Catalytic activity of Ru/tetrahydropyrimidinium salts system for transfer hydrogenation reactions

New 1,3-dialkyltetrahydropyrimidinium salts as NHC precursors have been synthesized and characterized. The in situ prepared three-component 1,3-dialkyltetrahydropyrimidinium salts/[RuCl2(p-cymene)](2) and KOH catalyzes quantitatively the transfer hydrogenation of ketones under mild reaction conditions in 2-propanol. Also, the molecular structure of 1,3-bis(2-methylbenzyl)-3,4,5,6-tetrahydropyrimidinium was determined using single-crystal X-ray diffraction. Ions of the title compound are linked by CH...Cl and OH...Cl hydrogen bonding interactions. The NCN bond angle (124.3(2)degrees) and CN bond lengths (1.316(3) and 1.314(3) angstrom) confirm the existence of strong resonance in this part of the molecule. Copyright (c) 2015 John Wiley & Sons, Ltd.