Novel routes to indoles, indolines, quinolines and tetrahydroquinolines from N-(cyclohexylidene)amines

Article abstract of DOI:10.1016/0040-4020(96)00046-4

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