Synthesis of thiophenes from allenyl sulfones involving α,β-unsaturated sulfines as intermediates
作者:Johannes B. van der Linden、Peter F. T. M. van Asten、Samuel Braverman、Binne Zwanenburg
DOI:10.1002/recl.19951140203
日期:——
The synthesis of thiophenes starting fromallenylsulfones, via intermediate formation of α,β-unsaturatedsulfines, is described. The allenylsulfones were synthesized by a [2,3]-sigmatropic rearrangement of appropriately substituted prop-2-ynyl sulfinates. Treatment of the allenylsulfones with n-butyllithium and chlorotrimethylsilane gave α-silylated allenylsulfones in almost quantitative yield
The preparation and Claisen rearrangement of highly substitutedallyl vinyl ethers is described. It is demonstrated that the thermal and anionic versions of the Claisen rearrangement are capable of creating vicinal quaternary centers.
Synthesis of 3-(Arylsulfonyl)-3-pyrrolines from Allenyl Sulfonamides by Silver Ion Catalysis
作者:Rama Rao Tata、Chencheng Fu、Steven P. Kelley、Michael Harmata
DOI:10.1021/acs.orglett.8b02440
日期:2018.9.21
Treatment of allenyl sulfonamides with catalytic amounts of silver fluoride in acetonitrile at reflux afforded the corresponding 3-sulfonyl-3-pyrrolines in excellent yields by intramolecular hydroamination via a 5-endo-trig cyclization. The starting allenyl sulfonamides were prepared by lithiation of allenic sulfones and trapping with various N-sulfonylimines.