916165-79-2Relevant academic research and scientific papers
Mechanism of hydrogen transfer to imines from a hydroxycyclopentadienyl ruthenium hydride. Support for a stepwise mechanism
Samec, Joseph S. M.,Ell, Alida H.,Baeckvall, Jan-E.
, p. 2748 - 2749 (2004)
The negligible double kinetic deuterium isotope effect (k HH/kDD = 1.05) in the reaction where [2,3,4,5-Ph 4(η5-C4COH)Ru(CO)2H (2) transfers a hydride and a proton to N-phenyl-[1-(4-methoxyphenyl)ethylidene] amine (4) indicates that no bond to hydrogen is broken or formed in the rate-determining step.
Mechanistic study of hydrogen transfer to imines from a hydroxycyclopentadienyl ruthenium hydride. Experimental support for a mechanism involving coordination of imine to ruthenium prior to hydrogen transfer
Samec, Joseph S. M.,Ell, Alida H.,Aberg, Jenny B.,Privalov, Timofei,Eriksson, Lars,Baeckvall, Jan-E.
, p. 14293 - 14305 (2008/03/13)
Reaction of [2,3,4,5-Ph4(η5-C4COH) Ru(CO)2H] (2) with different imines afforded ruthenium amine complexes at low temperatures. At higher temperatures in the presence of 2, the complexes decomposed to give [RUsu
Isomerization and deuterium scrambling evidence for a change in the rate-limiting step during imine hydrogenation by Shvo's hydroxycyclopentadienyl ruthenium hydride
Casey, Charles P.,Johnson, Jeffrey B.
, p. 1883 - 1894 (2007/10/03)
Hydroxycyclopentadienyl ruthenium hydride 5 efficiently reduces imines below room temperature. Better donor substituents on nitrogen give rise to faster rates and a shift of the rate-determining step from hydrogen transfer to amine coordination. Reduction of electron-deficient N- benzilidenepentafluoroaniline (8) at 11°C resulted in free amine and kinetic isotope effects of kOH/kOD = 1.61 ± 0.08, k RuH/kRuD = 2.05 ± 0.08, and kRuHOH/ kRuDOD = 3.32 ± 0.14, indicative of rate-limiting concerted hydrogen transfer, a mechanism analogous to that proposed for aldehyde and ketone reduction. Reduction of electron-rich N-alkyl-substituted imine, N-isopropyl-(4-methyl)benzilidene amine (9), was accompanied by facile imine isomerization and scrambling of deuterium labels from reduction with 5-RuDOH into the N-alkyl substituent of both the amine complex and into the recovered imine. Inverse equilibrium isotope effects were observed in the reduction of N-benzilidene-tert-butylamine (11) at -48°C (kOH/kOD = 0.89 ± 0.06, kRuH/kRuD = 0.64 ± 0.05, and kRuHOH/kRuDOD = 0.56 ± 0.05). These results are consistent with a mechanism involving reversible hydrogen transfer followed by rate-limiting amine coordination.
