A series of novel π-conjugated bis-propargylic sulfides, selenides, sulfoxides and sulfones have been prepared. In the presence of amine bases these compounds underwent facile isomerization to the corresponding allenes, followed by a tandem cyclization and aromatization of the latter via a diradical intermediate. While the reactions of sulfones and sulfoxides were almost spontaneous and proceeded in practically quantitative yield, the sulfides and selenides exhibited modest reactivity and required more polar solvents to afford the corresponding thiophenes and selenophenes. Some mechanistic studies and DNA cleaving properties are also presented.
|Number of pages||9|
|State||Published - 29 Oct 2001|
Bibliographical noteFunding Information:
The financial support of this study by the Israel Science Foundation is gratefully acknowledged. We are also very much indebted to Dr Shai Rahimipour of the Weizmann Institute of Science for performing the DNA testing.
- Sulfur and selenium compounds