Browsing by Author "Tseng, Chih-Chung"

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Chemical Synthesis of the Englerins
(2012-01-02)
Pouwer, Rebecca H.
;
Richard, Jean-Alexandre
;
Tseng, Chih-Chung
;
Chen, David Y. -K.
;
應用化學系
In the long lasting battle against cancer, Nature sometimes gives a helping hand to researchers to find new drugs for the treatment of diseases and improvement of patients' well-being. Englerin A has emerged as a promising anticancer candidate as well as being an exciting synthetic challenge for organic chemists. This focus review summarizes the total syntheses reported to date and the synthetic approaches toward analogues of this fascinating natural product.
Light Fluorous-Tagged Traceless One-Pot Synthesis of Benzimidazoles Facilitated by Microwave Irradiation
(2012-06-01)
Tseng, Chih-Chung
;
Tasi, Cheng-Hsun
;
Sun, Chung-Ming
;
應用化學系
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Department of Applied Chemistry
A novel protocol for rapid assemble of benzimidazole framework has been demonstrated. This method incorporated with light fluorous-tag provides a convenient method for diversification of benzimidazoles and for easy purification via fluorous solid-phase extraction (F-SPE) in a parallel manner. The key transformation of this study involves in situ reduction of aromatic nitro compound, amide formation, cyclization and aromatization promoted by microwave irradiation in a one-pot fashion. The strategy is envisaged to be applied for the establishment of drug-like small molecule libraries for high throughput screening.
Microwave-Assisted Linear Approach Toward Highly Substituted Benzo[d]oxazol-5-yl-1H-benzo[d]imidazole on Ionic Liquid Support
(2012-02-01)
Chanda, Kaushik
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Maiti, Barnali
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Tseng, Chih-Chung
;
Sun, Chung-Ming
;
應用化學系
A novel and efficient diversity-oriented synthetic approach was employed to access the benzo[d]oxazol-5-yl-1H-, benzo[d]imidazole on ionic liquid support, which helps to absorb microwave irradiation. In this paper, we successfully coupled 4- hydroxy-3-nitrobenzoic acid onto ionic liquid-immobilized o-phenylehediaimine which subsequently underwent an acid mediated, ring closure reaction leading to benzimidazole derivatives. After hydrogenation of the nitro group to an amine, the resulting ionic liquid conjugate was reacted with 1,1-thiocarbonyldiimidazols to yield an ionic liquid tagged-benzoxazol, Final skeletal diversity of the present scaffold was further achieved by S-alkylation with alkyl and aryl bromides. The benzo[d]oxazol-5-, yl-1H-benzo[d]imidazole was finally cleaved smoothly from the ionic liquid support with sodium methoxide in methanol under microwave irradiation. This methodology has provided access to a small, diverse library by straightforward and simple operations and could be applied readily in various drug discovery programs.
Multicomponent Solvent-Free Synthesis Of Benzimidazolyl Imidazo[1,2-a]-pyridine Under Microwave Irradiation
(2013-06-01)
Maiti, Barnali
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Chanda, Kaushik
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Selvaraju, Manikandan
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Tseng, Chih-Chung
;
Sun, Chung-Ming
A novel one-pot, three-component reaction employing variously substituted benzimidazole-linked amino pyridines, aldehydes, and isonitriles catalyzed by scandium(III) triflate under solvent-free conditions were accomplished. This new synthetic methodology facilitates the rapid generation of intricate molecular frameworks in three-dimensional fashion leading to benzinaidazole-imidazo [1,2-a] pyridines. This approach is envisioned as an environmentally benign process and a simple operation to the biological interesting compounds. The present synthetic sequence permits the introduction of three points of structural diversity to expand chemical space with high purity and excellent yields.
Traceless polymer-supported divergent synthesis of quinoxalinones by microwave irradiation
(2012-05-06)
Shen, Chien-Hung
;
Tseng, Chih-Chung
;
Tasi, Cheng-Hsun
;
Shintre, Suhas A.
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Chen, Li-Hsun
A novel protocol for rapid assemble of quinoxalinones framework has been demonstrated. This method incorporated with soluble polymer support provides a convenient approach for diversification of heterocyclic compounds and for easy purification via facile precipitation from reaction matrix. The key transformation of this study involves in situ reduction of aromatic nitro compound, tandem lactamization concomitant with traceless cleavage of the polymer support under microwave irradiation in a one-pot fashion. Moreover, forward synthetic routes were introduced to maximize complexity of the master intermediate on which further chemical elaboration was applied. The strategy is envisaged to apply for establishment of drug-like small-molecule libraries for high-throughput screening. (C) 2012 Elsevier Ltd. All rights reserved.
Traceless polymer-supported divergent synthesis of quinoxalinones by microwave irradiation
(2012-05-06)
Shen, Chien-Hung
;
Tseng, Chih-Chung
;
Tasi, Cheng-Hsun
;
Shintre, Suhas A.
;
Chen, Li-Hsun
A novel protocol for rapid assemble of quinoxalinones framework has been demonstrated. This method incorporated with soluble polymer support provides a convenient approach for diversification of heterocyclic compounds and for easy purification via facile precipitation from reaction matrix. The key transformation of this study involves in situ reduction of aromatic nitro compound, tandem lactamization concomitant with traceless cleavage of the polymer support under microwave irradiation in a one-pot fashion. Moreover, forward synthetic routes were introduced to maximize complexity of the master intermediate on which further chemical elaboration was applied. The strategy is envisaged to apply for establishment of drug-like small-molecule libraries for high-throughput screening. (C) 2012 Elsevier Ltd. All rights reserved.