A novel synthesis of thiophenes from allenic sulfones involving α,β-unsaturated sulfines as intermediates
作者:S. Braverman、P.F.T.M. van Asten、J.B. van der Linden、B. Zwanenburg
DOI:10.1016/s0040-4039(00)79399-3
日期:1991.7
A new method for the synthesis of α,β-unsaturatedsulfines by a Peterson alkylidenation of sulfur dioxide is described. The required α-silyl carbanions are generated by heteroconjugate addition of alkyllithium to α-trimethylsitylated aIlenic sulfones. The conjugated vinylsulfines thus prepared undergo a rapid and unprecedented cycloaromatization to thiophene derivatives. A mechanism for this remarkable