkoxide intermediates takes place in high yields to produce the corresponding esters. In this paper we present our breakthrough results including comprehensive mechanistic, deuterium labeling, kinetic, and thermodynamic studies. A plausible mechanism is presented taking into account as well the thermochemistry of the process.