Efficient acceptorless dehydrogenation of secondary alcohols to ketones mediated by a PNN-Ru(ii) catalyst. Issue 8 (5th April 2017)

• Record Type: Journal Article
• Authors: Wang, Zheng; Pan, Bing; Liu, Qingbin; Yue, Erlin; Solan, Gregory A.; Ma, Yanping; Sun, Wen-Hua
• Is Part Of: Catalysis science & technology. Volume 7:Issue 8(2017)
• Page Start: 1654
• Page End: 1661
• Publication Date: 2017-04-05
• Subjects: Catalysis -- Periodicals; 541.395
• DOI: 10.1039/c7cy00342k
• Languages: English
• ISSNs: 2044-4753

Abstract

Abstract : The ruthenium(ii ) complex, [ fac -PNH N]RuCl2 (PPh3 ) (C ), in combination with t -BuOK proved an effective and versatile catalyst allowing aromatic-, aliphatic- and cycloalkyl-containing alcohols to be efficiently converted to their corresponding ketones with high values of TON achievable. Abstract : Four types of ruthenium(ii ) complexes, [ fac -PNN]RuH(PPh3 )(CO) (A ), [ fac -PNH N]RuH(η 1 -BH4 )(CO) (B ), [ fac -PNH N]RuCl2 (PPh3 ) (C ) and [ fac -PNH N]RuH(η 1 -BH4 )(PPh3 ) (D ) (where PNH N and PNN are N -(2-(diphenylphosphino)ethyl)-5, 6, 7, 8-tetrahydroquinoline-8-amine and its deprotonated derivative), have been synthesized and assessed as catalysts for the acceptorless dehydrogenation of secondary alcohols to afford ketones. It was found thatC, in combination with t -BuOK, proved the most effective and versatile catalyst allowing aromatic-, aliphatic- and cycloalkyl-containing alcohols to be efficiently converted to their corresponding ketones with particularly high values of TON achievable. Furthermore, the mechanism for this PNN-Ru mediated process been proposed on the basis of a number of intermediates that have been characterized by EI-MS and NMR spectroscopy. These catalysts show great potential for applications in atom-economic synthesis as well as in the development of organic hydride-based hydrogen storage systems.