- Enantioselective Catalysis for Agrochemicals: Synthetic Routes to (S)-Metolachlor, (R)-Metalaxyl and (αS,3R)-Clozylacon
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The application of enantioselective catalytic methods for the technical preparation of chiral agrochemicals is illustrated for three active ingredients of the acylanilide type. The key step for the technical synthesis of the herbicide (S)-metolachlor is the enantioselective hydrogenation of an imine intermediate using a novel iridium ferrocenyldiphosphine catalyst with an unprecedented high activity and 80 percent ee. (R)-metalaxyl and (αS,3R)-clozylacon were synthesized via the enantioselective hydrogenation of corresponding enamide precursors with Rh and Ru/binap catalysts with >95 percent and 99 percent enantiomeric purity, respectively.
- Spindler, Felix,Pugin, Benoit,Buser, Hanspeter,Jalett,Hans-Peter,Pittelkow, Ulrich,Blaser, Hans-Ulrich
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- HERBICIDAL COMPOSITIONS
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The present invention provides compositions comprising herbicidally active compounds (A) and (B), where (A) represents one or more compounds of the general formula (I) or agrochemically compatible salts thereof [component (A)], and (B) represents one or more herbicides [component (B)]. The application further relates to a method and to the use of the herbicidal composition according to the invention for controlling harmful plants or for regulating growth.
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- Method for synthesizing chiral amine compound through catalyzing asymmetric hydrogenated imine by using iridium
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The invention relates to a method for synthesizing a chiral amine compound through catalyzing high-activity high-selectivity asymmetric hydrogenated imine by using iridium. An adopted catalyst is generated in situ by an iridium-cyclooctadiene complex and a chiral phosphine-amino phosphine ligand. (S)-N-(1-methoxy-2-propyl)-2-methyl-6-ethylaniline [(S)-NAA] can be obtained by catalyzing a hydrogenation reaction of 2-methyl-6-ethyl-N-methylene aniline (EMA-imine) by using the catalyst, wherein the enantiomeric excess (ee) can reach 90%, and the molar ratio of the EMA-imine to the catalyst can beup to 1000000. Refined metolachlor with an S-configuration effective content of 94% can be obtained by carrying out an acylation reaction on the (S)-NAA with chloroacetyl chloride. Therefore, the ligand provided by the invention can be used for synthesizing the chiral herbicide metolachlor.
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Paragraph 0078-0079
(2019/03/26)
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- Synthesizing method for chloroacetamide compound
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The invention discloses a synthesizing method for a chloroacetamide compound. In a reaction kettle, a secondary amine compound is dissolved in an organic solvent, the mixture is heated for reflux, chloroacetyl chloride is added into the mixture, a reflux reaction is conducted for 0.5-20 hours, and the chloroacetamide compound is obtained. According to the synthesizing method for the chloroacetamide compound, an acid binding agent is not used, discharging of wastewater in the after-treatment process is reduced, by keeping the reflux state of the system, hydrogen chloride gas generated from thereaction is exhausted out of the system and absorbed by water outside the system, high-purity hydrochloric acid is obtained, the waste is turned into wealth, the method comes up to the production standard of safety and environment protection, and discharging of waste gas, waste water and waste residues is reduced; according to the synthesizing method for the chloroacetamide compound, few operationsteps are utilized, the reaction speed is high, the product yield is high, the purity is high, the production cost is low, and the method is safe, friendly to the environment and suitable for industrial large-scale production.
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Paragraph 0071-0073
(2019/10/01)
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- Optimized Synthetic Route for Enantioselective Preparation of (S)-Metolachlor from Commercially Available (R)-Propylene Oxide
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An enantioselective preparation of (S)-metolachlor has been accomplished. The synthetic route featured the asymmetric preparation of chiral intermediates and the final (S)-metolachlor from commercially available (R)-propylene oxide and a key Fukuyama's process. The key steps, control points, separation purifications, and the whole process are optimized, and the target compound has been successfully prepared in five steps in 51-55% overall yield with excellent enantioselectivity (99% ee) up to a 30 g scale. By judicious choice of synthetic route and selection of starting materials and intermediates, no column chromatographic methods are needed for the separation and purification of the intermediates and the final products. The same strategy was extended as a general method for a series of pesticides and herbicide analogs of Metalaxyl-M and Dimethenamid-P.
- Yang, Peng,Wang, Xiao,Peng, Lin,Chen, Feng,Tian, Fang,Tang, Chao-Zhe,Wang, Li-Xin
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p. 1682 - 1688
(2017/10/25)
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- CATALYST FOR ASYMMETRIC HYDROGENATION OF IMINE, SYNTHESIS METHOD AND APPLICATION THEREOF
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A chiral hydrogenated H8-BINOL bisphosphine compound is provided, with the structure shown as the following formula (I), wherein both R1 and R2 are halogen, H or C1-C10 aliphatic group; R3 is H or C1-C10 aliphatic group; R4 is halogen, amino, nitro, H, C1-C10 aliphatic group or C1-C10 aromatic group; and X is phenyl, substituted phenyl, cyclohexyl, substituted cyclohexyl, C6-C30 aromatic group, or C6-C30 heterocyclic aromatic group containing one or more heteroatoms selected from N, S, O. The present invention further provides a catalyst for an asymmetric catalytic hydrogenation reaction which contains the compound, wherein the catalyst can produce more than 90% of enantiomers and efficiency with the turnover number of greater than 100,000 in the asymmetric hydrogenation reaction of imines.
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Page/Page column
(2014/02/16)
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- PROCESS FOR THE HYDROGENATION OF IMINES
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A process is provided for the hydrogenation of imines with hydrogen under elevated pressure in the presence of iridium complexes as catalysts and one or more co-catalysts selected among compounds comprising a carbon-halogen bond. Further provided are novel ligands and metal complexes thereof useful for the catalytic hydrogenation of imines with hydrogen. The novel ligands are compounds of the formula (VII) or formula (VIII) in the form of racemates, mixtures of stereoisomers or optically pure stereoisomers wherein the radicals are as defined in the specification.
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Page/Page column 26
(2011/04/19)
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- PROCESS FOR THE HYDROGENATION OF IMINES
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A process is provided for the hydrogenation of imines with hydrogen under elevated pressure in the presence of iridium complexes as catalysts and one or more co-catalysts selected among compounds comprising a carbon-halogen bond. Further provided are novel ligands and metal complexes thereof useful for the catalytic hydrogenation of imines with hydrogen. The novel ligands are compounds of the formula (VII) or formula (VIII) in the form of racemates, mixtures of stereoisomers or optically pure stereoisomers, wherein the radicals are as defined in the specification.
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Page/Page column 53
(2010/09/17)
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- Chemoenzymatic synthesis of the chiral herbicide: (S)-metolachlor
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A chemoenzymatic approach for the production of (5)-metolachlor, one of the most widely used herbicides, has been developed. The starting material (S)-N-(2-ethyl-6-methylphenyl)alanine was obtained by the use of lipase-catalyzed hydrolytic kinetic resolution. Under the optimal conditions, the good activity and excellent enantioselectivity of lipase B from Candida antarctica (CAL-B, E > 100) are achieved in diethyl ether - water (15% v/v), which is about 9.7-fold more enantioselective than that in a pure buffered aqueous solution (E = 12.1). After a simple extraction procedure is used to separate the acid product from the remaining ester, the remaining ester is racemized, providing the basis for the continuous resolution process. Then (S)-metolachlor is synthesized by a simple chemical method using the enantiomerically pure (S)-acid.
- Zheng, Liangyu,Zhang, Suoqin,Wang, Fang,Gao, Gui,Cao, Shugui
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p. 1058 - 1063
(2007/10/03)
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- PROCESS FOR PREPARING AMINES AND A CARBOXAMIDE THEREOF
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Chiral, secondary amines of the formula (I) or (II), where R01, R02 and R03 are each, independently of one another, C1-C4-alkyl, R04 is C1-C4-alkyl, C1-C4-alkoxymethyl or C1-C4-alkoxyethyl, and * indicates predominantly one configurational isomer, can be obtained by hydrogenation of corresponding ketimines in the presence of iridium complexes with chiral ferrocene tetraphosphines in which a secondary phosphine group and 1-secondary phosphinalk-1-yl are bound to each cyclopentadienyl ring in ortho positions.
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Page/Page column 23
(2010/02/15)
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- (S)-[14C]DUAL: Stereoselective synthesis and use of chiral phases
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(S)-Metolachlor (DUAL MAGNUM), a potent herbicide of the acylanilide type, has been prepared radiolabelled with carbon-14 in the phenyl ring.
- Respondek, M.,Spindler, F.
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p. 1066 - 1067
(2007/10/03)
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- ENANTIOSELECTIVE SYNTHESIS OF OPTICALLY ACTIVE METOLACHLOR VIA ASYMMETRIC REDUCTION
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Optically active metolachlor was prepared by chloroacetylation of the corresponding amine obtained by asymmetric reduction of the requisite imine with the chiral hydrides, such as Itsuno's reagent (4), Corey's reagent (5) and K glucoride (6).
- Cho, Byung Tae,Chun, Yu Sung
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p. 337 - 340
(2007/10/02)
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