- Ethynylation of aryl halides by a modified Suzuki reaction: Application to the syntheses of combretastatin A-4, A-5 and lunularic acid
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On treatment with trimethyl borate sodium acetylide undergoes a palladium-catalyzed cross coupling with functionalized aryl halides or triflates in reasonable to good yields. The ethynylarenes thus obtained serve as building blocks for the formation of the highly effective tubulin polymerization inhibitors combretastatin A-4 (1) and A-5 (2) as well as for the synthesis of the plant-growth regulator lunularic acid (36). VCH Verlagsgesellschaft mbH, 1996.
- Fuerstner, Alois,Nikolakis, Katharina
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p. 2107 - 2113
(2007/10/03)
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- Antineoplastic Agents. 291. Isolation and Synthesis of Combretastatins A-4, A-5, and A-6
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The antineoplastic constituents of Combretum caffrum (Eckl. and Zeyh) Kuntze (Combretaceae family), a species indigenous to South Africa, have been investigated.Subsequently we isolated a series of closely related bibenzyls, stilbenes, and phenanthrenes from C. caffrum.Some of the stilbenes proved to be potent antimitotic agents which inhibited both tubulin polymerization and the binding of colchicine to tubulin.Combretastatin A-4 has been shown to be the most potent cancer cell growth inhibitor of the series.Presently this cis-stilbene is the most effective inhibitor of colchicine binding to tubulin and the simplest natural product yet described with such potent antitubulin effects.Combretastatin A-4, A-5, and A-6 were also found to inhibit growth of Neisseria gonorrhoeae.Details of the isolation and syntheses of combretastatins A-4 (2a), A-5 (2c), and A-6 (3a) have been described.
- Pettit, George R.,Singh, Sheo Bux,Boyd, Michael R.,Hamel, Ernest,Pettit, Robin K.,et al.
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p. 1666 - 1672
(2007/10/02)
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