Organoactinides Promote the Tishchenko Reaction: The Myth of Inactive Actinide−Alkoxo Complexes

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 Cp* 2 ThMe 2 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.