Chemoselective Access to γ-Ketoesters with Stereogenic Quaternary α-Center or γ-Keto Nitriles by Aerobic Reaction of α-Cyanoesters and Styrenes

Chemoselective access to either γ-ketoesters with a quaternary all-carbon α-stereogenic center or γ-keto nitriles is described by copper-catalyzed aerobic reaction of styrenes with α-cyanoesters. Formal oxo-enolation or oxo-cyanomethylation of styrenes is achieved via a sequence of addition of enolate (or cyanomethyl) radical to olefin and oxidation of the resulting radical adduct. This method starts from abundant and cheap feedstock under aerobic conditions, without any prefunctionalization or the production of stoichiometric metal salts waste, making it very attractive for practical use.