Iridium Complex-Catalyzed C2-Extension of Primary Alcohols with Ethanol via a Hydrogen Autotransfer Reaction.

The development of a C2-extension of primary alcohols with ethanol as the C2 source and catalysis by [Cp*IrCl2]2 (where Cp* = pentamethylcyclopentadiene) is described. This new extension system was used for a range of benzylic alcohol substrates and for aliphatic alcohols with ethanol as an alkyl reagent to generate the corresponding C2-extended linear alcohols. Mechanistic studies of the reaction by means of intermediates and deuterium labeling experiments suggest the reaction is based on hydrogen autotransfer.