The 3,3-dimethylindoline-derived allenes 5 are conveniently prepared by organocuprate addition to 2-(phenylethynyl)-3,3-dimethyl-1-methylindolium triflate 4. Their thermal isomerization affords tetracyclic azepine derivatives 6. The semicyclic 2-amino 1,3-dienes 11, formed by spontaneous tautomerization of the corresponding aminoallenes, are transformed by thermal reaction into either tricyclic azepine derivatives 13 or benzothiophene-annelated azaheterocycles 14 and 15, depending on the ring size of the enamine moiety and the (hetero)aryl group at C-4 of the 2-dienamine.

Conjugate addition of organocuprates to the 2‐ethynyl‐substituted cyclic iminium triflates 3 generates aminoallenes which tautomerize immediately to semicyclic 2‐amino‐1,3‐dienes (6, 8) or exocyclic 1‐amino‐1,3‐dienes (9, 10) with the enamine function incorporated into or attached to a 5‐, 6‐, or 7‐membered ring. In those cases where tautomeric equilibria between the two aminodiene species are possible, the five‐membered ring exists virtually exclusively with an exocyclic enamine double bond, but the six‐membered ring prefers the exocyclic form. The seven‐membered ring can accomodate both forms quite well.

Tri-and Tetracyclic Azepine Derivatives by Thermally Induced Cyclization of Aminoallenes and Semicyclic 2-Dienamines.-It offers an efficient route to tri-and tetracyclic azepines. The outcome of the cyclization of 2-dienamines strongly depends on the ring size of the enamine moiety and the nature of the aryl substituent at C-2'. -(REINHARD, R.; GLASER, M.; NEUMANN, R.; MAAS, G.; J.

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