<i>N</i>-Vinyl- and <i>C</i>-Vinylpyrroles from Azafulvenium Methides. Flash Vacuum Pyrolysis Route to 5-Oxo-5<i>H</i>-pyrrolizines and 1-Azabenzo[<i>f</i>]azulenes
作者:Teresa M. V. D. Pinho e Melo、Maria I. L. Soares、António M. d'A. Rocha Gonsalves,、José A. Paixão、Ana Matos Beja、Manuela Ramos Silva
DOI:10.1021/jo050480i
日期:2005.8.1
1-Azafulvenium methides, generated from pyrrolo[1,2-c]thiazole-2,2-dioxides' thermal extrusion of sulfur dioxide, led to the synthesis of functionalized pyrroles. The intramolecular trapping of these transient 8π 1,7-dipoles in pericyclic reactions, namely sigmatropic [1,8]H shifts and 1,7-electrocyclization, allowed the synthesis of N-vinylpyrroles and C-vinylpyrroles which, under flash vacuum pyrolysis
由吡咯并[1,2 - c ]噻唑-2,2-二氧化物对二氧化硫的热挤压生成的1-氮杂富烯基甲基化物导致了官能化吡咯的合成。这些瞬态8π1,7-偶极在周环反应中的分子内捕获,即σ[1,8] H位移和1,7-电环化,可以合成N-乙烯基吡咯和C-乙烯基吡咯,在快速真空热解条件下分别被转化为5-氧代-5 H-吡咯嗪或4-氧代-1,4-二氢-1-氮杂-苯并[ f ] azulenes。这些杂环也可以直接从吡咯并[1,2 - c ]噻唑2,2-二氧化物的FVP获得。新型6-氧代环戊的合成及X射线结构[ b还报道了]吡咯衍生物。