Expedient Synthesis of Ketones via N-Heterocyclic Carbene/ Nickel-Catalyzed Redox-Economical Coupling of Alcohols and Alkynest

Summary of main observation and conclusion An A/-heterocyclic carbene/nickel-catalyzed direct coupling of alcohols and internal alkynes to form a-branched ketones has been developed.This methodology provides a new approach to afford branched ketones,which are difficult to access through the hydroacylation of simple internal alkenes with aldehydes.This redox-neutral and redox-economical coupling is free from any oxidative or reductive additives as well as stoichiometric byproducts.These reactions convert both benzylic and aliphatic alcohols and alkynes,two basic feedstock chemicals,into various a-branched ketones in a single chemical step.