32345-60-1Relevant articles and documents
Synthetic studies of 7-oxygenated aporphine alkaloids: Preparation of (-)-oliveroline, (-)-nornuciferidine, and derivatives
Ku, Angela F.,Cuny, Gregory D.
, p. 1134 - 1137 (2015)
7-Oxygenated aporphines 1-6 possessing anti-configurations have previously been reported. In order to explore their bioactivities, a synthesis was established by utilizing a diastereoselective reductive acid-mediated cyclization followed by palladium-catalyzed ortho-arylations. Moderate XPhos precatalyst loading (10 mol %) and short reaction times (30 min) were sufficient to mediate the arylations. Alkaloids 1-5 were successfully prepared, while (-)-artabonatine A was revised to syn-isomer 30. Consequently, (-)-artabonatine E likely also has a syn-configuration (31).
Application of the redox system of Nocardia corallina B-276 in the enantioselective biotransformation of ketones and alcohols
Alvarez, Norberto Manjarrez,Pérez Méndez, Herminia I.,Oba, Aida Solís,Cabello, Lucía Ortega,Lara Carvajal, María T.,Valencia Ledezma, Omar E.,Martínez-Casares, Rubria M.
, p. 279 - 290 (2020/06/01)
The aim of this research was to evaluate the redox system of Nocardia corallina B-276 in the biotransformation of 1-phenyl-1-propanone (1a), 2-hydroxy-1-phenylethanone (2a) and methyl (2-chlorophenyl)(oxo)acetate (3a) into 1-phenylpropan-1-ol (1b), 1-phenyl-1,2-ethanediol (2b) and methyl (2-chlorophenyl)(hydroxy)acetate (3b). The biomass of N. corallina was obtained in a liquid medium with an initial pH of 8.50, but the pH changed during the 96 h of the culture media, the final pH was between 4.74 and 7.62. The N. corallina biomass biocatalyzed the enantioselective reduction of 1a–3a to the corresponding alcohols. Whereas, during the process of oxidation of the rac-alcohols 1b–3b, 1b was oxidized in enantioselective way, the oxidation of 2b was not selective, but 3b was biotransformed mainly to (R)-3b. These results are indicative that N. corallina produced reductases and oxidases, whereby the biocatalytic activity was influenced by the final pH of the culture media, the reaction time and structure of the substrate.
Identification of Novel 1-O-Substituted Aporphine Analogues as Potent 5-HT2C Receptor Agonists
Li, Wanwan,Mao, Qi,Shui, Wenqing,Tian, Sheng,Ye, Na,Zhang, Bingjie
, p. 549 - 559 (2020/03/06)
The 5-HT2C receptor has emerged as a promising target in the treatment of a variety of central nervous system disorders. We have first identified aporphines as a new class of 5-HT2C receptor agonists. Structure-activity relationship
Calcium(II)-mediated resolution of methyl o-chloromandelate with chiral O,O′-dibenzoyltartaric acid in preparative scale
Xu, Hong-Wu,Wu, Li-Huan,Ren, Qiang,Liu, Cui-Yu,Yan, Guan-Qing
, p. 19 - 22 (2018/12/11)
We report here the coordination-mediated resolution of methyl o-chloromandelate, which is a key intermediate for clopidogrel, in preparative scale. The reaction of CaO, optically pure (2R, 3R)-O,O′-dibenzoyltartaric acid, and methyl o-chloromandelate in ethanol solution afforded a mixed-ligands calcium(II) complex that was further purified by stirring of the crystals in hot methanol. Methyl (R)-o-chloromandelate was obtained in good enantiomeric excess value (>99.5%) and yield (71%) by treatment of the complex with acid. At the same time, (2R, 3R)-O,O′-dibenzoyltartaric acid was recovered in 72% yield. In addition, methyl (S)-o-chloromandelate was obtained in good enantiomeric excess value (>99.5%) and yield (73%) by recovery from the mother liquor and resolution with the same procedure for methyl (R)-o-chloromandelate, except that (2S, 3S)-O,O′-dibenzoyltartaric acid was used as the resolving reagent.
Improved apparent enantioselectivity of a hydrolase by sequential hydrolysis and racemization
Gu, Jiali,Ye, Lidan,Guo, Fei,Lv, Xiaomei,Lu, Wenqiang,Yu, Hongwei
supporting information, p. 1489 - 1491 (2015/03/14)
Further improvement of the enantioselectivity of hydrolases with moderate enantioselectivity is of important significance to fulfill the requirement in industrial application. Herein, a strategy based on sequential hydrolysis and racemization was adopted, using esterase BioH from Escherichia coli as an example. After coupling with a mandelate racemase, the E value of esterase BioH toward methyl (S)-o-chloromandelate was enhanced from 73 to 162, demonstrating the effectiveness of this strategy.
Efficient reduction of ethyl 2-oxo-4-phenylbutyrate at 620 ?l -1 by a bacterial reductase with broad substrate spectrum
Ni, Yan,Li, Chun-Xiu,Zhang, Jie,Shen, Nai-Dong,Bornscheuer, Uwe T.,Xu, Jian-He
supporting information; experimental part, p. 1213 - 1217 (2011/07/09)
A β-ketoacyl-ACP reductase (FabG) gene from Bacillus sp. ECU0013 was heterologously overexpressed in Escherichia coli and the encoded protein was purified to homogeneity. The recombinant reductase could reduce a broad spectrum of prochiral ketones including aromatic ketones and keto esters and showed the highest activity in the asymmetric reduction of ethyl 2-oxo-4-phenylbutyrate (OPBE). Using E. coli cells coexpressing both FabG and glucose dehydrogenase (GDH) genes, as much as 620 ?L-1 of OPBE was almost stoichiometrically converted to ethyl (S)-2-hydroxy-4-phenylbutyrate [(S)-HPBE] with excellent (>99%) enantiomeric excess. More importantly, the process could be performed smoothly without external addition of an expensive cofactor as usually done and could be scaled up very easily. All these positive features demonstrate the applicability of this reductase for the large-scale production of optically active α-hydroxy acids/esters.
Asymmetric reduction of α-keto esters with Thermus thermophilus NADH-dependent carbonyl reductase using glucose dehydrogenase and alcohol dehydrogenase for cofactor regeneration
Pennacchio, Angela,Giordano, Assunta,Rossi, Mose,Raia, Carlo A.
supporting information; experimental part, p. 4361 - 4366 (2011/10/08)
The enantioselective synthesis of methyl (R)-mandelate and methyl (R)-o-chloromandelate was investigated using an NADH-dependent carbonyl reductase from Thermus thermophilus (TtADH) and, separately, archaeal glucose dehydrogenase and Bacillus stearothermo
Simply air: Vanadium-catalyzed oxidative kinetic resolution of methyl o-chloromandelate by ambient air
Yin, Lu,Jia, Xian,Li, Xing Shu,Chan, Albert S.C.
experimental part, p. 774 - 777 (2011/11/12)
Vanadium-catalyzed oxidative kinetic resolution (OKR) of methyl o-chloromandelate 2a, key intermediate of the well-known oral antiplatelet agent (S)-clopidogrel, was achieved by ambient air for the first time. The air oxidation system, which was composed of vanadium and tridentate Schiff base ligands derived from amino alcohols and salicylaldehyde derivatives, afforded an efficient and economic approach to the target intermediate with high enantioselectivities (>99% ee).
Ru-catalyzed enantioselective preparation of methyl (R)-o-chloromandelate and its application in the synthesis of (S)-Clopidogrel
Yin, Lu,Shan, Wenjun,Jia, Xian,Li, Xingshu,Chan, Albert S.C.
experimental part, p. 2092 - 2095 (2009/10/31)
The preparation of methyl (R)-o-chloromandelate via Ru-catalyzed asymmetric hydrogenation and transfer hydrogenation was investigated. With Ru-(R,R)-2,4,6-triisopropyl C6H2SO2-DPEN as the catalyst and HCOOH-Et3N azeotrope as the hydrogen donor, up to 92% ee was obtained in an optional condition. The synthesis of (S)-Clopidogrel was also studied.
A rapid and green approach to chiral α-hydroxy esters: asymmetric transfer hydrogenation (ATH) of α-keto esters in water by use of surfactants
Yin, Lu,Jia, Xian,Li, Xingshu,Chan, Albert S.C.
experimental part, p. 2033 - 2037 (2010/01/16)
A series of α-hydroxy esters were rapidly prepared (1.5 h) from α-keto esters via asymmetric transfer hydrogenation (ATH) in water by the use of surfactants for the first time. This green method, catalyzed by a water-soluble and recyclable Ru(II) complex, gave moderate to high enantioselectivities (up to 99.7% ee) with DTAB as an additive and HCOONa as the hydrogen source.
