17480-69-2Relevant articles and documents
Iridium(I)-Catalyzed Asymmetric Hydrogenation of Prochiral Imines; Protic Amines as Catalyst Improvers
Tani, Kazuhide,Onouchi, Jun-ichiro,Yamagata, Tsuneaki,Kataoka, Yasutaka
, p. 955 - 956 (1995)
A catalytic system, Ir(I)-BINAP-protic amine, was found to be effective for asymmetric hydrogenation of imines and the highest enatioselectivity of 90percent ee has been attained for the hydrogenation of the cyclic imine, 2-phenyl-3,4,5,6-tetrahydropyridine.
Application of phosphine-oxazoline ligands in Ir-catalyzed asymmetric hydrogenation of acyclic aromatic N-arylimines
Triforiova, Anna,Diesen, Jarle S.,Chapman, Christopher J.,Andersson, Pher G.
, p. 3825 - 3827 (2004)
(Chemical Equation Presented) A new class of chiral phosphine-oxazoline ligands have been developed. Chiral Ir complexes prepared from these ligands induced high enantioselectivities (66-90% ee) when applied to the asymmetric hydrogenation of acyclic aromatic N-arylimines.
A practical synthesis of enantiomerically pure N-benzyl-α-methyl benzylamine
Huckabee, Brian K.,Lin, Sechoing,Smith, Traci L.,Stuk, Timothy L.
, p. 594 - 595 (2000)
Optically pure (R)- and (S)N-benzyl-α-methyl benzylamine have been prepared on pilot plant scale from benzaldehyde and α-phenyl-ethylamine via palladium-catalyzed hydrogenation of the intermediate (R)-benzylidene-(1-phenylethyl)amine.
Phosphines versus phosphinites as ligands in the rhodium catalyzed asymmetric hydrogenation of imines: A systematic study
Tararov, Vitali I.,Kadyrov, Renat,Riermeier, Thomas H.,Holz, Jens,Boerner, Armin
, p. 4009 - 4015 (1999)
The asymmetric hydrogenation of N-(1-phenylethylidene)benzylamine with a range of rhodium(I)-diphosphine and diphosphinite catalysts is studied. The reaction is strongly sensitive to the size of the metal chelate. Complexes based on five- and six-membered chelates or electron-rich alkylphosphines gave poor or moderate conversions. The reactivity of diphosphine catalysts could be increased by the addition of p-toluenesulfonic acid. Unexpectedly, Rh-complexes based on chiral diphosphinites and a diphosphite also rapidly converted the substrate to the desired amine. Highest efficiency was observed with a rhodium(I) complex with (R,R)-1,2-cyclohexanol-bisdiphenylphosphinite [(R,R)-bdpch] as chiral ligand. Without any additive complete hydrogenation of the imine was achieved within 5 h. The product was produced in an enantioselectivity of 71%.
Iridium-Catalyzed Enantioselective Hydrogenation of Imines with Xylose Diphosphite and Diphosphinite Ligands
Guiu, Ester,Mu?oz, Bianca,Castillón, Sergio,Claver, Carmen
, p. 169 - 171 (2003)
Iridium complexes incorporating xylose diphosphinite 1 and diphosphite 2, 3 ligands as source of chirality are active catalysts for the hydrogenation of imines providing moderate ee. The enantioselectivity depends on the fine tuning of the structural parameters of the ligand and on the effect of additives.
Asymmetric thermal transformation, a new way to enantiopure biphenyl- bridged titanocene and zirconocene complexes: Efficient catalysts for asymmetric imine hydrogenation
Ringwald, Markus,Stürmer, Rainer,Brintzinger, Hans H.
, p. 1524 - 1527 (1999)
Enantiopure biphenyl-bridged titanocene and zirconocene complexes were obtained, by an asymmetric thermal transformation of the binaphthol complexes formed from the metallocene racemates and subsequent transformation to the corresponding dichlorides, in practically quantitative yields. Increased rates of this transformation in the presence of O2 gas or TEMPO indicate a radical reaction mechanism. The biphenyl-bridged titanocene enantiomers give rise to an efficient asymmetric catalysis for the hydrogenation of cyclic and noncyclic imines.
Efficient enantioselective hydrogenation of arylimines using aminophosphine-oxazoline iridium catalysts
Blanc, Catherine,Agbossou-Niedercorn, Francine,Nowogrocki, Guy
, p. 2159 - 2163 (2004)
The preparation and characterization of cationic iridium complexes bearing chiral aminophosphine-oxazoline auxiliaries of general formula [Ir(COD)L*]X [X: PF6 and B(ArF)4] is reported. These complexes have been applied to the asymmetric hydrogenation of two imines: N-(phenylethylidene)aniline S1 and N-(phenylethylidene)benzylamine S2 providing the corresponding chiral amines in up to 90% and 82% ee, respectively.
Application of Transmetalation to the Synthesis of Planar Chiral and Chiral-at-Metal Iridacycles
Arthurs, Ross A.,Hughes, David L.,Horton, Peter N.,Coles, Simon J.,Richards, Christopher J.
, p. 1099 - 1107 (2019)
Diastereoselective lithiation of (S)-2-ferrocenyl-4-(1-methylethyl)oxazoline, followed by addition of HgCl2, resulted in the formation by transmetalation of an (S,Sp)-configured mercury substituted complex. Addition to this of [Cp?IrCl2]2 and tetrabutylammonium chloride resulted in a second transmetalation reaction and formation of an (S,Sp,RIr)-configured chloride-substituted half-sandwich iridacycle as exclusively a single diastereoisomer. By reversing the lithiation diastereoselectivity by use of a deuterium blocking group, an alternative (S,Rp,SIr)-configured iridacycle was synthesized similarly. Use of (R)-Ugi's amine as substrate in the lithiation/double transmetalation sequence gave an (R,Sp,SIr)-configured half-sandwich iridacycle, complexes of this type being previously unavailable by direct cycloiridation. Lithium to gold transmetalation was also demonstrated with the synthesis of an (S,Sp)-configured Au(I) ferrocenyloxazoline derivative. Use of the (S,Rp,SIr)-iridacycle as a catalyst for the formation of a chiral product by reductive amination with azeotropic HCO2H/NEt3 resulted in a racemate.
A novel ruthenium-catalyzed amination of primary and secondary alcohols
Tillack, Annegret,Hollmann, Dirk,Michalik, Dirk,Beller, Matthias
, p. 8881 - 8885 (2006)
An improved method for the N-alkylation of primary amines with primary and secondary alcohols has been developed. Novel, effective catalyst systems, for example, Ru3(CO)12 combined with tri-o-tolylphosphine or n-butyl-di-1-adamantylphosphine, allow for aminations in a good yield under comparatively mild conditions.
Mechanistic investigation on the hydrogenation of imines by [p-(Me 2CH)C6H4Me]RuH(NH2CHPhCHPhNSO 2C6H4-p-CH3). Experimental support for an ionic pathway
Aberg, Jenny B.,Samec, Joseph S. M.,Baeckvall, Jan-E.
, p. 2771 - 2773 (2006)
The need for acidic activation in the stoichiometric hydrogenation of benzyl-[1-phenyl-ethylidene]-amine (6a) or [1-(4-methoxy-phenyl)-ethylidene]- methyl-amine (6b) by Noyori's catalyst [p-(Me2CH)C6H 4Me]RuH(NH2CHPhCHPhNSO2C6H 4-p-CH3) (2) is inconsistent with the proposed concerted mechanism and supports an ionic mechanism. The Royal Society of Chemistry 2006.