Browsing by Author "Lin, Shu-Fen"

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Diversity-Oriented Synthesis of Angular Bis-benzimidazole Derivatives under Microwave Irradiation
(2009-11-01)
Chen, Chih-Hau
;
Chien, Ming-Hsien
;
Kuo, Min-Liang
;
Chou, Cheng-Ting
;
Lai, Jin-Ji
Pharmaceutically interesting, angular bis-benzimidazoles with three appendages have been synthesized successfully through a diversity-oriented approach with soluble support under microwave irradiation. Polymer immobilized o-phenylenediamine was selectively N-acylated with 2-chloro-3-nitrobenzoic acid in a primary aromatic amino moiety. The obtained amide was cyclized to benzimidazole in an acidic condition, and subsequently nucleophilic aromatic substitution with different amines was performed. Successive reduction, cyclization with various aldehydes and activated isothiocyanates yielded angular biheterocyclic benzimidazoles in good quantities. Reaction progress on polymer support was precisely monitored using the conventional proton NMR spectroscopy. Preliminary screening results showed some of these interesting compounds exhibited moderately to good inhibition against vascular endothelial growth factor receptor 3 (VEGFR-3), which is related to invasion and migration of cancer cells.
Microwave-Assisted Multicomponent Synthesis of Dihydroquinoxalinones on Soluble Polymer Support
(2015-07-01)
Dalvi, Prashant B.
;
Lin, Shu-Fen
;
Paike, Vijaykumar
;
Sun, Chung-Ming
;
應用化學系
A one-pot and two-step reaction of four components, including aldehydes, Fmoc-protected alpha-amino acid, isocyanide, and soluble polymer-supported 4-fluoro-3-amino benzoate ester, was developed for an efficient synthesis of dihydroquinoxalinones under microwave irradiation. Fmoc deprotection followed by intramolecular cyclization of the diamide gave a facile access to novel bicyclic quinoxalin-2-ones. On the basis of this approach, a new route to synthesize this privileged scaffold from the diamide intermediate was designed and accomplished with high yields. Use of multicomponent reaction (MCR) has been shown to display a good functional group tolerance, while the product isolation and purification is straightforward by precipitation and washings. Current library discusses the synthesis and diversification of 21 compounds produced using this strategy.
Traceless synthesis of diketopiperazine fused tetrahydro-beta-carbolines on soluble polymer support
(2011-05-01)
Chanda, Kaushik
;
Chou, Cheng-Ting
;
Lai, Jin-Ji
;
Lin, Shu-Fen
;
Yellol, Gorakh S.
The Pictet-Spengler reaction, using polyethylene glycol immobilized tryptophan ester with a variety of ketones, was achieved by refluxing condition in acidic chloroform. The linear as well as cyclic ketones were employed. All the ketones were reacted within 6-8 h to furnish soluble polymer-supported tetrahydro-beta-carboline in good yields. Further expansion at N-terminus of tetrahydro-beta-carbolines was achieved through a reaction with chloroacetyl chloride. Finally, the 2,5-diketopiperazine skeleton was constructed over a beta-carboline by amination of the resulting N-chloroacetamides and subsequent intramolecular cyclization leading to cleavage of the polymer; constitutes a traceless synthesis of tetracyclic molecular architecture. Significantly, this strategy affords a straightforward and efficient approach for the construction of biological promising molecules with high purity and good yields.