Intramolecular nitrene insertions into aromatic rings

Abstract

The synthesis and thermal decomposition of 2'-azido- phenyl-(3-pyridyl)methane is described in Chapter One. Pertinent reviews of arylnitrene chemistry and the reactions of nitrenes with pyridine compounds are presented in the introduction.
Decomposition of 2'-azidophenyl-(3-pyridyl)methane and the isomeric 4-pyridyl compound led, in both cases, to polymeric products. A low yield of 9H-pyrrolo[l,2-a]indole was isolated in the thermal decomposition of the 3-pyridyl compound. The synthesis and decomposition of 3-(2-azidobenzyl)pyridine-1-oxide is also discussed and similarly led to extensive polymer formation.
A review of the known chemistry of the 1,3-diazepine ring system and its benzo-fused analogues is given in Chapter Two, Initial attempts to devise synthetic routes to these compounds are also discussed.
Chapter Three describes the synthesis of 2'-nitrophenyl- di-(4-t-butylthien-2-yl)methane and its deoxygenation by triethyl- phosphite. Two products were characterised from the reaction mixture, 9-(4-t-buty1thien-2-y1)-3-¿-butylthieno[3,2-b]quinoline and 2-t>-butyl-9-(4-t-butylthien-2-yl)-3H-pyrrolo£l,2-a]indol-3- thione. The latter compound is the first example of this type of structure in such nitrene insertion reactions.
The successful synthesis and thermal decomposition of di- and tri-phenylmethane compounds bearing electron-withdrawing groups is described in Chapter Four. Products were isolated where the benzene ring had been expanded to form 10H-azepino [1,2-a]indoles.