53940-88-8Relevant articles and documents
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 0362-0368, (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.
Enantiocatalytic activity of substituted 5-benzyl-2-(pyridine-2-yl) imidazolidine-4-one ligands
Drabina, Pavel,Karel, Sergej,Panov, Illia,Sedlak, Milos
, p. 334 - 339 (2013/04/23)
Currently, asymmetric synthesis represents one of the main streams of organic synthesis. Although an extensive research has been carried out in this area, the synthesis of chiral compounds with the required enantiomeric purity is still a challenging issue. Herein, we focus on the preparation of new enantioselective catalysts based on pyridine-imidazolidinones. The substituted 5-benzyl-2-(pyridine-2-yl)imidazolidine-4-ones 5-8 were prepared by condensation of chiral amino acid amides (α-methylDOPA and α- methylphenylalanine) with 2-acetylpyridine and pyridine-2-carbaldehyde. The individual isomers of the described ligands 5-8 were separated chromatographically. The copper(II) complexes of these chiral ligands were studied as enantioselective catalysts for the asymmetric Henry reaction of substituted aldehydes with nitromethane or nitroethane. The ligands containing a methyl group at the 2-position of the imidazolidinone ring 6a and 8a exhibit a high degree of enantioselectivity (up to 91% ee). The nitroaldols derived from nitroethane (2-nitropropan-1-ols) were obtained with a comparable enantiomeric purity to derivatives of 2-nitroethanol. This group of ligands represents a new and promising class of enantioselective catalysts, which deserve further attention.
Non-enzymatic diastereoselective asymmetric desymmetrization of 2-benzylserinols giving optically active 4-benzyl-4-hydroxymethyl-2- oxazolidinones: Asymmetric syntheses of α-(hydroxymethyl)phenylalanine, N-Boc-α-methylphenylalanine, cericlamine and BIRT-377
Sugiyama, Shigeo,Arai, Satoshi,Ishii, Keitaro
, p. 8033 - 8045 (2012/10/07)
A reaction of (S)-2-benzyl-2-(α-methylbenzyl)amino-1,3-propanediol (S)-4a and 2-chloroethyl chloroformate, and the subsequent addition of DBU gave (4R,αS)-4-benzyl-4-hydroxymethyl-3-(α-methylbenzyl)-2-oxazolidinone (4R)-5a (92% de) via a diastereoselective asymmetric desymmetrization process. Debenzylation of (4R)-5a using trifluoromethanesulfonic acid and anisole in MeNO2 gave (R)-4-benzyl-4-hydroxymethyl-2-oxazolidinone (R)-15a, which was converted into (R)-(α-hydroxymethyl)phenylalanine (7) in two steps. N-Boc-α-methylphenylalanine (8), cericlami0ne (9) and BIRT-377 (10) were also synthesized using these asymmetric desymmetrization and debenzylation.
