51077-16-8Relevant articles and documents
Asymmetric Michael reaction promoted by chiral thiazolidine-thiourea catalyst
da Silva, Tiago Lima,Rambo, Raoni Scheibler,Jacoby, Caroline Gross,Schneider, Paulo Henrique
supporting information, (2019/12/27)
In this work, we report the synthesis and characterization of three new thiazolidine- and thiourea-based chiral organocatalysts. These compounds were successfully applied in asymmetric Michael addition reactions between different ketones and nitrostyrenes leading to products in up to 85% yield, >96:4 r.d. and 97% e.e. Computational studies were used to better visualize the proposed transition state and explain the observed stereoselectivities. One of the new catalysts was also successfully applied in an aldol addition between cyclohexanone an p-nitrobenzaldehyde leading to product in 80% yield, >96:4 d.r. and 80% e.e.
Synthesis of new thiazolidine based organocatalysts and their application to asymmetric aldol reaction
Cicek, Mahmut,Aydogan, Feray,Yolacan, Cigdem
, p. 778 - 786 (2017/12/28)
Background: Proline and its derivatives are versatile organocatalysts for many reactions. Especially prolinamide derivatives have been prepared and investigated in aldol reaction successfully. Generally, derivatizations have been made on side chain of proline to develop new effective catalysts. But, there are only few examples of different cyclic systems other than pyrrolidine ring used as chiral organocatalysts. Method: The methodology for this study was the synthesis of new thiazolidine-4-carboxylic acid based organocatalysts and investigation of their catalytic activities in asymmetric direct aldol reactions. Results: New thiazolidine based organocatalysts 6a-g [substituted (4R)-N-[(2S)-1-amino-1-oxo-3-phenyl-2-propyl]-4-thiazolidinecarboxamides] were synthesized and characterized. Their catalytic activity studies in asymmetric direct aldol reactions of aliphatic ketones with arylaldehydes were performed. Among the catalysts investigated in this study, especially methyl (2S)-3-phenyl-2-[(2S)-3-phenyl-2-[(4R)-thiazolidine-4-carboxamido]propanamido]propanoate (6a) and (4R)-N-[(2S)-1-(benz-hydrylamino)-1-oxo-3-phenyl-2-propyl]-4-thiazolidinecarboxamide (6b) gave the best diastereoselectivities (up to 91%), enantioselectivities (up to 88%) and yields (up to 94%) when different aliphatic ketones and aromatic aldehydes with electron withdrawing groups were used. Conclusion: Some new organocatalysts derived from thiazolidine-4-carboxylic acid were designed, synthesized, and successfully used in the direct asymmetric aldol reaction of aliphatic ketones and aromatic aldehydes under solvent free conditions. The results showed that these new products were promising organocatalysts for aldol reaction.
BENZIDINE DERIVATIVE, METHOD FOR PREPARING SAME, AND PHARMACEUTICAL COMPOSITION CONTAINING BENZIDINE DERIVATIVE FOR TREATING LIVER DISEASE CAUSED BY HEPATITIS C VIRUS
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Paragraph 0177; 0178; 0179; 0180, (2016/02/24)
The disclosed compounds have antiviral activity against C-type virus, an optical isomer thereof, a pharmaceutically acceptable salt thereof, a method for preparing the same, and a pharmaceutical composition containing the same as an active ingredient for preventing or treating liver disease caused by hepatitis C virus. The benzidine derivative according to the present invention has excellent antiviral activity against hepatitis C virus and exhibits excellent medicinal activity in the living body, and thus the pharmaceutical composition containing the same as an active ingredient can be useful as a pharmaceutical composition for preventing or treating liver disease, such as acute hepatitis C, chronic hepatitis C, cirrhosis, or hepatocellular carcinoma, caused by C-type virus.
