Enantiocatalytic activity of substituted 5-benzyl-2-(pyridine-2-yl)imidazolidine-4-one ligands
摘要:
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 (alpha-methylDOPA and alpha-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 enantioselectiyity (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. (C) 2013 Elsevier Ltd. All rights reserved.
Enantiocatalytic activity of substituted 5-benzyl-2-(pyridine-2-yl)imidazolidine-4-one ligands
摘要:
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 (alpha-methylDOPA and alpha-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 enantioselectiyity (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. (C) 2013 Elsevier Ltd. All rights reserved.
2,4,6-Substituted Pyridyl Derivative Compounds Useful as Beta-Secretase Inhibitors for the Treatment of Alzheimer's Disease
申请人:Barrow C. James
公开号:US20080015233A1
公开(公告)日:2008-01-17
The present invention is directed to 2,4,6-substituted pyridyl derivative compounds which are inhibitors of the beta-secretase enzyme and that are useful in the treatment of diseases in which the beta-secretase enzyme is involved, such as Alzheimer's disease. The invention is also directed to pharmaceutical compositions comprising these compounds and the use of these compounds and compositions in the treatment of such diseases in which the beta-secretase enzyme is involved.
Highly Sterically Hindered Peptide Bond Formation between α,α-Disubstituted α-Amino Acids and <i>N</i>-Alkyl Cysteines Using α,α-Disubstituted α-Amidonitrile
作者:Xiaoling Wang、Jing Li、Yujiro Hayashi
DOI:10.1021/jacs.2c02993
日期:2022.6.15
sterically hindered peptides, research on peptides bearing an amide bond between an α,α-disubstituted α-aminoacid and an N-alkyl α-aminoacid remains underexplored because of the lack of an efficient synthetic approach. Herein, we describe a high-yielding synthetic method to access such extremely sterically hindered peptide bonds between amino acids. The reaction takes place between a peptide with an α,α-disubstituted
Design, synthesis and biological evaluation of peptide derivatives of l-dopa as anti-parkinsonian agents
作者:Tao Zhou、Robert C. Hider、Peter Jenner、Bruce Campbell、Christopher J. Hobbs、Sarah Rose、Mark Jairaj、Kayhan A. Tayarani-Binazir、Alexander Syme
DOI:10.1016/j.bmcl.2013.08.007
日期:2013.10
A series of dipeptide derivatives of L-dopa were synthesized and investigated for their pharmacological activity using the unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rat as an experimental model of Parkinson's disease. Among them, (S)-isopropyl 2-(2-amino-2-methylpropanamido)-3-(3,4-dihydroxyphenyl) propanoate (4g) was found to be the most active compound, with 106% AUC activity and 149% peak activity of L-dopa after oral administration. (C) 2013 Elsevier Ltd. All rights reserved.
2, 4, 6-SUBSTITUTED PYRIDYL DERIVATIVE COMPOUNDS USEFUL AS BETA-SECRETASE INHIBITORS FOR THE TREATMENT OF ALZHEIMER'S DISEASE