7476-63-3Relevant academic research and scientific papers
One-pot method for the synthesis of 1-aryl-2-aminoalkanol derivatives from the corresponding amides or nitriles
Bobal, Pavel,Otevrel, Jan,Svestka, David
, p. 25029 - 25045 (2020/07/14)
We have identified a novel one-pot method for the synthesis of β-amino alcohols, which is based on C-H bond hydroxylation at the benzylic α-carbon atom with a subsequent nitrile or amide functional group reduction. This cascade process uses molecular oxygen as an oxidant and sodium bis(2-methoxyethoxy)aluminum hydride as a reductant. The substrate scope was examined on 30 entries and, although the respective products were provided in moderate yields only, the above simple protocol may serve as a direct and powerful entry to the sterically congested 1,2-amino alcohols that are difficult to prepare by other routes. The plausible mechanistic rationale for the observed results is given and the reaction was applied to a synthesis of a potentially bioactive target. This journal is
Chemo-enzymatic synthesis of enantiomerically pure (R)-2-naphthylmethoxyacetic acid
Kimura, Mayumi,Kuboki, Atsuhito,Sugai, Takeshi
, p. 1059 - 1068 (2007/10/03)
Enantiomerically pure (R)-2-naphthylmethoxyacetic acid (2-NMA) was synthesized from 2-naphthaldehyde via an integrated chemo-enzymatic procedure. The one-pot, successive use of SnBr2-TMSCN and AcBr worked effectively to give a racemic cyanohydrin acetate. Lipase from Burkholderia cepacia then mediated the highly enantioselective hydrolysis of the (S)-enantiomer of the racemate, leaving the (R)-acetate with an e.e. of >99.9%. The resulting product of this enzyme-catalyzed hydrolysis, an (S)-cyanohydrin, spontaneously decomposed into naphthaldehyde, the starting material of this synthetic route, which could be recycled. The hydration of nitrile to amide as well as the hydrolysis of the acetate was performed with a microorganism, Rhodococcus rhodochrous, under very mild conditions without any loss of the enantiomeric purity. The amide group was hydrolyzed with nitrosylsulfuric acid, and the product was isolated as an α-hydroxy ester. The α-hydroxyl group was methylated with diazomethane-silica gel and the final task, hydrolysis of the ester, was accomplished under conditions as mild as neutral pH with an esterase from Krebsiella oxytoca to give enantiomerically pure 2-NMA.
Enantioselective biotransformations of racemic α-substituted phenylacetonitriles and phenylacetamides using Rhodococcus sp. AJ270
Wang, Mei-Xiang,Lu, Gang,Ji, Gai-Jiao,Huang, Zhi-Tang,Meth-Cohn, Otto,Colby, John
, p. 1123 - 1135 (2007/10/03)
Rhodococcus sp. AJ270 is an efficient whole-cell system able to catalyze the stereoselective conversions of racemic α-substituted phenylacetonitriles and amides under very mild conditions into enantiopure carboxylic acids and derivatives. The nitrile hydratase involved generally has a broad substrate spectrum against phenylacetonitriles irrespective of the electronic nature of the α-substituent while the amidase is very sensitive to both the electronic and steric factors of the substituent of amides. The overall enantioselectivity of nitrile hydrolysis is mainly determined by the combination of selectivities of nitrile hydratase and of amidase, with the latter being a major contributor. The amidase has high S-enantiocontrol against amides while the nitrile hydratase exhibits low R-selectivity against nitriles. The scope and limitations of this enantioselective biotransformation process are discussed. Copyright (C) 2000 Elsevier Science Ltd.
The Chemistry of 5-Oxodihydroisoxazoles. Part 23. Photochemical and Thermal Reactions of Isoxazol-5(2H)-ones Substituted at C-3 or C-4 with Nitrogen, Oxygen or Sulfur
Khalafy, Jabbar,Prager, Rolf H.,Smith, Jason A.
, p. 518 - 536 (2007/10/03)
The photolysis of 2,3-dimethyl-4-phenoxy- and 4-thiophenoxyisoxazol-5(2H)-one in methanol has been re-examined, but no new products were isolated. Flash vacuum pyrolysis of the former gave a novel product, phenyl N-methylpropenimidate, from rearrangement of the intermediate carbene. Irradiation of the 3-hydroxy-2-phenyl-4-carboxylate gave two products which arise from the 3-hydroxy and 5-hydroxy tautomers. By contrast, the 3-hydroxy-4-acetyl isoxazolone reacted exclusively as one tautomer giving the expected loss of CO2 to form the carbene which was captured by methanol on photolysis, or underwent methyl migration and cyclisation to 3-methylazetidine-1,3-dione on pyrolysis. 3-Amino and 3-phenylamino substituted isoxazolones also gave photolysis and pyrolysis products characteristic of discrete tautomers.
The Chemistry of 5-Oxodihydroisoxales. XI; The Photolysis of 3-Hydroxy-4-phenylisoxazol-5(2H)-ones (Phenyldisic Acids)
Prager, Rolf H.,Smith, Jason A.
, p. 217 - 226 (2007/10/02)
3-Hydroxy-2-methyl-4-phenylisoxazol-5(2H)-one, 3-hydroxy-2,4-diphenylisoxazol-5(2H)-one and phenyldisic acid have been photolysed at 254 nm in hydroxylic solvents.By comparision of the respective products with those obtained from 3-methoxy-4-phenylisoxazo
Photolysis of Phenyldisic Acids: Evidence for Unique Product Formation from Discrete Tautomers
Prager, Rolf H.,Smith, Jason A.
, p. 1805 - 1806 (2007/10/02)
3-Hydroxy-2-methyl-4-phenylisoxazol-5(2H)-one exists as four tautomers, two of which are isolated and characterised; photolysis in methanol leads to formation of products identified as arising uniquely from three of the tautomers, and the 2-phenyl analogue and phenyldisic acid undergo similar photochemical reactions.
