Nitrenium cation

Thermal decomposition of the triazolopyridinium salt 31 in dichlorobenzene at 180 °C resulted in compounds 32 and 33 (Scheme 9), providing convincing support for the intermediate formation of a nitrenium cation <1997JOC1136>. 

Nitrenium cation is an extremely unstable species (89-91). That is why nitrenium complexes are usually prepared by the interaction of organic compounds with some sources of nitrenium cation (91, 92). Thus, the interaction of O-mesityl-sulfonylhydroxylamine with 1,10-phenanthroline results in the formation of 1 -amino- 1,10-phenanthrolinium mesitylenesulfonate (93-99). The structure of this salt has been confirmed by H and, 3C NMR spectroscopy (93,... 

Clozapine and olanzapine are atypical antipsychotic drugs used in the treatment of schizophrenia. Their strnctnres are depicted in Scheme 2.36. The use of clozapine and olanzapine, which are more effective than standard neuroleptic drugs in the treatment of refractory schizophrenia, is, however, limited becanse of their adverse effects. These adverse effects are ascribed to the formation of the corresponding cation-radicals in living organisms under oxidation by bone marrow cells. These cation-radicals eliminate protons from the NH fragments and generate their nitrenium cations. The nitreninm cations are covalently bonnd to the life-important proteins. This results in the toxic effects of clozapine and olanzapine (Sikora et al. 2007). 

Dissolving o-hydroxylaminobiphenyl in concentrated sulfuric acid gave the typical carbazole blue color basibcation produced carbazole quantitatively. More dilute sulfuric acid and hydrofluoric acid were less efficient in forming the heterocycle, presumed to be produced via a nitrenium cation. 

Aziridines. The synthesis of aziridines has been covered in several major reviews <2003CRV2905, 2004T2701, B-2006MI1 >. The intermolecular cycloaddition of an electron-deficient species such as a nitrene, a nitrenium cation, or a carbene (or their formal equivalents) to the -bond of an alkene, alkyne, imine, or nitrile is a significant approach to aziridines and azirines (Scheme 5). These reactions are often named aziridinations. 

Comparison of the products obtained by oxidation with CBT and the results of electrochemical oxidation of a mixture of 2-phenylindole with arylamines permits speculation that amination probably proceeds through formation of nitrenium cation from N-chloramine [86JCS(P1)607] (Scheme 115). 

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