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Gong Chen - One of the best experts on this subject based on the ideXlab platform.
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construction of cyclophane braced peptide macrocycles via palladium catalyzed Picolinamide directed intramolecular c sp2 h arylation
Organic Letters, 2020Co-Authors: Bo Li, Gang He, Liping Qi, Peng Yang, Gong ChenAbstract:A versatile method for the construction of C(sp2)-linked cyclophane peptide macrocycles via Pd-catalyzed Picolinamide-directed intramolecular arylation of aryl and alkenyl C-H bonds of amino acid side chains with aryl iodides is developed. This method provides simple and efficient access to a variety of cyclophane-braced structures from readily accessible linear peptide precursors.
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palladium catalyzed Picolinamide directed iodination of remote ortho c h bonds of arenes synthesis of tetrahydroquinolines
Beilstein Journal of Organic Chemistry, 2016Co-Authors: William A Nack, Xinmou Wang, Gang He, Bo Wang, Gong ChenAbstract:A new palladium-catalyzed Picolinamide (PA)-directed ortho-iodination reaction of e-C(sp2)−H bonds of γ-arylpropylamine substrates is reported. This reaction proceeds selectively with a variety of γ-arylpropylamines bearing strongly electron-donating or withdrawing substituents, complementing our previously reported PA-directed electrophilic aromatic substitution approach to this transformation. As demonstrated herein, a three step sequence of Pd-catalyzed γ-C(sp3)−H arylation, Pd-catalyzed e-C(sp2)−H iodination, and Cu-catalyzed C−N cyclization enables a streamlined synthesis of tetrahydroquinolines bearing diverse substitution patterns.
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Palladium-catalyzed Picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines
Beilstein Journal of Organic Chemistry, 2016Co-Authors: William A Nack, Xinmou Wang, Gang He, Bo Wang, Gong ChenAbstract:A new palladium-catalyzed Picolinamide (PA)-directed ortho-iodination reaction of e-C(sp2)−H bonds of γ-arylpropylamine substrates is reported. This reaction proceeds selectively with a variety of γ-arylpropylamines bearing strongly electron-donating or withdrawing substituents, complementing our previously reported PA-directed electrophilic aromatic substitution approach to this transformation. As demonstrated herein, a three step sequence of Pd-catalyzed γ-C(sp3)−H arylation, Pd-catalyzed e-C(sp2)−H iodination, and Cu-catalyzed C−N cyclization enables a streamlined synthesis of tetrahydroquinolines bearing diverse substitution patterns.
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palladium catalyzed Picolinamide directed halogenation of ortho c h bonds of benzylamine substrates
ChemInform, 2014Co-Authors: Chengxi Lu, Gang He, William A Nack, Shuyu Zhang, Gong ChenAbstract:The presented method features the use of an unique combination of alkali chlorate, bromate, or iodate together with potassium persulfate enabling the installation of the corresponding halogen onto the ortho position of N-benzyl Picolinamides.
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Palladium‐Catalyzed Picolinamide‐Directed Halogenation of ortho C—H Bonds of Benzylamine Substrates.
ChemInform, 2014Co-Authors: Chengxi Lu, Gang He, William A Nack, Shuyu Zhang, Gong ChenAbstract:The presented method features the use of an unique combination of alkali chlorate, bromate, or iodate together with potassium persulfate enabling the installation of the corresponding halogen onto the ortho position of N-benzyl Picolinamides.
Gang He - One of the best experts on this subject based on the ideXlab platform.
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construction of cyclophane braced peptide macrocycles via palladium catalyzed Picolinamide directed intramolecular c sp2 h arylation
Organic Letters, 2020Co-Authors: Bo Li, Gang He, Liping Qi, Peng Yang, Gong ChenAbstract:A versatile method for the construction of C(sp2)-linked cyclophane peptide macrocycles via Pd-catalyzed Picolinamide-directed intramolecular arylation of aryl and alkenyl C-H bonds of amino acid side chains with aryl iodides is developed. This method provides simple and efficient access to a variety of cyclophane-braced structures from readily accessible linear peptide precursors.
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palladium catalyzed Picolinamide directed iodination of remote ortho c h bonds of arenes synthesis of tetrahydroquinolines
Beilstein Journal of Organic Chemistry, 2016Co-Authors: William A Nack, Xinmou Wang, Gang He, Bo Wang, Gong ChenAbstract:A new palladium-catalyzed Picolinamide (PA)-directed ortho-iodination reaction of e-C(sp2)−H bonds of γ-arylpropylamine substrates is reported. This reaction proceeds selectively with a variety of γ-arylpropylamines bearing strongly electron-donating or withdrawing substituents, complementing our previously reported PA-directed electrophilic aromatic substitution approach to this transformation. As demonstrated herein, a three step sequence of Pd-catalyzed γ-C(sp3)−H arylation, Pd-catalyzed e-C(sp2)−H iodination, and Cu-catalyzed C−N cyclization enables a streamlined synthesis of tetrahydroquinolines bearing diverse substitution patterns.
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Palladium-catalyzed Picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines
Beilstein Journal of Organic Chemistry, 2016Co-Authors: William A Nack, Xinmou Wang, Gang He, Bo Wang, Gong ChenAbstract:A new palladium-catalyzed Picolinamide (PA)-directed ortho-iodination reaction of e-C(sp2)−H bonds of γ-arylpropylamine substrates is reported. This reaction proceeds selectively with a variety of γ-arylpropylamines bearing strongly electron-donating or withdrawing substituents, complementing our previously reported PA-directed electrophilic aromatic substitution approach to this transformation. As demonstrated herein, a three step sequence of Pd-catalyzed γ-C(sp3)−H arylation, Pd-catalyzed e-C(sp2)−H iodination, and Cu-catalyzed C−N cyclization enables a streamlined synthesis of tetrahydroquinolines bearing diverse substitution patterns.
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palladium catalyzed Picolinamide directed halogenation of ortho c h bonds of benzylamine substrates
ChemInform, 2014Co-Authors: Chengxi Lu, Gang He, William A Nack, Shuyu Zhang, Gong ChenAbstract:The presented method features the use of an unique combination of alkali chlorate, bromate, or iodate together with potassium persulfate enabling the installation of the corresponding halogen onto the ortho position of N-benzyl Picolinamides.
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Palladium‐Catalyzed Picolinamide‐Directed Halogenation of ortho C—H Bonds of Benzylamine Substrates.
ChemInform, 2014Co-Authors: Chengxi Lu, Gang He, William A Nack, Shuyu Zhang, Gong ChenAbstract:The presented method features the use of an unique combination of alkali chlorate, bromate, or iodate together with potassium persulfate enabling the installation of the corresponding halogen onto the ortho position of N-benzyl Picolinamides.
William A Nack - One of the best experts on this subject based on the ideXlab platform.
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Palladium-catalyzed Picolinamide-directed iodination of remote ortho-C−H bonds of arenes: Synthesis of tetrahydroquinolines
Beilstein Journal of Organic Chemistry, 2016Co-Authors: William A Nack, Xinmou Wang, Gang He, Bo Wang, Gong ChenAbstract:A new palladium-catalyzed Picolinamide (PA)-directed ortho-iodination reaction of e-C(sp2)−H bonds of γ-arylpropylamine substrates is reported. This reaction proceeds selectively with a variety of γ-arylpropylamines bearing strongly electron-donating or withdrawing substituents, complementing our previously reported PA-directed electrophilic aromatic substitution approach to this transformation. As demonstrated herein, a three step sequence of Pd-catalyzed γ-C(sp3)−H arylation, Pd-catalyzed e-C(sp2)−H iodination, and Cu-catalyzed C−N cyclization enables a streamlined synthesis of tetrahydroquinolines bearing diverse substitution patterns.
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palladium catalyzed Picolinamide directed iodination of remote ortho c h bonds of arenes synthesis of tetrahydroquinolines
Beilstein Journal of Organic Chemistry, 2016Co-Authors: William A Nack, Xinmou Wang, Gang He, Bo Wang, Gong ChenAbstract:A new palladium-catalyzed Picolinamide (PA)-directed ortho-iodination reaction of e-C(sp2)−H bonds of γ-arylpropylamine substrates is reported. This reaction proceeds selectively with a variety of γ-arylpropylamines bearing strongly electron-donating or withdrawing substituents, complementing our previously reported PA-directed electrophilic aromatic substitution approach to this transformation. As demonstrated herein, a three step sequence of Pd-catalyzed γ-C(sp3)−H arylation, Pd-catalyzed e-C(sp2)−H iodination, and Cu-catalyzed C−N cyclization enables a streamlined synthesis of tetrahydroquinolines bearing diverse substitution patterns.
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palladium catalyzed Picolinamide directed halogenation of ortho c h bonds of benzylamine substrates
ChemInform, 2014Co-Authors: Chengxi Lu, Gang He, William A Nack, Shuyu Zhang, Gong ChenAbstract:The presented method features the use of an unique combination of alkali chlorate, bromate, or iodate together with potassium persulfate enabling the installation of the corresponding halogen onto the ortho position of N-benzyl Picolinamides.
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Palladium‐Catalyzed Picolinamide‐Directed Halogenation of ortho C—H Bonds of Benzylamine Substrates.
ChemInform, 2014Co-Authors: Chengxi Lu, Gang He, William A Nack, Shuyu Zhang, Gong ChenAbstract:The presented method features the use of an unique combination of alkali chlorate, bromate, or iodate together with potassium persulfate enabling the installation of the corresponding halogen onto the ortho position of N-benzyl Picolinamides.
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copper catalyzed carboxamide directed ortho amination of anilines with alkylamines at room temperature
ChemInform, 2014Co-Authors: Qiong Li, Gang He, William A Nack, Shuyu Zhang, Zhaoyan Ai, Gong ChenAbstract:Substitution of the Picolinamide moiety by picolinic acid, N-methyl Picolinamide, benzamide, or sulfonamides results in no reaction.
Jinguang Wu - One of the best experts on this subject based on the ideXlab platform.
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structures and spectroscopic characterization of calcium chloride nicotinamide isonicotinamide Picolinamide and praseodymium bromide nicotinamide complexes
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2015Co-Authors: Ye Jiang, Limin Yang, Weihong Li, Yizhuang Xu, Guozhong Zhao, Gaohui Zhang, Jiaer Chen, Xiaoxia Bu, Jinguang WuAbstract:Abstract The coordination structures formed by calcium complexes with nicotinamide (na), isonicotinamide (ina) and Picolinamide (pa) and praseodymium bromide-na are reported. The structures of CaCl2·(C6H6N2O)2·2H2O (Ca-na), CaCl2·(C6H6N2O)2·4H2O (Ca-ina), CaCl2·(C6H6N2O)2·5H2O (Ca-pa) and PrBr3·(C6H6N2O)2·6H2O (PrBr-na) in the solid state have been characterized by X-ray single crystal diffraction, FTIR, FIR, THz and Raman spectroscopies. Carbonyl oxygen of nicotinamide is coordinated to Ca2+, but it is O-monodentate (carbonyl oxygen) and N,O-bidentate ligand (pyridyl nitrogen and carbonyl oxygen) for Pr3+ to form a chain structure in PrBr-na. For isonicotinamide, only carbonyl oxygen atom is coordinated to Ca2+. Pyridyl nitrogen and carbonyl oxygen of Picolinamide are coordinated to Ca2+ to form a five-membered ring structure. The crystal structure and spectroscopic results indicate the differences of the coordination of Ca and Pr ions, the changes of hydrogen bonds and conformation of the ligands induced by complexation. Unlike transition metal ions, Sr2+ or lanthanide ions, Ca2+ is inclined to coordinate to carbonyl oxygen atoms of the ligands.
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the coordination of lanthanide ions with Picolinamide the influence of different anions
CrystEngComm, 2014Co-Authors: Limin Yang, Weihong Li, Yizhuang Xu, Guozhong Zhao, Gaohui Zhang, Jiaer Chen, Jinguang WuAbstract:Four kinds of coordination structures formed by lanthanide–Picolinamide complexes, including [La(C6H6N2O)2(H2O)5]Cl3 (La–pa, Pr–pa, Nd–pa, Sm–pa and Gd–pa), [Er(C6H6N2O)2 (H2O)4]Cl3(H2O) (Er–pa), [Pr(C6H6N2O)2(H2O)5]Br3 (PrBr–pa) and [Nd(C6H6N2O)3(NO3)2] (C6H6N2O)(NO3) (NdN–pa) are reported. The crystal structures in the solid state vary with the change of anions and lanthanide ions as revealed by X-ray single crystal diffraction, FTIR, Raman, FIR and THz spectroscopy. In these crystal structures, the pyridyl nitrogen and carbonyl oxygen of Picolinamide are coordinated to metal ions to form a five-membered ring structure or are hydrogen-bonded. The results indicate the differences in the coordination of different lanthanide ions (the Er ion is special for its small atomic radius), the changes of hydrogen bonds and the conformation of the ligands induced by complexation, and the influence of different anions. When nitrate ions are involved in the coordination structure, the coordination number of lanthanide ions is higher. Chloride and bromine ions do not coordinate to metal ions, so lanthanide bromine and lanthanide chloride–pa complexes have similar structures. The results provide models for the coordination structures of lanthanide ions with ligands that have amide groups.
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synthesis crystal structures and luminescence properties of europium and terbium Picolinamide complexes
Chinese Chemical Letters, 2014Co-Authors: Limin Yang, Weihong Li, Yizhuang Xu, Guozhong Zhao, Gaohui Zhang, Jiaer Chen, Jinguang WuAbstract:Abstract The novel coordination structures of europium and terbium chloride-Picolinamide complexes (EuCl3·(C6H6N2O)2·5H2O, Eu-pa and TbCl3·(C6H6N2O)2·5H2O, Tb-pa) are reported. The crystal structures in the solid state are characterized by X-ray single crystal diffraction, FTIR, Raman, FIR, THz and luminescence spectroscopy. In the crystal structures, the pyridyl nitrogen and carbonyl oxygen atoms in Picolinamide are coordinated to the metal ions to form a five-membered ring structure. The experimental results indicate the similar coordination structures of Eu and Tb-pa complexes and the changes of hydrogen bonds and conformation of the ligands induced by complexation. The results provide models for the coordination structures of lanthanide ions with ligands having amide groups.
Hyeung-geun Park - One of the best experts on this subject based on the ideXlab platform.
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synthesis and optimization of Picolinamide derivatives as a novel class of 11β hydroxysteroid dehydrogenase type 1 11β hsd1 inhibitors
Bioorganic & Medicinal Chemistry Letters, 2015Co-Authors: Hyeung-geun ParkAbstract:Abstract The synthesis and structure–activity relationship of a series of 6-substituted Picolinamide inhibitors of 11β-hydroxysteroid dehydrogenase type 1 are described. The optimization of the left-hand side of lead compound 1 resulted in the discovery of the highly potent, selective, and orally available inhibitor 24, which demonstrated an excellent activity in a mouse ex vivo pharmacodynamic model. Moreover, compound 24 reduced the blood glucose and improved the lipid profiles in ob/ob mice after oral administration.
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Synthesis and biological evaluation of Picolinamides as potent inhibitors of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1).
Bioorganic & Medicinal Chemistry Letters, 2014Co-Authors: Young Ah Shin, Hyeung-geun ParkAbstract:Abstract Synthesis of a series of 6-substituted Picolinamide derivatives and their inhibitory activities against 11β-hydroxysteroid dehydrogenase type 1 are described. Optimization of the initial hit compound, N-cyclohexyl-6-(piperidin-1-yl)Picolinamide (1) from high throughput screening of in-house library resulted in the discovery of the highly potent and metabolically stable compound 25, which was efficacious in a mouse ex vivo pharmacodynamic model and reduced the fasting blood glucose and insulin levels in a HF/STZ mouse model after oral dosing.
