On the mechanism for the photooxidation of aromatic azides containing a secondary N–H bond: A sequence of intramolecular transformations with the formation of heterocyclic oximes

Ortho-Cyclization in Asymmetrically Substituted Arylnitroso Oxides

“…For example, a nitroso oxide generated by the photooxidation of β-naphthyl azide will selectively attack the α-position (Scheme ). Later, the conclusions made in the work of ref were confirmed experimentally on the example of nitroso oxides generated from 5-azido-1 H -indazole and 5-azido-2-methyl-1 H -indole: both nitroso oxides underwent ortho-cyclization exclusively at position 4 of the heteroaromatic system …”

“…Later, the conclusions made in the work of ref 4 were confirmed experimentally on the example of nitroso oxides generated from 5-azido-1Hindazole and 5-azido-2-methyl-1H-indole: both nitroso oxides underwent ortho-cyclization exclusively at position 4 of the heteroaromatic system. 11 Second, it was found that the presence of a substituent at the ortho position facilitates the ortho-cyclization. Thus, under the photooxidation of 2,4-dimethoxyphenyl azide, a nitrile oxide, which was formed as a result of the reaction of the nitroso oxide group with the substituted ortho-carbon atom, was obtained as the sole product.…”

“…Nitrile oxides of common structure 4 are stable enough, and they were isolated and identified during the photooxidation of 4-methoxyphenyl azide and 2,4-dimethoxyphenyl azide . In other cases, a number of carbocyclic and heterocyclic compounds ,− were obtained by the photooxidation of aromatic azides. Their formation was due to further intramolecular transformation of nitrile oxides with participation of the CNO group and a suitable reactive center.…”