Ionic [Ru] complex with recyclability by electro-adsorption for efficient catalytic transfer hydrogenation of aryl ketones

The efficient reuse of homogeneous catalyst is important. Cation complex of [Ru(η⁶-p-cymene)(PPh₃)(CH₃CN) Cl]PF₆ with different ligands was synthesized and characterized by infrared spectroscopy (IR), ¹H-, ¹³C- and ³¹P-nuclear magnetic resonance spectroscopy (¹H-, ¹³C- and ³¹P-NMR), element analysis (EA), and high resolution mass spectrometry (HR-MS). The complex was used as a catalyst for the hydrogen transfer reduction of carbonyl for the first time, presenting an excellent catalytic performance of 89%–98% conversion of acetophenone and its derivatives. The catalyst may be efficiently reused by the electro-adsorption of 10 times to one catalyst recovery. The cation [Ru] complex presented advantages of both homogeneous and heterogeneous catalysts.