- Novel method for asymmetric synthesis of (1S,2S)-2-fluorocyclopropanecarboxylic acid under catalysis of chiral rhodium catalyst
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The invention provides a novel method for asymmetric synthesis of (1S, 2S)-2-fluorocyclopropanecarboxylic acid under catalysis of a chiral rhodium catalyst. The chiral rhodium catalyst not only can catalyze 1-fluoro-1-benzenesulfonyl ethylene and ethyl di
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Paragraph 0124-0125; 0128-0129
(2019/12/02)
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- PROCESS FOR PRODUCING 1,2-CIS-2-FLUOROCYCLOPROPANE-1-CARBOXYLIC ESTER COMPOUND
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Provided is an industrially applicable process for producing 1,2-cis-2-fluorocyclopropane-1-carboxylic ester. A process for producing a compound represented by formula (3): [wherein R 1 represents, for example, a C1-C8 alkyl group], which process includes reacting a compound represented by formula (1) : [wherein X 1 represents a hydrogen atom, a chlorine atom, a bromine atom, or an iodine atom; X 2 represents a hydrogen atom, a chlorine atom, a bromine atom, or an iodine atom; X 1 and X 2 are not simultaneously hydrogen atoms; and R 1 has the same meaning as defined in formula (3)] with a reducing agent represented by formula (2): €?€?€?€?€?€?€?€?M 1 BH m R 2 n (2-1) or M 2 (BH m R 2 n ) 2 €?€?€?€?€?(2-2) [wherein M 1 represents an alkali metal atom; M 2 represents an alkaline earth metal atom or a zinc atom; R 2 represents, for example, a hydrogen atom; m represents an integer from 1 to 4; n represents an integer from 0 to 3; and the sum of m and n is 4] in the presence of an aprotic polar solvent, and a Lewis acid such as a halide of an atom selected from among, for example, boron, magnesium, and aluminum.
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Page/Page column 10-11
(2008/06/13)
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- PROCESS FOR PREPARING HALOGENATED CYCLOPROPANE DERIVATIVES
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A process for preparing compounds represented by the following general formula (I) wherein X represents chlorine atom or other and R represents alkoxy group, amino group or other, which comprises the step of allowing a compound represented by the formula: CH2═CXF react with a compound represented by the formula: N2CHCOR in the presence of a catalyst containing a metal atom such as a transition metal of group 8 together with chiral carboxylic-type or amide-type ligands to preferentially obtain a stereoisomer of the compound of the general formula (I) wherein the stereochemical configuration at the 1-position is S-configuration
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- Process for producing 2-fluorine-1-cyclopropane carboxylic acid derivatives by reductive dehalogenation
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PCT No. PCT/EP97/02210 Sec. 371 Date Nov. 16, 1998 Sec. 102(e) Date Nov. 16, 1998 PCT Filed Apr. 30, 1997 PCT Pub. No. WO97/44309 PCT Pub. Date Nov. 27, 1997Cyclopropanecarboxylic acid derivatives are prepared by reacting halogenocyclopropanecarboxylic acid derivatives with metals in the presence of bases and with or without addition of hydrogen in an advantageous manner if the base is added during the reaction. By means of the process according to the invention, good yields and selectivities and a high proportion of cis isomers in the reaction product may be achieved.
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- Resolution of cis-2-fluorocyclopropanecarboxylic acid by a microbial enantioselective hydrolysis
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The important key intermediate of quinolone analogue synthesis, (1S,2S)- 2-fluorocyclopropanecarboxylic acid, was prepared enantioselectively by a microbial resolution. One of the strains with the highest enzymatic specificity was selected from soil and when lyophilized cells were treated with corresponding ester, the remaining (1S,2S)-ester was obtained with high enantiomeric purity (98% e.e.).
- Imura, Akihiro,Itoh, Motohiro,Miyadera, Akihiko
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p. 3047 - 3052
(2007/10/03)
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- Selective dehalogenation process
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A compound represented by the following formula (1) or (3): STR1 is subjected to a catalytic hydrogenolysis reaction in the presence of a base and thus a compound represented by the following formula (2): STR2 wherein R represents a hydrogen atom or an al
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