56423-57-5Relevant articles and documents
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.
supporting information, p. 13630 - 13640 (2019/09/30)
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.
Purification and characterization of an NADH-dependent alcohol dehydrogenase from Candida maris for the synthesis of optically active 1-(pyridyl)ethanol derivatives
Kawano, Shigeru,Yano, Miho,Hasegawa, Junzo,Yasohara, Yoshihiko
experimental part, p. 1055 - 1060 (2012/02/03)
A novel (R)-specific alcohol dehydrogenase (AFPDH) produced by Candida maris IFO10003 was purified to homogeneity by ammonium sulfate fractionation, DEAE-Toyopearl, and Phenyl-Toyopearl, and characterized. The relative molecular mass of the native enzyme was found to be 59,900 by gel filtration, and that of the subunit was estimated to be 28,900 on SDS-polyacrylamide gel electrophoresis. These results suggest that the enzyme is a homodimer. It required NADH as a cofactor and reduced various kinds of carbonyl compounds, including ketones and aldehydes. AFPDH reduced acetylpyridine derivatives, β-keto esters, and some ketone compounds with high enantioselectivity. This is the first report of an NADH-dependent, highly enantioselective (R)-specific alcohol dehydrogenase isolated from a yeast. AFPDH is a very useful enzyme for the preparation of various kinds of chiral alcohols.
Candida viswanathii as a novel biocatalyst for stereoselective reduction of heteroaryl methyl ketones: A highly efficient enantioselective synthesis of (S)-α-(3-pyridyl)ethanol
Soni, Pankaj,Kaur, Gurmeet,Chakraborti, Asit K.,Banerjee, Uttam C.
, p. 2425 - 2428 (2007/10/03)
The enantioselective reduction of various heteroaryl methyl ketones, such as 2-, 3-, and 4-acetyl pyridines, 2-acetyl thiophene, 2-acetyl furan, and 2-acetyl pyrrole, was carried out with the resting cells of a novel yeast strain Candida viswanathii. Excellent results were obtained with acetyl pyridines. Moderate conversion took place with 2-acetyl thiophene, but no significant reduction was observed with 2-acetyl furan and 2-acetyl pyrrole. In the case of acetyl pyridines, the bioreduction was found to be sensitive toward the nature of substitution on the pyridine nucleus and the conversion followed the order 4-acetyl pyridine > 3-acetyl pyridine > 2-acetyl pyridine. Reduction of 3-acetyl pyridine with a high conversion (>98%) and excellent enantioselectivity (ee >99%) provided the biocatalytic preparation of (S)-α-(3-pyridyl)ethanol, a key intermediate of pharmacologically interesting alkaloids-akuamidine and heteroyohimidine. Finally, preparative scale reduction of 3-acetyl pyridine has been carried out with excellent yield (>85%) and almost absolute enantioselectivity (ee >99.9%).
