Base catalyzed rearrangement of π-conjugated sulfur and selenium bridged propargylic systems
作者:Samuel Braverman、Yossi Zafrani、Hugo E Gottlieb
DOI:10.1016/s0040-4020(01)00923-1
日期:2001.10
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