Browsing by Author "Chung, Tsai-Wen"

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A Novel Mechanistic Study on Ultrasound-Assisted, One-Pot Synthesis of Functionalized Benzimidazo[2,1-b]quinazolin-1(1H)-ones
(2016-03)
Chen, Li-Hsun
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Chung, Tsai-Wen
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Narhe, Bharat D.
;
Sun, Chung-Ming
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應用化學系
Ultrasound-assisted synthesis of benzimidazo[2,1-b]quinazolin-1(1H)-ones was achieved via piperidine-catalyzed three-component reaction of 2-aminobenzimidazoles, an aromatic aldehyde, and 1,3-dione in aqueous isopropanol. This mechanism was first suspected following our identification of unusual reaction intermediates in a one-pot reaction. An unprecedented coupling reaction, it involved a nucleophilic attack by 2-aminobenzimidazole on in situ generated Michael adduct, followed by electrocyclic ring formation reaction. In contrast to the commonly accepted mechanism, that the direct reaction of 2-amino benzimidazole with a Knoevenagel adduct cannot deliver target compounds.
Exploring a sulfone linker utilizing trimethyl aluminum as a cleavage reagent: solid-phase synthesis of sulfonamides and ureas
(2012-08-01)
Chung, Tsai-Wen
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Chen, Chih-Hau
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Lin, Chu-Chung
;
Wu, Hsien-Jen
;
Sun, Chung-Ming
A novel and efficient cleavage reagent, trimethyl aluminum, for traceless sulfinate-functionalized resin has been developed. The synthesis of sulfonamide and urea derivatives via a traceless solid-phase sulfone linker strategy through six synthetic steps comprising utilization of trimethyl aluminum as a novel cleavage reagent was also established. An insight of the plausible mechanism of the cleavage reaction was discussed.
Multicomponent Synthesis of Functionalized Tetrahydroacridinones: Insights into a Mechanistic Route
(2015-11-06)
Chung, Tsai-Wen
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Narhe, Bharat D.
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Lin, Chun-Cheng
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Sun, Chung-Ming
;
應用化學系
A mechanistic study of three-component reactions of various aromatic amines with a number of aldehydes and 1,3-diones was achieved. The unprecedented reaction involved a nucleophilic attack of an aromatic amine on the in situ generated Michael adduct intermediate followed by six-electron ring cyclizations. It is contrary to the common belief that advocates involvement of coupling reactions between a Knoevenagel adduct and an aromatic amine to deliver substituted tetrahydroacridinones.
Novel cyclization of bis-Boc-guanidines: expeditive traceless synthesis of 1,3,5-oxadiazinones under microwave conditions
(2010)
Yellol, Gorakh S.
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Chung, Tsai-Wen
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Sun, Chung-Ming
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應用化學系
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Department of Applied Chemistry
A novel intramolecular cyclization was discovered during the reaction of soluble polymer supported bis-Boc-guanidines with amines under microwave irradiation, leading to an oxadiazinone skeleton. The cyclized polymer conjugates have been further utilized to generate substituted 1,3,5-oxadiazinones by a traceless synthesis.
Qualitative analysis of the fluorophosphonate-based chemical probes using the serine hydrolases from mouse liver and poly-3-hydroxybutyrate depolymerase (PhaZ) from Bacillus thuringiensis
(2012-11-01)
Huang, Yi-Long
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Chung, Tsai-Wen
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Chang, Chia-Mao
;
Chen, Chih-Hau
;
Liao, Chen-Chung
The serine hydrolase family consists of more than 200 members and is one of the largest enzyme families in the human genome. Although up to 50 % of this family remains unannotated, there are increasing evidences that activities of certain serine hydrolases are associated with diseases like cancer neoplasia, invasiveness, etc. By now, several activity-based chemical probes have been developed and are applied to profile the global activity of serine hydrolases in diverse proteomes. In this study, two fluorophosphonate (FP)-based chemical probes were synthesized. Further examination of their abilities to label and pull down serine hydrolases was conducted. In addition, the poly-3-hydroxybutyrate depolymerase (PhaZ) from Bacillus thuringiensis was demonstrated as an appropriate standard serine hydrolase, which can be applied to measure the labeling ability and pull-down efficiency of FP-based probes. Furthermore, mass spectrometry (MS) was used to identify the serine residue that covalently bonded to the active probes. Finally, these FP-based probes were shown capable of establishing the serine hydrolase profiles in diverse mouse tissues; the serine hydrolases pulled down from mouse liver organ were further identified by MS. In summary, our study provides an adequate method to evaluate the reactivity of FP-based probes targeting serine hydrolases.
Telescoped Synthesis of 2-Acyl-1-aryl-1,2-dihydroisoquinolines and Their Inhibition of the Transcription Factor NF-kappa B
(2015-08-01)
Chung, Tsai-Wen
;
Hung, Yi-Tzu
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Thikekar, Tushar
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Paike, Vijaykumar V.
;
Lo, Fu Yuan
A sequential single-flask multicomponent reactions is highly effective for the synthesis of 1,2-dihydroisoquinolines through amidealkylation from intermediate N-acylisoquinolinium salts under mild conditions. N-Acylisoquinolinium ions and trichloromethyl-1-(1H-indol-3-yl)isoquinoline-2(1H)-carboxylate have demonstrated their reactivity toward aromatic and aliphatic pi-nucleophiles. One of the 1,2-dihydroisoquinoline derivatives was found to be a potent inhibitor for transcription factor NF-kappa B by blocking I kappa B alpha degradation, p65 nuclear translocation, and NF-kappa B DNA binding in TNF-alpha-induced NIH 3T3 cells.