Novel N-coordinate half-sandwich ruthenium(II) arene complexes bearing sulfonamide fragments: Catalytic activities in the TH of acetophenone derivatives

The novel cationic N-coordinate ruthenium(II)/arene complexes (6-10) were prepared from the starting complex [RuCl2(p-cymene)](2) dimer. The structures of the [(p-cymene)RuLCl]Cl (L = N-arenesulfonyl-4,5-dimethyl-o-phenylenediamines) complexes were elucidated by FT-IR, H-1-NMR,C-13-NMR, ionic conductivity techniques, and elemental analysis methods. The 6-10 complexes were applied as catalyst in the transfer hydrogenation (TH) of ketones. The catalytic tests showed that all the complexes are moderate catalysis precursors. Especially, {[N-benzenesulfonyl-4,5-dimethyl-o-phenylenediamine]-(p-cymene)-di-chloro-ruthenium(II)} (8) and {[N-4-chlorobenzenesulfonyl-4,5-dimethyl-o-phenylenediamine]-(p-cymene)-di-chloro-ruthenium(II)} (9) compounds were found to be a good catalysts in comparison to the others giving the corresponding alcohols in a good turnover frequency value of 1534 and 1731 h(-1), respectively. (C) 2015 Elsevier B.V. All rights reserved.