Protonated Aminocyclopentadienyl Ruthenium Hydride Reduction of Benzaldehyde and the Conversion of the Resulting Ruthenium Triflate to a Ruthenium Hydride with H<sub>2</sub> and Base
作者:Charles P. Casey、Thomas E. Vos、Steven W. Singer、Ilia A. Guzei
DOI:10.1021/om020507d
日期:2002.11.1
Reaction of N-phenyl-2,5-dimethyl-3,4-diphenylcyclopenta-2,4-dienimine (6) with Ru3CO12 formed two isomers of [2,5-Me-2-3,4-Ph-2(eta(5) -C4CNHPh)]Ru(CO)(mu-CO)}(2) (8-trans and 8-cis). Photolysis of 8 under a H-2 atmosphere led to the formation of the aminocyclopentadienyl ruthenium hydride [2,5-Me-2-3,4-Ph-2(eta(5)-C4CNHPh)]Ru(CO)(2)H (9-H). 9-H reduced benzaldehyde slowly at 75 degreesC to give benzyl alcohol and 8. Protonation of 9-H with triflic acid produced [2,5-Me-2-3,4-Ph-2(eta(5)-C4CNH2Ph)]Ru(CO)(2)H}OTf (11-H), which reacted rapidly with benzaldehyde at -80 degreesC to give benzyl alcohol and [2,5-Me-2-3,4-Ph-2(eta5-C4CNHPh)]Ru(CO)(2)OTf(9-OTf). Reaction of 9-OTf with H2 and base led to the re-formation of 9-H. These reactions provide the transformations required for a catalytic cycle for hydrogenation of aldehydes.