81702-59-2Relevant academic research and scientific papers
Structural, kinetics and mechanistic studies of transfer hydrogenation of ketones catalyzed by chiral (pyridyl)imine nickel(ii) complexes
Kumah, Robert T.,Tsaulwayo, Nokwanda,Xulu, Bheki A.,Ojwach, Stephen O.
, p. 13630 - 13640 (2019)
The chiral synthons (S-)-1-phenyl-N-(pyridine-2-yl)ethylidine)ethanamine (L1), (R-)-1phenyl-N-(pyridine-2-yl)ethylidine))ethanamine (L2) (S)-1-phenyl-N-(pyridine-2-yl methylene) ethanamine (L3), and (R)-1-phenyl-N-(pyridine-2-yl methylene) ethanamine (L4) were synthesized in good yields. Treatments of L1-L4 with NiBr2(DME) and NiCl2 precursor afforded dinuclear complexes [Ni2(L1)4-μ-Br2]NiBr4 (Ni1), [Ni2(L2)4-μ-Br2]NiBr4 (Ni2), [Ni2(L3)4-μBr2]Br2 (Ni3), [Ni2(L4)4-μ-Br2]NiBr4 (Ni4) and [Ni(L4)2Cl2] (Ni5). The identities of the compounds were established using NMR, FT-IR and EPR spectroscopy, mass spectrometry, magnetic moments, elemental analysis and single crystal X-ray crystallography. The dinuclear dibromide nickel complexes dissociate into mononuclear species in the presence of strongly coordinating solvents. Compounds Ni1-Ni5 displayed moderate catalytic activities in the asymmetric transfer hydrogenation (ATH) of ketones, but with low enantiomeric excess (ee%). Both mercury and substoichiometric poisoning tests pointed to the homogeneous nature of the active species with the partial formation of catalytically active Ni(0) nanoparticles. Low resolution mass spectrometry analyses of the intermediates supported a dihydride mechanistic pathway for the transfer of hydrogenation reactions.
Structural elucidation of chiral (imino)pyridine/phosphine palladium(II) complexes and their applications as catalysts in methoxycarbonylation of styrene
Akiri, Saphan O.,Ngcobo, Nondumiso L.,Ogweno, Aloice O.,Ojwach, Stephen O.
, (2021/06/15)
Treatment of ligands (S)-1-phenyl-N-(1-(pyridin-2-yl)ethylidene)ethanamine (L1), (R)-1-phenyl-N-(1-(pyridin-2-yl)ethylidene)ethanamine (L2), (S)-1-phenyl-N-((pyridin-2-yl)methylene)ethanamine (L3), (R)-1-phenyl-N-((pyridin-2-yl)methylene)ethanamine (L4), (S)-N-(2-(diphenylphosphino)benzylidene)-1-phenylethanamine (L5), and (R)-N-(2-(diphenylphosphino)benzylidene)-1-phenylethanamine (L6) with [Pd(COD)Cl2] afforded the respective palladium complexes [Pd(L1)Cl2] (1), [Pd(L2)Cl2] (2), [Pd(L3)Cl2] (3), [Pd(L4)Cl2] (4), [Pd(L5)Cl2] (5) and [Pd(L6)Cl2] (6) in high yields. Solid-state structures of the complexes established N^N and N^P bidentate coordination mode of the ligands to give distorted square planar geometries. Complexes 1–6 displayed moderate catalytic activities in the methoxycarbonylation of styrene, to give predominantly branched esters of up to 95%. NMR spectroscopy studies pointed to possible decomposition of the active species, via ligand dissociation.
Preparation method of chiral amine compounds
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Paragraph 0022, (2018/09/13)
The invention discloses a preparation method of chiral amine compounds. The preparation method of the chiral amine compounds specifically comprises the following steps: adding ketone compounds and chiral auxiliary (S)-a-phenylethylamine or (R)-a-phenylethylamine to an organic solvent to prepare an imine intermediate under the action of a large-steric-hindrance boron catalyst and a water removing agent; adding a reducing agent to the imine intermediate without separation and purification, and preparing the chiral amine compounds with a one-pot method. By calculation, the product yield is 81%-96%, and the highest de value can reach 99%. Compared with the prior art, the use amount of the large-steric-hindrance boron catalyst in the method can be reduced to 0.1 mol%, use of the equivalent metal catalyst is avoided from the source, and the method has the characteristics of being simple to operate, mild in reaction condition, wide in substrate applicability, environmental friendly and the like, and has better application value and potential economic and social benefits.
Zinc complexes bearing N,N′-bidentate entiopure ligands: Synthesis, structure and catalytic activity toward ring opening polymerisation of rac-lactide
Nayab, Saira,Lee, Hyosun,Jeong, Jong Hwa
experimental part, p. 55 - 62 (2012/09/22)
Dichloro zinc complexes with (S)-1-phenyl-N-[(S)-1-(pyridin-2-yl)ethyl] ethanamine (PMMA) and (S)-1-(6-methylpyridin-2-yl)-N-[(S)-1-phenylethyl] ethanamine (MPMMA) were prepared and characterised by X-ray diffraction. The catalytic activity of the dimethyl complexes, generated in situ, was high in the ring opening polymerization of rac-lactide. Specifically, the dimethyl derivative of (PMMA)ZnCl2 yielded a highly stereocontrolled polylactide with Pr = 0.84.
ASYMMETRISCHE KATALYSEN. XXIV. CROSS-COUPLING VON 1-PHENYLETHYLGRIGNARD UND VINYLBROMID MIT Ni-KATALYSATOREN OPTISCH AKTIVER P/N-LIGANDEN
Brunner, H.,Li, Weichang,Weber, H.
, p. 359 - 364 (2007/10/02)
Sixteen new N/N, P/N, and P/P chelate ligands, together with NiCl2, were used as in-situ catalysts for the enantioselective cross-coupling of 1-phenylethylgrignard and vinylbromide.The N/N ligands give no optical yield in the formation of the product 3-ph
