Browsing by Author "Chen, I-Chia"

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A Combined Tamaru Allylation/Olefin Cross-Metathesis Approach for the Total Syntheses of (+/-)-Paniculidine B, (+/-)-Paniculidine C, and 2-Methylcarbazole
(2018-03-01)
Tseng, Yi-Lun
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Liang, Min-Chieh
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Chen, I-Chia
;
Wu, Yen-Ku
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應用化學系
A concise approach to the total syntheses of racemic paniculidines B and C is described. The route features a combined Tamaru allylation/olefin cross-metathesis sequence for the regiocontrolled synthesis of prenylindole intermediates. In addition, we report a transformation of the prenylated indole into 2-methylcarbazole catalyzed by sulfonic acid-functionalized silica gel.
A Rapid SNAP-Tag Fluorogenic Probe Based on an Environment-Sensitive Fluorophore for No-Wash Live Cell Imaging
(2014-10-01)
Liu, Tao-Kai
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Hsieh, Pei-Ying
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Zhuang, Yu-De
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Hsia, Chi-Yang
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Huang, Chi-Ling
One major limitation of labeling proteins with synthetic fluorophores is the high fluorescence background, which necessitates extensive washing steps to remove unreacted fluorophores. In this paper, we describe a novel fluorogenic probe based on an environment-sensitive fluorophore for labeling with SNAP-tag proteins. The probe exhibits dramatic fluorescence turn-on of 280-fold upon being labeled to SNAP-tag. The major advantages of our fluorogenic probe are the dramatic fluorescence turn-on, ease of synthesis, high selectivity, and rapid labeling with SNAP-tag. No-wash labeling of both intracellular and cell surface proteins was successfully achieved in living cells, and the localization of these proteins was specifically visualized.
Autoionizing Rydberg series (np ', nf ') of Ar investigated by stepwise excitations with lasers and synchrotron radiation
(2008-08-01)
Lee, Yin-Yu
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Dung, Tzan-Yi
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Hsieh, Re-Ming
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Yuh, Jih-Young
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Song, Yen-Fang
Synchrotron radiation is used to excite Ar to the intermediate states 3p(1/2)(5) (3d '[3/2](1), 5d '[3/2](1), 5s '[1/2](1,) 7s '[1/2](1)) and 3p(3/2)(5) (6d[1/2](1), 6d[3/2](1), 8s[3/2](1)), then excited by lasers to the autoionizing Rydberg series 3p(1/2)(5) np ' ([1/2](0,1), [3/2](1,2)) and nf '[5/2](2). For the intermediate states of 5s ', 7s ', and 8s, the np ' ([1/2](0) and [3/2](2)) series are observed with high intensity but not the np ' ([1/2](1) and [3/2](1)) series when the polarization vectors of two light beams are in parallel; but when they are in orthogonal, the np '[1/2](0) series disappears, the np '[3/2](2) intensity remains, and the np ' ([1/2](1) and [3/2](1)) series show up strongly. The intensity distribution of the np ' series strongly depends on the intermediate state. The spectra of the np ' series are assigned according to their intensity variation with the polarization vectors. The quantum defects determined for the series np '[1/2](0)(n=11-57), np '[312](2)(n=11-65), np '[3/2](1)(n=11-31), and nf '[5/2](2)(n=9-74) are 1.611 +/- 0.011, 1.683 +/- 0.013, 1.688 +/- 0.010, and 0.016 +/- 0.005, respectively. Our values are in excellent agreement with theoretical prediction. The spectral line shapes of autoionizing Rydberg states are analyzed with a Beutler-Fano profile. Reduced autoionization linewidths for the np '[1/2](0)(n= 11-16) series vary in the range 2549-4145 cm(-1), and the nf '[5/2](2)(n=9-11) series in 186-247 cm(-1) in reasonable agreement with theoretical prediction.
Palladium-catalyzed alpha-arylation of indolin-3-ones
(2020-04-30)
Chang, Yu-Hsuan
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Peng, Wan-Ling
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Chen, I-Chia
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Hsu, Hsin-Yun
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Wu, Yen-Ku
A method for the catalytic alpha-arylation of indolin-3-ones was developed. The catalytic system comprising Pd(dba)(2) and PAd(3) was found to be optimal for the transformation. The protocol features broad functional group compatibility in that a range of arylated indoxyl derivatives bearing a fully substituted carbon center was synthesized with high efficiency. A preliminary bioassay study revealed that the selected indole-substituted indolin-3-ones exhibit favorable cytotoxic activities against HCT-116 cancer cell line.
Temperature-Controlled Thiation of alpha-Cyano-beta-Alkynyl Carbonyl Derivatives for De Novo Synthesis of 2-Aminothiophenes and Thieno[2,3-c]isothiazoles
(2018-12-07)
Kao, Tzu-Ting
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Peng, Bo-Kai
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Liang, Min-Chieh
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Lee, Chia-Jui
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Chen, I-Chia
Making use of temperature-controlled thiation as a key operation, a simple route to 2-aminothiophenes or thieno[2,3-c]isothiazoles has been newly developed wherein the 2-aminothiophene nucleus was formed through an initial formation of thioamide followed by a 5-exo-dig addition to the tethered alkyne; however, under harsher thermal conditions, excess sulfur-transferring reagents enabled further oxidative thiation to generate the corresponding thieno[2,3-c]isothiazoles.