Browsing by Author "Liu, Chia-Chen"

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Design, synthesis and diversification of natural product-inspired hydantoin-fused tetrahydroazepino indoles
(2015-01-01)
Barve, Indrajeet J.
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Dalvi, Prashant B.
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Thikekar, Tushar Ulhas
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Chanda, Kaushik
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Liu, Yu-Li
A facile and efficient synthesis of novel oxo, thio and seleno hydantoin fused tetrahydroazepino [4,5-b] indoles was reported. A naturally occurring iboga class alkaloid inspired seven-membered azepino[4,5-b] indole ring was synthesized as a new scaffold through Pictet-Spengler reaction followed by skeletal rearrangement of the aziridine ring. To improve the efficiency of the synthetic route, the double bond of the rearranged olefinic product 5 was reduced and a privileged hydantoin moiety was constructed on the core system through urea formation using a variety of isocyanates, isothiocyanates and isoselenocyanates followed by intramolecular cyclization to incorporate elements of diversity. The regeneration of the double bond of intermediate 9 afforded hydantoin-fused tetrahydroazepino [4,5-b] indoles.
Diversity-Oriented Synthesis of Coumarin-Linked Benzimidazoles via a One-Pot, Three-Step, Intramolecular Knoevenagel Cyclization
(2017-04-01)
Yao, Po-Hsin Eric
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Kumar, Sunil
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Liu, Yu-Li
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Fang, Chiu-Ping
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Liu, Chia-Chen
Diversity-oriented synthesis of coumarin-linked benzimidazoles from N-(2-aminophenyl)-2-cyanoacetamide was achieved via a one-pot, three-step sequential reaction in excellent. yields. In situ intramolecular cyclization of the cyanoacetamide afforded benzimidazoles which subsequently underwent a Knoevenagel condensation of the 2-cyanome-thylbenzimidazoles with salicylaldehydes promoted by triethylamine to reach the target compounds. An important intermediate, 2-(2-imino-2H-chromen-3-yl)-1H-benzimidazole was characterized by X-ray analysis and further hydrolyzed to 2-(coumarin-3-yl)benzimidazole in acidic condition. Among the synthesized compounds, some were found to be promising inhibitors of porcine kidney D-amino acid oxidase (pkDAO).
Investigating Size Personalization for More Accurate Eye Tracking Glasses
(2017-01-01)
Hsieh, Yi-Yu
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Liu, Chia-Chen
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Wang, Wei-Lin
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Chuang, Jen-Hui
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交大名義發表
Personalized eyewear frame could improve the accuracy of eye tracking. To obtain the personalized frame size (temple length), we propose a new measuring instrument that consists of (i) the hardware, a 3D printed trial frame which has marks but no scales, and (ii) the software, a vision-based measurement which is view invariant. The vision-based measurement has accuracy and precision that are both 0.02 cm, while the trial frame can achieve a precision of 0.17 cm for secure wearing. Moreover, dispersion up to 2.56 cm is obtained among the personalized frame sizes for just a fairly small group of users, indicating the importance of having such a personalized measurement system.