Functionalization of spᶟ-Hybridized Carbon Centers through Carbon-Carbon σ Bond Cleavage Methods

Abstract

Methods for the modification and functionalization of spᶟ-hybridized carbon centers via cleavage of unstrained carbon-carbon σ bonds are proposed. The bond breaking/forming reactions are promoted by Lewis acids and transition metals, in which Meldrum's acid and 5-methyl Meldrum's acid act as leaving groups. Under mild reaction conditions and relatively short reaction times, modification of quaternary and tertiary benzylic spᶟ-hybridized carbon centers are achieved. Both methodologies show broad scope in terms of substrates and proceed in good to excellent yields. In addition, insights into the hydrogenolysis and substitution mechanisms have been obtained and are discussed.