Synthetic and mechanistic studies of some nitrene insertion reactions

Abstract

A short review of aromatic nitrene chemistry is presented in the Introduction, with particular emphasis with recent developments reported in the literature.
Part I of the discussion describes the thermolytic and photolytic decomposition of 2-azidotriphenylmethane in the presence of singlet and triplet sensitizing and quenching reagents. A hypothesis which attempts to relate the observed products to the spin state of the nitrene is discussed.
In Part II of the discussion, the preparation and thermolytic decomposition of 2-azido-4',4”-dimethoxytriphenyl- methane is described. Amongst other products, a novel bicyclic pyrido-indole derivative was isolated and a discussion on the mechanism of its formation is included.
In Part III is described the investigation into aromatic nitrene insertions in heterocyclic systems analogous to the di- and triphenylmethanes. Thus the attempted preparation of 2—(2— azidobenzyl)furan, and the successful preparation of c{, oC -di-(2- furyl)-2-nitrotoluene and its analogues are described. Deoxygenation of the methyl substituted analogue yielded a novel furyl carbazole ring system. The spectral characteristics of this compound and its attempted synthesis are discussed.
Full experimental details for Parts I, II and III are included in the last section of this thesis.