Phenyl substituted indenylphosphine ruthenium complexes as catalysts for dehydrogenation of alcohols†
Jia Yuan,Yue Sun,Guang-Ao Yu,Cui Zhao,Neng-Fang She,Shu-Lan Mao,Peng-Shou Huang,Zhi-Jun Han,Jun Yin,Sheng-Hua Liu
Dalton Transactions Pub Date : 06/22/2012 00:00:00 , DOI:10.1039/C2DT30499F
Abstract

Thermal treatment of (1H-inden-3-yl)dicyclohexylphosphinium tetrafluoroborate (1) and (3-mesityl-1H-inden-3-yl)dicyclohexylphosphinium tetrafluoroborate (3) with tBuONa followed by [(η6-cymene)RuCl2)]2 in methanol gave the adduct {(η6-cymene)RuCl2[(1H-inden-3-yl)PCy2]} (6) and {(η6-cymene)RuCl2[(3-mesityl-1H-inden-3-yl)PCy2]} (7), respectively. Thermal treatment of (2-phenyl-1H-inden-3-yl)dicyclohexylphosphinium tetrafluoroborate (4) with tBuONa followed by [(η6-cymene)RuCl2)]2 or RuCl3·3H2O in methanol gave {Ru[κ(P):(η6-2-phenyl-1H-inden-3-yl)PCy2]Cl2} (8). Whereas (2-mesityl-1H-inden-3-yl)dicyclohexylphosphine (5) reacted with [(η6-cymene)RuCl2)]2 (in toluene) or RuCl3·3H2O (in ethanol) to afford {Ru[κ(P):(η6-2-mesityl-1H-inden-3-yl)PCy2]Cl2} (9). The molecular structures of complexes 6, 8 and 9 have been determined by single-crystal X-ray diffraction analysis. In addition, complexes 8 and 9 have been found to catalyze the acceptorless dehydrogenation of alcohols in toluene. 9 displayed high activity and different substrates, including cyclic and linear alcohols, were efficiently oxidized to ketones by using 2.0 mol% of catalyst.

Graphical abstract: Phenyl substituted indenylphosphine ruthenium complexes as catalysts for dehydrogenation of alcohols