Further studies on the pyrolytic domino cyclization of stabilized phosphonium ylides bearing an ortho-aminophenyl group

Abstract

Four new stabilized phosphonium ylides containing a 2-(benzyl(methyl)amino)phenyl group have been prepared and characterized and are found, upon pyrolysis under gas-phase flow conditions, to lose Ph3PO and benzyl radical to afford new heterocyclic products resulting from domino cyclization of both C- and N-centred radicals. Most products arise from processes of the former type and have quinoline, phenanthridine or ring-fused phenanthridine structures, while in one case a process of the latter type leads to a benzocarbazole product. The X-ray structure of a 2-(methyl(tosyl)amino)phenyl ylide is also reported.