Thermal oligomerisation of aryl isocyanides: formation of pyrazino[1,2-a:4,5-a′]diindoles and indigo diarylimines
作者:Jan C. A. Boeyens、Leanne M. Cook、Yunxiang Ding、Manuel A. Fernandes、David H. Reid
DOI:10.1039/b302340k
日期:——
The aryl isocyanides 1â4 are converted at 150 °C into the hexameric pyrazino[1,2-a:4,5-aâ²]diindoles 15â19. 4-Fluorophenyl isocyanide, when heated at 135 °C, gave the hexamer 19 and the tetrameric indigo di-arylimine 9, and when kept at ambient temperature gave mainly the tetramer 9 in low yield. The structures of the hexamer 19 and the tetramer 9 were established by X-ray crystallography. Mechanisms are proposed for the oligomerisation reactions.