Tri- and tetracyclic azepine derivatives by thermally induced cyclization of aminoallenes and semicyclic 2-dienamines

The thermal isomerization of the 3,3-dimethylindoline-derived allenes, prepared through the organocuprate addition to 2-(phenylethynyl)-3,3-dimetthyl-1-methylindolium triflate, affords tetracyclic azepine derivatives. The spontaneous tautomerization of corresponding aminoallenes led to the formation of the semicyclic 2-amino 1,3-dienes.