Palladium–(N‐Heterocyclic Carbene) Hydrogenation Catalysts

Abstract

Low-valent palladium compounds with N-heterocyclic carbenes (NHCs) formed from [Pd(NHC)(η2-alkene)2] (see example) are amazingly selective catalysts for the hydrogenation of several alkynes to Z alkenes. One such complex, [Pd{1,3-(2,6-diethylphenyl)imidazol-2-ylidene}], has been employed for the selective (95 %) hydrogenation of 1-phenyl-1-propyne to (Z)-1-phenyl-1-propene.