Cobalt-Catalyzed Decarboxylative Methylation and Ethylation of Aliphatic N-(Acyloxy)phthalimides with Organoaluminum Reagents

A cobalt-catalyzed decarboxylative methylation of aliphatic redox-active esters [N-(acyloxy)phthalimides; RAEs] with trimethylaluminum under mild conditions was developed, providing a method for transforming a carboxylate group into a methyl group without redox fluctuation. Primary and secondary RAEs were both amenable substrates, whereas a tertiary RAE delivered an elimination product. Triethylaluminum was also used to deliver a decarboxylative ethylation product.