Turkish Journal of Chemistry, Vol.40, No.2, 296-304, 2016
The role of N-heterocyclic carbene substituents on ruthenium(II) complexes in the catalytic transfer hydrogenation of acetophenone
The novel ruthenium(II) complexes [RuCl2 (NHC)(p-cymene)], 3a e, containing 1-alkyl-3-benzylimidazol2-ylidene ligands were prepared. All synthesized compounds were characterized by NMR spectroscopy and elemental analyses. Ru(II)-NHC complexes were tested as catalysts for the transfer hydrogenation of acetophenone, showing modest to high activity in this reaction. The results revealed that efficiencies depend on the substituents of the benzene ring of the benzyl on the N atom of the NHC ring.
Keywords:N-heterocyclic carbene ligands;substituent effect;transfer hydrogenation;ruthenium complexes;silver-N-heterocyclic carbene complexes