来自氮杂富烯亚甲基鎓盐的N-乙烯基和C-乙烯基吡咯。通过快速真空热解途径合成5-氧代-5H-吡咯嗪和1-氮杂苯并[f]薁。

N-Vinyl- and C-vinylpyrroles from azafulvenium methides. flash vacuum pyrolysis route to 5-Oxo-5H-pyrrolizines and 1-azabenzo[f]azulenes.

作者信息

Pinho e Melo Teresa M V D, Soares Maria I L, Gonsalves António M d'A Rocha, Paixão José A, Beja Ana Matos, Silva Manuela Ramos

机构信息

Departamento de Química, Universidade de Coimbra, 3004-535 Coimbra, Portugal.

出版信息

J Org Chem. 2005 Aug 19;70(17):6629-38. doi: 10.1021/jo050480i.

DOI:10.1021/jo050480i

PMID:16095280

Abstract

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 8pi 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 conditions, are converted into 5-oxo-5H-pyrrolizines or 4-oxo-1,4-dihydro-1-aza-benzo[f]azulenes, respectively. These heterocycles can also be obtained directly from FVP of pyrrolo[1,2-c]thiazole 2,2-dioxides. The synthesis and X-ray structure of a new 6-oxocyclopenta[b]pyrrole derivative is also reported.

摘要

由吡咯并[1,2 - c]噻唑 - 2,2 - 二氧化物热解挤出二氧化硫生成的1 - 氮杂富烯鎓甲基化物，导致了功能化吡咯的合成。这些瞬态8π 1,7 - 偶极子在周环反应中的分子内捕获，即[1,8]氢迁移和1,7 - 电环化，使得N - 乙烯基吡咯和C - 乙烯基吡咯得以合成，在快速真空热解条件下，它们分别转化为5 - 氧代 - 5H - 吡咯嗪或4 - 氧代 - 1,4 - 二氢 - 1 - 氮杂 - 苯并[f]薁。这些杂环也可以直接从吡咯并[1,2 - c]噻唑2,2 - 二氧化物的快速真空热解中获得。还报道了一种新的6 - 氧代环戊并[b]吡咯衍生物的合成及X射线结构。