Unprecedented intramolecular [3 + 2] cycloadditions of azido-ketenimines and azido-carbodiimides. Synthesis of indolo[1,2-a]quinazolines and tetrazolo[5,1-b]quinazolines
作者:Mateo Alajarin、Baltasar Bonillo、Maria-Mar Ortin、Raul-Angel Orenes、Angel Vidal
DOI:10.1039/c1ob05745f
日期:——
N-(2-Azidomethyl)phenyl ketenimines and N-(2-azidomethyl)phenyl-N′-alkyl(aryl) carbodiimides undergo, under mild thermal conditions, intramolecular [3 + 2] cycloaddition reactions between the azido group and either the CC or the distal CN double bonds of the ketenimine and carbodiimide functions respectively. The reaction products are indolo[1,2-a]quinazolines and/or indolo[2,1-b]quinazolines in the
N-(2-叠氮甲基)苯基酮亚胺和N-(2-叠氮甲基)苯基-N'-烷基(芳基)碳二亚胺在温和的热条件下发生叠氮基与C之间的分子内[3 + 2]环加成反应C或C的远端C N双键酮亚胺和碳二亚胺的功能。反应产物是吲哚并[1,2一]喹唑啉和/或吲哚并[2,1- b ]喹唑啉在叠氮基-乙烯酮亚胺的情况下,和四唑并[5,1- b在叠氮基的碳二亚胺的情况下]喹唑啉。两类吲哚并喹唑啉的形成意味着叠氮和酮亚胺官能团之间非分离的推定的[3 + 2]环加合物向后挤压二氮,而叠氮-碳二亚胺时,最初的环加合物四唑并喹啉已被干净地分离出来。并通过热诱导二氮挤出进一步转化为2-氨基喹唑啉。