Chemoselective transfer hydrogenation of nitroarenes, ketones and aldehydes using acylthiourea based Ru(II) (p-cymene) complexes as pre-catalysts

Publication date: Available online 11 August 2018Source: Journal of Organometallic ChemistryAuthor(s): Pushpanathan N. Sathishkumar, Neethi Raveendran, Nattamai S.P. Bhuvanesh, Ramasamy KarvembuAbstractA new series of Ru(II) (η6-p-cymene) complexes (1–5) was synthesized from pyridine based acylthiourea ligands (L1-L5) and [Ru (η6-p-cymene)Cl2]2. All the ligands and complexes were well characterized by UV–Visible, FT-IR, mass and 1H & 13C NMR spectroscopic techniques. The molecular structures of the ligands (L1, L2, L4, L5) and complex 1 were confirmed using single crystal X-ray diffraction study. The Ru(II) (η6-p-cymene) complexes (1–5) were proved to be efficient precatalysts for the transfer hydrogenation of carbonyl compounds and nitroarenes in the presence of 2-propanol as a hydrogen donor and KOH as a base. The catalytic transfer hydrogenation reactions were chemoselective towards the nitro group in presence of carbonyl group, which is a rare scenario in homogeneous catalysis. The catalyst was compatible with broad range of substrates which include conversion of furfural, quinone and many heterocycles. The catalytic reactions exhibited very high conversions (upto 100%) and excellent yields (upto 99%). Turn Over Number (TON) was found upto 990.Graphical abstract

Source: Journal of Organometallic Chemistry - August 12, 2018 Category: Chemistry Source Type: research