New syntheses of aziridines and azirines.

The work presented in this thesis concerns the oxidation of N-amino compounds and the interception of the reactive intermediates, the postulated amino-nitrenes. The Introduction has been divided into three parts concerning (1) the synthesis of aziridines from nitrenes and olefins (2) nitrogen inversion as studied by N.M.R. spectroscopy (3) synthetic approaches to 2H-azirines. The preparation of one new N-amino compound, N-aminophthalimidine is reported and the oxidations of that compound and of N-aminophthalimide, N-aminonaphthalimide, 3-aminobenzoxazolin-2(3H)-one and N-aminocarbazole are reported. The oxidation of the N-amino compounds alone leads to a variety of products, a major one frequently being the deaminated compound. The mechanism of oxidative deamination is discussed and an intermediate in the reaction, a tetrazane, has been isolated. Oxidations in the presence of olefins and sulphoxides generally give aziridines and sulphoximines. The N.M.R. spectra of most aziridines studied showed the presence of invertomers at room temperature. The implications of slow nitrogen inversion as a tool for conformational analysis are discussed. Several chloro- and bromo-substituted aziridines were found to undergo a facile thermal rearrangement with ring opening to give hydrazones. Sulphoximines and certain aziridines substituted in the 2-position with an unsaturated group were shown to produce the amino-nitrenes upon photolysis. When N-aminophthalimide was oxidised in the presence of acetylenes, 2H-azirines and not 1H-azirines were isolated. The mechanism of this novel rearrangement is discussed, and other attempted syntheses of the 1H-azirine system are reported.