118205-96-2Relevant academic research and scientific papers
Stereoselective Hydrolysis of Epoxides by reVrEH3, a Novel Vigna radiata Epoxide Hydrolase with High Enantioselectivity or High and Complementary Regioselectivity
Hu, Die,Tang, Cunduo,Li, Chuang,Kan, Tingting,Shi, Xiaoling,Feng, Lei,Wu, Minchen
, p. 9861 - 9870 (2017)
To provide more options for the stereoselective hydrolysis of epoxides, an epoxide hydrolase (VrEH3) gene from Vigna radiata was cloned and expressed in Escherichia coli. Recombinant VrEH3 displayed the maximum activity at pH 7.0 and 45 °C and high stability at pH 4.5-7.5 and 55 °C. Notably, reVrEH3 exhibited high and complementary regioselectivity toward styrene oxides 1a-3a and high enantioselectivity (E = 48.7) toward o-cresyl glycidyl ether 9a. To elucidate these interesting phenomena, the interactions of the three-dimensional structure between VrEH3 and enantiomers of 1a and 9a were analyzed by molecular docking simulation. Using E. coli/vreh3 whole cells, gram-scale preparations of (R)-1b and (R)-9a were performed by enantioconvergent hydrolysis of 100 mM rac-1a and kinetic resolution of 200 mM rac-9a in the buffer-free water system at 25 °C. These afforded (R)-1b with >99% eep and 78.7% overall yield after recrystallization and (R)-9a with >99% ees, 38.7% overall yield, and 12.7 g/L/h space-time yield.
Kinetic Resolution of rac-3-(2-Methylphenoxy)propane-1,2-diol (Mephenesin) by Sequential Lipase-Catalyzed Transesterification
Theil, Fritz,Ballschuh, Sibylle,Kunath, Annamarie,Schick, Hans
, p. 1031 - 1034 (1991)
The kinetic resolution of rac-3-(2-methylphenoxy)propane-1,2-diol (rac-1, Mephenesin) by sequential lipase-catalyzed transesterification with vinyl acetate in tetrahydrofuran/triethylamine in the presence of lipase Amano PS is described.
A Practical Synthetic Route to Enantiopure 3-Aryloxy-1,2-propanediols from Chiral Glycidol
Chen, Jian,Shum, Wilfred
, p. 2379 - 2380 (1995)
Chiral 3-aryloxy-1,2-propanediols of >98percent ee can be obtained in high yield by the nucleophilic addition of substituted phenols to chiral glycidol in the presence of triethylamine catalyst followed by recrystallization in absolute ethanol.Several enantiopure compounds of pharmaceutical significance are presented as examples.
Highly regio- and enantio-selective hydrolysis of two racemic epoxides by GmEH3, a novel epoxide hydrolase from Glycine max
Zhang, Chen,Li, Chuang,Zhu, Xiu-xiu,Liu, You-yi,Zhao, Jun,Wu, Min-chen
, p. 2795 - 2803 (2020)
A novel epoxide hydrolase from Glycine max, designated GmEH3, was excavated based on the computer-aided analysis. Then, gmeh3, a GmEH3-encoding gene, was cloned and successfully expressed in E. coli Rosetta(DE3). Among the ten investigated rac-epoxides, GmEH3 possessed the highest and best complementary regioselectivities (regioselectivity coefficients, αS = 93.7% and βR = 97.2%) in the asymmetric hydrolysis of rac-m-chlorostyrene oxide (5a), and the highest enantioselectivity (enantiomeric ratio, E = 55.6) towards rac-phenyl glycidyl ether (7a). The catalytic efficiency (kcatS/KmS = 2.50 mM?1 s?1) of purified GmEH3 for (S)-5a was slightly higher than that (kcatR/KmR = 1.52 mM?1 s?1) for (R)-5a, whereas the kcat/Km (5.16 mM?1 s?1) for (S)-7a was much higher than that (0.09 mM?1 s?1) for (R)-7a. Using 200 mg/mL wet cells of E. coli/gmeh3 as the biocatalyst, the scale-up enantioconvergent hydrolysis of 150 mM rac-5a at 25 °C for 1.5 h afforded (R)-5b with 90.2% eep and 95.4% yieldp, while the kinetic resolution of 500 mM rac-7a for 2.5 h retained (R)-7a with over 99% ees and 43.2% yields. Furthermore, the sources of high regiocomplementarity of GmEH3 for (S)- and (R)-5a as well as high enantioselectivity towards rac-7a were analyzed via molecular docking (MD) simulation.
Asymmetric Hydrolytic and Aminolytic Kinetic Resolution of Racemic Epoxides using Recyclable Macrocyclic Chiral Cobalt(III) Salen Complexes
Tak, Rajkumar,Kumar, Manish,Menapara, Tusharkumar,Gupta, Naveen,Kureshy, Rukhsana I.,Khan, Noor-ul H.,Suresh
supporting information, p. 3990 - 4001 (2017/11/22)
New chiral macrocyclic cobalt(III) salen complexes were synthesized and used as catalyst for the asymmetric kinetic resolution (AKR) of terminal epoxides and glycidyl ethers with aromatic/aliphatic amines and water as nucleophiles. This is the first occasion where a Co(III) salen complex demonstrated its ability to catalyze AKR as well as hydrolytic kinetic resolution (HKR) reactions. Excellent enantiomeric excesses of the epoxides, the corresponding amino alcohols and diols (upto 99%) with quantitative yields were achieved by using the chiral Co(III) salen complexes in dichloromethane at room temperature. This protocol was further extended for the synthesis of two important drug molecules, i.e., (S)-propranolol and (R)-naftopidil. The catalytic system was also explored for the synthesis of chirally pure diols and chiral cyclic carbonates using carbon dioxide as a greener renewable C1 source. The catalyst was recycled for upto 5 catalytic cycles with retention of enantioselectivity. (Figure presented.).
Three different types of chirality-driven crystallization within the series of uniformly substituted phenyl glycerol ethers
Bredikhin, Alexander A.,Bredikhina, Zemfira A.,Novikova, Victorina G.,Pashagin, Alexander V.,Zakharychev, Dmitry V.,Gubaidullin, Aidar T.
, p. 1092 - 1103 (2015/02/05)
Seven chiral arylglycerol ethers 2-R-C6H4-O-CH2CH(OH)CH2OH (R 5 H, Me, Et, Allyl, n-Pr, i-Pr, tert-Bu) were synthesized in racemic and scalemic form. The IR spectra, melting points, and enthalpies of fusion for racemic and scalemic samples of every species were measured, the entropies of enantiomers mixing in the liquid state and Gibbs free energies of a racemic compound formation were derived and binary phase diagrams were reconstructed for the whole family. Solid racemic compounds stabilities were ranked for the four substances. Spontaneous resolution was established for the registered chiral drug mephenesin and its ethyl analogue. Metastable anomalous conglomerate, forming crystals having three independent R and one independent S molecules in the unit cell, is formed during solution crystallization of tert-butyl derivative; metastable phase transforms slowly into traditional racemic conglomerate. Chirality 20:1092-1103, 2008.
Asymmetric hydrolytic kinetic resolution with recyclable polymeric Co(iii)-salen complexes: A practical strategy in the preparation of (S)-metoprolol, (S)-toliprolol and (S)-alprenolol: Computational rationale for enantioselectivity
Roy, Tamal,Barik, Sunirmal,Kumar, Manish,Kureshy, Rukhsana I.,Ganguly, Bishwajit,Khan, Noor-Ul H.,Abdi, Sayed H. R.,Bajaj, Hari C.
, p. 3899 - 3908 (2015/02/19)
A series of chiral polymeric Co(iii)-salen complexes based on a number of achiral and chiral linkers were synthesized and their catalytic performances were assessed in the asymmetric hydrolytic kinetic resolution of terminal epoxides. The effects of the linker were judiciously studied and it was found that in the case of the chiral BINOL-based polymeric salen complex 1, there was an enrichment in catalyst reactivity and enantioselectivity of the unreacted epoxide, particularly in the case of short as well as long chain aliphatic epoxides. Good isolated yields of the unreacted epoxide (up to 46% compared to 50% theoretical yield) along with high enantioselectivity (up to 99%) were obtained in most cases using catalyst 1. Further studies showed that catalyst 1 could retain its catalytic activity for six cycles under the present reaction conditions without any significant loss in activity or enantioselectivity. To show the practical applicability of the above synthesized catalyst we have synthesised some potent chiral β-blockers in moderate yield and high enantioselectivity using complex 1. The DFT (M06-L/6-31+G??//ONIOM(B3LYP/6-31G?:STO-3G)) calculations revealed that the chiral BINOL linker influences the enantioselectivity achieved with Co(iii)-salen complexes. Further, the transition state calculations show that the R-BINOL linker with the (S,S)-Co(iii)-salen complex is energetically preferred over the corresponding S-BINOL linker with the (S,S)-Co(iii)-salen complex for the HKR of 1,2-epoxyhexane. The role of non-covalent C-H?π interactions and steric effects has been discussed to control the HKR reaction of 1,2-epoxyhexane.
Chiral nanoporous metal-metallosalen frameworks for hydrolytic kinetic resolution of epoxides
Zhu, Chengfeng,Yuan, Guozan,Chen, Xu,Yang, Zhiwei,Cui, Yong
supporting information; experimental part, p. 8058 - 8061 (2012/07/14)
Chiral nanoporous metal-organic frameworks are constructed by using dicarboxyl-functionalized chiral Ni(salen) and Co(salen) ligands. The Co(salen)-based framework is shown to be an efficient and recyclable heterogeneous catalyst for hydrolytic kinetic resolution (HKR) of racemic epoxides with up to 99.5% ee. The MOF structure brings Co(salen) units into a highly dense arrangement and close proximity that enhances bimetallic cooperative interactions, leading to improved catalytic activity and enantioselectivity in HKR compared with its homogeneous analogues, especially at low catalyst/substrate ratios.
An unusual (R)-selective epoxide hydrolase with high activity for facile preparation of enantiopure glycidyl ethers
Zhao, Jing,Chu, Yan-Yan,Li, Ai-Tao,Ju, Xin,Kong, Xu-Dong,Pan, Jiang,Tang, Yun,Xu, Jian-He
experimental part, p. 1510 - 1518 (2011/08/03)
A novel epoxide hydrolase (BMEH) with unusual (R)-enantioselectivity and very high activity was cloned from Bacillus megaterium ECU1001. Highest enantioselectivities (E>200) were achieved in the bioresolution of ortho-substituted phenyl glycidyl ethers and para-nitrostyrene oxide. Worthy of note is that the substrate structure remarkably affected the enantioselectivities of the enzyme, as a reversed (S)-enantiopreference was unexpectedly observed for the ortho-nitrophenyl glycidyl ether. As a proof-of-concept, five enantiopure epoxides (>99% ee) were obtained in high yields, and a gram-scale preparation of (S)-ortho-methylphenyl glycidyl ether was then successfully performed within a few hours, indicating that BMEH is an attractive biocatalyst for the efficient preparation of optically active epoxides. Copyright
Bacillus alcalophilus MTCC10234 catalyzed enantioselective kinetic resolution of aryl glycidyl ethers
Bala, Neeraj,Chimni, Swapandeep Singh,Saini, Harvinder Singh,Chadha, Bhupinder Singh
experimental part, p. 128 - 134 (2010/10/04)
The phenyl glycidyl ether derivatives have been kinetically resolved with the growing cells of Bacillus alcalophilus MTCC10234 yielding (S)-epoxides with up to >99% ee and (R)-diols with up to 89% ee. The enantiomeric ratio (E) of up to 67 has been obtained for biohydrolysis process. The effect of different substituents of phenyl glycidyl ether on the biocatalytic efficiency of B. alcalophilus MTCC10234 showed preference for methyl- and chloro-substituted aryl glycidyl ether derivatives whereas nitro-derivatives were transformed at a slower rate. 2,6-Dimethylphenyl glycidyl ether which contains a bulky aryl group having methyl group on both the ortho positions was resolved with an E=39.
