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Your search keyword '"Xiang-Ping Hu"' showing total 5 results
Start Over Author "Xiang-Ping Hu" Topic amino acids
5 results on '"Xiang-Ping Hu"'

1. Enantioselective synthesis of beta-aryl-gamma-amino acid derivatives via Cu-catalyzed asymmetric 1,4-reductions of gamma-phthalimido-substituted alpha,beta-unsaturated carboxylic acid esters

Author

Zheng-Chao Duan, Jun Deng, Sai-Bo Yu, Zhuo Zheng, Xiang-Ping Hu, Jia-Di Huang, and Dao-Yong Wang

Subjects
chemistry.chemical_classification, Molecular Structure, Chemistry, Hydrosilylation, Carboxylic acid, Imino Acids, Organic Chemistry, Enantioselective synthesis, Carboxylic Acids, Esters, Phthalimides, Stereoisomerism, Ligands, Chemical synthesis, Catalysis, Amino acid, Butyric acid, chemistry.chemical_compound, Organic chemistry, Amino Acids, Imide, Oxidation-Reduction, Copper
Abstract

A series of chiral beta-aryl-substituted gamma-amino butyric acid derivatives were synthesized in good enantioselectivities via the Cu-catalyzed asymmetric conjugate reduction of gamma-phthalimido-alpha,beta-unsaturated carboxylic acid esters using Cu(OAc)2 x H2O as a catalyst precursor, (S)-BINAP as a ligand, PMHS as a hydride source, and t-BuOH as an additive. The methodology has been applied successfully to the enantioselective synthesis of a chiral pharmaceutical, (R)-baclofen.

Published
2008

2. Enantioselective synthesis of beta2-amino acids via Rh-catalyzed asymmetric hydrogenation with BoPhoz-type ligands: important influence of an N-H proton in the ligand on the enantioselectivity

Author

Dao-Yong Wang, Zheng-Chao Duan, Jun Deng, Zhuo Zheng, Jia-Di Huang, Sai-Bo Yu, and Xiang-Ping Hu

Subjects
Spectrometry, Mass, Electrospray Ionization, Magnetic Resonance Spectroscopy, Chemistry, Ligand, Stereochemistry, Organic Chemistry, Asymmetric hydrogenation, Enantioselective synthesis, Organophosphonates, chemistry.chemical_element, Stereoisomerism, Ligands, Chemical synthesis, Catalysis, Rhodium, chemistry.chemical_compound, Michael reaction, Amino Acids, Imide
Abstract

A series of BoPhoz-type ligands were successfully applied in the rhodium-catalyzed asymmetric hydrogenation of a number of beta-substituted or unsubstituted alpha-(phthalimidomethyl)acrylates, affording good to excellent enantioselectivities. The results suggested that the presence of an N-H proton in the BoPhoz backbone could significantly improve the enantioselectivity, and ligand (Sc,Rp)-1d, bearing two CF3-groups in the 3,5-position of the phenyl ring of aminophosphino moiety, showed the highest enantioselectivity.

Published
2008

3. Rh-Catalyzed Asymmetric Hydrogenation of γ-Phthalimido-Substituted α,β-Unsaturated Carboxylic Acid Esters: An Efficient Enantioselective Synthesis of β-Aryl-γ-amino Acids

Author

Zheng-Chao Duan, Xiang-Ping Hu, Dao-Yong Wang, Xue-Feng Xu, Jun Deng, Zhuo Zheng, Jia-Di Huang, and Sai-Bo Yu

Subjects
Baclofen, Carboxylic acid, Alpha (ethology), Ligands, Biochemistry, Catalysis, chemistry.chemical_compound, Organic chemistry, Rhodium, Amino Acids, Physical and Theoretical Chemistry, Beta (finance), chemistry.chemical_classification, Molecular Structure, organic chemicals, Aryl, Asymmetric hydrogenation, Organic Chemistry, Enantioselective synthesis, Esters, Stereoisomerism, Amino acid, chemistry, Hydrogenation, Rolipram
Abstract

A series of chiral beta-aryl-gamma-amino acid ester derivatives were synthesized in high enantioselectivities (93-97% ee) via the Rh-catalyzed asymmetric hydrogenation of gamma-phthalimido-alpha,beta-unsaturated carboxylic acid esters using highly modular chiral BoPhoz-type phosphine-aminophosphine ligands. The method has been applied successfully to the synthesis of several chiral pharmaceuticals including (R)-baclofen and (R)-rolipram with high enantioselectivities.

Published
2008

4. Unsymmetrical Ferrocenylethylamine-Derived Monophosphoramidites: Highly Efficient Chiral Ligands for Rh-Catalyzed Enantioselective Hydrogenation of Enamides and α-Dehydroamino Acid Derivatives.

Author

Qing-Heng Zeng, Xiang-Ping Hu, Zheng-Chao Duan, Xin-Miao Liang, and Zhuo Zheng

Subjects
*LIGANDS (Chemistry), *HYDROGENATION, *ESTERS, *AMINO acids, *COMPLEX compounds, *ORGANIC compounds
Abstract

A new family of unsymmetrical ferrocenylethylamine-derived monophosphoramidites were synthesized and successfully applied in the Rh-catalyzed enantioselective hydrogenation of a range of enamides and α-dehydroamino acid esters, and ee values of up to 99.5% were obtained for both types of substrate. These results suggest that unsymmetrical amine-derived monophosphoramidites can also exhibit excellent enantioselectivity for a broad range of substrates, comparable to or higher than those of the most efficient symmetrical amine-derived monophosphoramidites reported thus far. [ABSTRACT FROM AUTHOR]

Published
2006
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5. Rh-Catalyzed Asymmetric Hydrogenation of -Phthalimido-Substituted ,-Unsaturated Carboxylic Acid Esters:  An Efficient Enantioselective Synthesis of -Aryl--amino Acids.

Author

Jun Deng, Zheng-Chao Duan, Jia-Di Huang, Xiang-Ping Hu, Dao-Yong Wang, Sai-Bo Yu, Xue-Feng Xu, and Zhuo Zheng

Subjects
*ORGANIC compounds, *ORGANIC acids, *CARBOXYLIC acids, *AMINO acids
Abstract

A series of chiral -aryl--amino acid ester derivatives were synthesized in high enantioselectivities (93−97% ee) via the Rh-catalyzed asymmetric hydrogenation of -phthalimido-,-unsaturated carboxylic acid esters using highly modular chiral BoPhoz-type phosphine−aminophosphine ligands. The method has been applied successfully to the synthesis of several chiral pharmaceuticals including (R)-baclofen and (R)-rolipram with high enantioselectivities. [ABSTRACT FROM AUTHOR]

Published
2007
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