Synthesis and characterization of ruthenium compounds incorporating keto-amine ligands. The applications of catalytic transfer hydrogenation and cancer cell inhibition

A series of keto-amine bidentate precursors 1–5, OCCH₃CHCCH₃NHR (where 1, R = C₆H₃-2,6-ⁱPr₂; 2, R = C₆H₂-2,4,6-Me₃; 3, R = C₆H₄-2-^tBu; 4, R = C₆H₄-2-OMe; 5, R = C₆H₄-2-OMe-5-Me) were synthesized and combined with [Ru(ɳ⁶-p-cymene)Cl₂]₂ to generate the monomeric arene-Ru derivatives, [Ru(ɳ⁶-p-cymene)(OCCH₃CHCCH₃NR)Cl] (where 6, R = C₆H₃-2,6-ⁱPr₂; 7, R = C₆H₂-2,4,6-Me₃; 8, R = C₆H₄-2-^tBu; 9, R = C₆H₄-2-OMe; 10, R = C₆H₄-2-OMe-5-Me) in moderate yield. The ruthenium derivatives effectively catalyzed the conversion rate in transfer hydrogenation of substituted acetophenone. The molecular structures of 2, 6–10 were determined by single crystal X-ray diffractometry in the solid state, revealing a four-coordination environment around the Ru atom. The potential anti-cancer activity of ruthenium derivatives against human hormone-refractory metastatic prostate cancer (HRMPC) cell lines was also studied.