Browsing by Author "Hsu, Wei-Shun"

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A Telescoping Synthesis of Chimeric Polyheterocycles through a Piperidine-Mediated Multicomponent Reaction
(2013-04-01)
Lee, Chia-Hsin
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Hsu, Wei-Shun
;
Chen, Chih-Hau
;
Sun, Chung-Ming
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應用化學系
A new piperidine-catalyzed Groebke-Bienayme-Blackburn (GBB) multicomponent reaction of 2-aminobenzimidazoles, methyl 2-formylbenzoate, and isocyanides has been explored. A facile and straightforward postmodification leads to isoquinolinone-embedded imidazo[1,2-a]benzimidazoles. Insight into a plausible mechanism is discussed and supported by X-ray crystal structure analysis.
One pot three component reaction for the rapid synthesis of pyrrolo[1,2-a]benzimidazoles
(2013-05-01)
Hsu, Wei-Shun
;
Paike, Vijaykumar
;
Sun, Chung-Ming
;
應用化學系
;
Department of Applied Chemistry
An efficient strategy for the synthesis of pyrrolo[1,2-]-benzimidazole (PBI) linked to an ionic liquid (ILs) as a soluble support under microwave irradiation was explored. The key intermediate benzimidazoles were synthesized via N-acylation followed by cyclodehydration of IL-supported methyl-3-amino-4-(isobutylamino) benzoate. The synthesis of the IL-bound PBI was performed by one-pot three-component condensation under microwave dielectric heating, which involved a Knoevenagel condensation and a [4+1]-cycloaddition reaction. The reaction was monitored directly by means of H NMR. All final products were obtained in good yield and high purity after precipitation.
Synthesis of Aminofuran-Linked Benzimidazoles and Cyanopyrrole-Fused Benzimidazoles by Condition-Based Skeletal Divergence
(2017-07-01)
Hsu, Wei-Shun
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Tsai, Min-Huan
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Barve, Indrajeet J.
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Yellol, Gorakh S.
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Sun, Chung-Ming
A condition-based skeletal divergent synthesis was explored to achieve skeletal diversity in two component condensation reaction. Cyanomethyl benzimidazole was reacted with alpha-bromoketone under thermal conditions to furnish 2-aminofuranyl-benzimidazoles, while the same reaction afforded 3-cyano-benzopyrrolo-imidazoles under microwave irradiation. Two nonequivalent nucleophilic centers on benzimidazole moiety were manipulated elegantly by different reaction conditions to achieve the skeletal diversity.