57646-33-0Relevant articles and documents
Enantiomerization and enantioselective bioaccumulation of metalaxyl in tenebrio molitor larvae
Gao, Yongxin,Wang, Huili,Qin, Fang,Xu, Peng,Lv, Xiaotian,Li, Jianzhong,Guo, Baoyuan
, p. 88 - 94 (2014)
The enantiomerization and enantioselective bioaccumulation of metalaxyl by a single dose of exposure to Tenebrio molitor larvae under laboratory condition were studied by high-performance liquid chromatography tandem mass spectroscopy (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris-tris-(3, 5-dichlorophenyl-carbamate)] column. Exposure of enantiopure R-metalaxyl and S-metalaxyl in Tenebrio molitor larvae exhibited significant enantiomerization, with formation of the R enantiomers from the S enantiomers, and vice versa, which might be attributed to the chiral pesticide catalyzed by a certain enzyme in Tenebrio molitor larvae. Enantiomerization was not observed in wheat bran during the period of 21 d. In addition, bioaccumulation of rac-metalaxyl in Tenebrio molitor larvae was enantioselective with a preferential accumulation of S-metalaxyl. These results showed that enantioselectivity was caused not only by actual degradation and metabolism but also by enantiomerization, which was an important process in the environmental fate and behavior of metalaxyl enantiomers.
Chiral ferrocene-imidazole diphosphine ligand as well as synthesis method and application thereof
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Paragraph 0047-0051; 0060-0063, (2021/05/22)
The invention relates to a chiral ferrocene-imidazole diphosphine ligand as well as a preparation method and application thereof. The synthesis method comprises the following steps: dissolving ferrocenyl chiral alcohol and N, N '-carbonyldiimidazole, whic
Iridium/chiral diphosphine system catalyzed imine asymmetric hydrogenation method
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Paragraph 0060-0069; 0084-0089, (2019/12/25)
The invention discloses a method for catalyzing asymmetric hydrogenation of imines by an iridium/chiral diphosphine system, which comprises the following steps: reacting a chiral diphosphine ligand with a metal iridium precursor to prepare a complex in situ as a catalyst, and carrying out asymmetric hydrogenation on imines to prepare a chiral amine. The ligand is simple to prepare; catalyst dosage, simple operation, continuous operation can be realized, the preparation method is simple in process and suitable for large-scale preparation of chiral amine, the enantiomeric excess value of the product reaches 80% or above, and the preparation method has is excellent in effect when the S/C (2-ethyl-6-methylaniline/catalyst) rate is 500,000 during synthesis of the s-metolachlor intermediate, theyield reaches 95%, the enantioselectivity reaches 91%, and good industrial practicability is achieved.
Ir-catalyzed Asymmetric Hydrogenation of α-Imino Esters with Chiral Ferrocenylphosphine-Phosphoramidite Ligands
Hu, Xin-Hu,Hu, Xiang-Ping
, p. 5063 - 5068 (2019/11/11)
An Ir-catalyzed asymmetric hydrogenation of α-imino esters with unsymmetrical hybrid chiral ferrocenylphosphine-phosphoramidite ligands for the synthesis of optically active α-aryl glycines has been described. The result indicated that the presence of the iodo-substitutent at the 3/3’-position of the binaphthyl unit of ligand could significantly improve the catalytic performance. This method features high asymmetric induction and reasonable functional group tolerance, thus providing a concise and efficient approach toward chiral α-aryl glycine derivatives with up to 96% ee.
Method for preparing chiral amine by asymmetric hydrogenation of imine
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Paragraph 0042; 0043; 0061; 0062, (2019/03/26)
The invention discloses a method for preparing chiral amine by asymmetric hydrogenation of imine. Chiral ferrocene phosphine-diformamidine imine reacts with a metal iridium precursor in situ to prepare a complex which is used as a catalyst, and asymmetric
Synthesis method of optically active metalaxyl
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Paragraph 0031; 0040; 0041; 0050; 0051; 0060; 0061; 0070, (2019/01/21)
The invention discloses a synthesis method of optically active metalaxyl. The optically active metalaxyl is synthesized by performing methoxylation and acylating chlorination on chloroacetic acid to obtain methoxyacetyl chloride and then reacting Methoxyacetyl chloride with D-N-(2,6-dimethylphenyl) alanine methyl ester; a one-pot method operation is adopted for the synthesis; the two-step reactionof methoxylation and acylating chlorination is directly used for a next-step reaction without post-treatment. According to the process of the optically active metalaxyl, by adopting the one-pot method operation, the operation steps are simplified, the production of three wastes is decreased, the synthesis cost is reduced, the obtained product is stable in quality and relatively high in output andyield, and the synthesis method is suitable for large-scale production.
Chiral phosphine-phosphoramidite ligands for highly enantioselective hydrogenation of N-arylimines
Li, Qing,Hou, Chuan-Jin,Liu, Xiao-Ning,Huang, De-Zhi,Liu, Yan-Jun,Yang, Rui-Feng,Hu, Xiang-Ping
, p. 13702 - 13708 (2015/02/19)
The asymmetric hydrogenation of N-arylimines with the chiral phosphine-phosphoramidite ligand, (Sc,Sa)-PEAPhos 2b, has been developed. The results revealed that the presence of the substituents on the 3,3′-positions of the binaphthyl backbone significantly improved the enantioselectivity. The utility of this methodology was demonstrated in the synthesis of the chiral fungicide (R)-metalaxyl. This journal is
N-(Chloroacetyl)- and N-(dichloroacetyl)-N-(xylyl)alanine esters: Assignment of the absolute configurations and enantiodifferentiation by the dirhodium method
Diaz Gomez, Edison,Jios, Jorge,Della Vedova, Carlos O.,March, Hugo D.,Di Loreto, Hector E.,Toth, Gabor,Simon, Andras,Albert, Dieter,Moeller, Stefan,Wartchow, Rudolf,Duddeck, Helmut
, p. 2285 - 2293 (2007/10/03)
Four chlorinated N-acylalanine methylesters (metalaxyl derivatives) containing either stereogenic centres alone as in 1 and 3 or stereogenic centres plus chiral axes as in 2 and 4 were investigated. The latter have been examined in terms of the absolute c
Enzyme-catalyzed preparation of methyl (R)-N-(2,6-dimethylphenyl)alaninate: A key intermediate for (R)-metalaxyl
Park, Oh-Jin,Lee, Sang-Hyun,Park, Tae-Yoon,Lee, Sang-Who,Cho, Koon-Ho
, p. 1221 - 1225 (2007/10/03)
A biocatalytic approach for the production of (R)-metalaxyl, mefenoxam, has been developed. A practical synthesis of methyl (R)-N-(2,6-dimethylphenyl) alaninate, a key intermediate for (R)-metalaxyl, has been developed by the use of lipase-catalyzed hydrolytic kinetic resolution and chemical racemization of the remaining ester. At high concentrations in aqueous media (300 g/L) lipases were stable and gave moderate to good conversions and excellent enantioselectivities (>98% ee). A simple extraction procedure was used to separate the acid product from the remaining ester and the acid was esterified with methanol to give methyl (R)-N-(2,6-dimethylphenyl)alaninate without any reduction in enantiomeric excess (>98% ee). Subsequent chemical coupling with methoxyacetyl chloride provided enantiomerically pure (R)-metalaxyl (>98% ee) without racemization.
Iridium-imine and -amine complexes relevant to the (S)-metolachlor process: Structures, exchange kinetics, and C-H activation by IrI causing racemization
Dorta, Romano,Broggini, Diego,Kissner, Reinhard,Togni, Antonio
, p. 4546 - 4555 (2007/10/03)
Iridium complexes of DMA-imine [2,6-dimethylphenyl-1′-methyl- 2′-methoxyethylimine, 1a) and (R)-DMA-amine [(1′R)-2,6- dimethylphenyl-1′-methyl-2′-methoxyethylamine, 2a] that are relevant to the catalytic imine hydrogenation step of the Syngenta (S)-Metola
