Cyclohexanones have been converted into a variety of bicyclic azaheterocycles of different oxidation level via a sequence of reactions involving (a) imination, (b) alpha-alkylation with N,N-disilyl-protected omega-bromoamines, (c) transimination, (d) alpha-chlorination of the resulting bicyclic imines and (e) dehydrochlorination and/or dehydrogenation. Appropriate choice of the reaction conditions selectively led the reactions to indoles, 7-chloroindoles, 7-chloroindolines, 4,5,6,7-tetrahydroindoles, 8-chloro-1,2,3,4-tetrahydroquinolines, 8-chloroquinolines or quinolines.
