Chuan Gee Lim

Publications (3)6.08 Total impact

• Source

  Available from: Azhar Ariffin

  Article: Cyclization vs. cyclization/dimerization in o-amidostilbene radical cation cascade reactions: the amide question.

  Chin Hui Kee, Azhar Ariffin, Khalijah Awang, Ibrahim Noorbatcha, Koichi Takeya, Hiroshi Morita, Chuan Gee Lim, Noel Francis Thomas
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  ABSTRACT: The n-butyramido, isobutyramido, benzamido, and furancarboxamido functions profoundly modulate the electronics of the stilbene olefinic and NH groups and the corresponding radical cations in ways that influence the efficiency of the cyclization due presumably to conformational and stereoelectronic factors. For example, isobutyramido- stilbene undergoes FeCl(3) promoted cyclization to produce only indoline, while n-butyramidostilbene, under the same conditions, produces both indoline and bisindoline.
  Molecules 01/2011; 16(9):7267-87. · 2.39 Impact Factor
• Article: Challenges associated with the synthesis of unusual o-carboxamido stilbenes by the Heck protocol: Intriguing substituent effects, their toxicological and chemopreventive implications.

  Chin Hui Kee, Azhar Ariffin, Khalijah Awang, Koichi Takeya, Hiroshi Morita, Salmaan Inayat Hussain, Kok Meng Chan, Pauline J Wood, Michael D Threadgill, Chuan Gee Lim, Seikweng Ng, Jean Frédéric F Weber, Noel F Thomas
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  ABSTRACT: The syntheses of fourteen unusual o-carboxamido stilbenes by the Heck protocol revealed surprising complexity related to intriguing substituent effects with mechanistic implications. The unexpected cytotoxic and chemopreventive properties also seem to be substituent dependent. For example, although stilbene 15d (with a 4-methoxy substituent) showed cytotoxicity on HT29 colon cancer cells with an IC(50) of 4.9 μM, the 3,4-dimethoxy derivative (15c) is inactive. It is interesting to observe that the 3,5-dimethoxy derivative (15e) showed remarkable chemopreventive activity in WRL-68 fetal hepatocytes, surpassing the gold standard, resveratrol. The resveratrol concentration needed to be 5 times higher than that of 15e to produce comparable elevation of NQO1.
  Organic & Biomolecular Chemistry 10/2010; 8(24):5646-60. · 3.70 Impact Factor
• Article: A FeCl3-promoted highly atropodiastereoselective cascade reaction: synthetic utility of radical cations in indolostilbene construction

  Kartini Ahmad, Noel F. Thomas, Mat Ropi Mukhtar, Ibrahim Noorbatcha, Jean-Frederic Faizal Weber, Mohd Azlan Nafiah, Saraswati S. Velu, Koichi Takeya, Hiroshi Morita, Chuan-Gee Lim, A. Hamid A. Hadi, Khalijah Awang
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  ABSTRACT: The FeCl3-promoted oxidative cyclization/coupling of acetamidostilbenes possessing 3-methoxy, 4-methoxy and 3,5-methoxy substitutions (21), (22) and (23) is described. Only 3,5-substitution gave rise to novel indolostilbenes, each possessing two stereogenic axes (axially chiral but racemic dimers (39) and (40)). The 4-methoxy substituted acetamidostilbenes, by contrast, yielded the bisindoline dimer (36).Graphical abstract
  Tetrahedron. 65(7):1504-1516.