Strychnos 1990 - 2004 - Crops for the Future
Strychnos 1990 - 2004 - Crops for the Future
Strychnos 1990 - 2004 - Crops for the Future
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Author<br />
Title<br />
Year<br />
Source title<br />
Reference<br />
Padwa, A. and A. G. Waterson<br />
The thionium/n-acyliminium ion cyclization cascade as a strategy <strong>for</strong> <strong>the</strong> syn<strong>the</strong>si<br />
2000<br />
Tetrahedron<br />
56(52): 10159-10173<br />
Abstract<br />
A series of amidosulfoxides were prepared by <strong>the</strong> addition of thiophenol to <strong>the</strong> appropriate alkenoic<br />
acid pi -bond, and this was followed by reaction of <strong>the</strong> in situ generated acyl chloride with 3,4-<br />
dimethoxyphenethyl amine. The silicon-induced Pummerer reaction of <strong>the</strong>se amidosulfoxides was<br />
carried out using 1-(dimethyl-tert-butylsiloxy)-1-methoxyethylene in dry acetonitrile in <strong>the</strong> presence<br />
of a catalytic amount of ZnI2 and led to <strong>the</strong> very clean <strong>for</strong>mation of 2-thiophenyl substituted lactams.<br />
Iminium ion-aromatic pi -cyclization was accomplished by treatment of <strong>the</strong> initially <strong>for</strong>med<br />
thiophenyl lactams with BF3.2AcOH which resulted in <strong>the</strong> generation of an N-acyliminium ion.<br />
Cyclization of <strong>the</strong> iminium ion onto <strong>the</strong> te<strong>the</strong>red aromatic ring led to various azapolycyclic ring<br />
systems. A related cyclization sequence also occurred with amidosulfoxides that possess simple<br />
olefinic te<strong>the</strong>rs. The method was applied toward <strong>the</strong> syn<strong>the</strong>sis of a member of <strong>the</strong> protoberberine<br />
alkaloid family. (C) 2000 Elsevier Science Ltd. All rights reserved.<br />
Author<br />
Title<br />
Year<br />
Source title<br />
Reference<br />
Abstract<br />
Penelle, J., M. Tits, P. Christen, J. Molgo, V. Brandt, M. Frederich and L. Angeno<br />
Quaternary indole alkaloids from <strong>the</strong> stem bark of <strong>Strychnos</strong> guianensis<br />
2000<br />
Phytochemistry<br />
53(8): 1057-1066<br />
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