52616-59-8Relevant academic research and scientific papers
Operationally Convenient and Scalable Asymmetric Synthesis of (2S)- and (2R)-α-(Methyl)cysteine Derivatives through Alkylation of Chiral Alanine Schiff Base NiII Complexes
Yamamoto, Junya,Kawashima, Aki,Kawamura, Akie,Abe, Hidenori,Moriwaki, Hiroki,Shibata, Norio,Soloshonok, Vadim A.
, p. 1931 - 1939 (2017/04/24)
This research demonstrates that the methylation of N-benzyl cysteine Schiff base derived NiII complexes leads to the formation of the corresponding dehydroalanine-containing products and cannot be used for preparation of the target α-(methyl)cysteine. In sharp contrast, the alternative strategy that involves thiomethylation of NiII complexes of alanine Schiff bases is a viable and practically attractive approach to afford the desired α-(methyl)cysteine containing derivatives. This work also reveals a significant, and rather unexpected, difference in the stereochemical performance of proline and 3,5-dihydro-4H-dinaphth[2,1-c:1′,2′-e]azepine derived chiral ligands, the former of which shows superior performance in terms of chemical yields and diastereoselectivity of the α-(methyl)cysteine products formed.
METHOD FOR SYNTHESIZING OPTICALLY ACTIVE a-AMINO ACID USING CHIRAL METAL COMPLEX COMPRISING AXIALLY CHIRAL N-(2-ACYLARYL)-2-[5,7-DIHYDRO-6H-DIBENZO[c,e]AZEPIN-6-YL] ACETAMIDE COMPOUND AND AMINO ACID
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Paragraph 0456-0463, (2016/05/10)
Objects of the present invention are to provide an industrially applicable method for producing an optically active α-amino acid in high yield and in a highly enantioselective manner, to provide a simple production method of an optically active α,α-disubstituted α-amino acid, and to provide an intermediate useful for the above production methods of an optically active α-amino acid and an optically active α,α-disubstituted α-amino acid. The present invention provides a production method of an optically active α-amino acid or a salt thereof, the production method comprising introducing a substituent into the α carbon in the α-amino acid moiety of a metal complex represented by the following Formula (1): by an alkylation reaction, an aldol reaction, the Michael reaction, or the Mannich reaction, and releasing an optically pure α-amino acid enantiomer or a salt thereof by acid decomposition of the metal complex.
METHOD FOR SYNTHESIZING OPTICALLY ACTIVE α-AMINO ACID USING CHIRAL METAL COMPLEX COMPRISING AXIALLY CHIRAL N-(2-ACYLARYL)-2-[5,7-DIHYDRO-6H-DIBENZO[c,e]AZEPIN-6-YL]ACETAMIDE COMPOUND AND AMINO ACID
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Paragraph 0782; 0784-0786; 0797, (2016/11/17)
Objects of the present invention are to provide an industrially applicable method for producing an optically active ±-amino acid in high yield and in a highly enantioselective manner, to provide a simple production method of an optically active ±,±-disubstituted ±-amino acid, and to provide an intermediate useful for the above production methods of an optically active ±-amino acid and an optically active ±,±-disubstituted ±-amino acid. The present invention provides a production method of an optically active ±-amino acid or a salt thereof, the production method comprising introducing a substituent into the ± carbon in the ±-amino acid moiety of a metal complex represented by the following Formula (1): by an alkylation reaction, an aldol reaction, the Michael reaction, or the Mannich reaction, and releasing an optically pure ±-amino acid enantiomer or a salt thereof by acid decomposition of the metal complex.
NOVEL CRYSTAL MODIFICATIONS
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Page/Page column 62-63, (2008/06/13)
Novel crystal modifications of (5S)-5-[4-(5-chloro-pyridin-2-yloxy)-piperidine-1-sulfonylmethyl]-5-methyl-imidazolidine-2,4-dione are disclosed together with processes for preparing such modifications, pharmaceutical compositions comprising such a modification, and the use of such a modification in therapy.
PROCESS FOR PRODUCING L-a-METHYLCYSTEINE DERIVATIVE
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, (2008/06/13)
A process for easily producing an L-α-methylcysteine derivative or its salt, which is useful as a drug intermediate, from a cheap easily procurable raw material through an enzymatic D-stereoselective hydrolysis of racemic 5-halomethyl-5-methyl-hydantoin. L-α-methylcysteine derivative or its salt is produced by converting racemic 5-halomethyl-5-methylhydantoin to L-5-halomethyl-5-methylhydantoin through an enzymatic D-stereoselective hydrolysis, reacting the L-5-halomethyl-5-methylhydantoin with a sulfurizing agent into L-5-methyl-5-thiomethylhydantoin and hydrolyzing the L-5-methyl-5-thiomethylhydantoin.
Total synthesis of thiangazole
Akaji, Kenichi,Kiso, Yoshiaki
, p. 10685 - 10694 (2007/10/03)
A method for total synthesis of thiangazole (1), a tris-thiazoline- oxazole metabolite, is described. The key intermediate 9, a linear tetrapeptide amide composed of three S-benzyl-2-methylcysteine residues and a O-benzyl-threonine amide, was synthesized in 4 steps using 2-chloro-1,3- dimethyl-imidazolidium hexafluorophosphate(CIP)mediated activation. The successive thiazoline/oxazole rings were constructed by TiCl4mediated cycledehydration followed by acid-catalyzed Robinson-Gabriel reaction without difficulty.
