Electrocyclic ring closure of 1-azatrienes as a route to the indolo [3,2,1-ij] [1,6] naphthyridine ring system

t-Methods of annelation of indole across the 1- and 2-positions have been explored using both the intramolecular Heck reaction and Dieck- mann cyclisation. Two examples (5) and (7) of the title ring system have been produced by the thermal cyclisation of indole-3-carboxal- dehyde oximes with an alkenyl substituent at C-2