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Aryl azides have been used as atom-efficient nitrene transfer reagents in the (porphyrin)ruthenium-catalyzed amination of olefins. Several azides, olefins and [Ru(porphyrin)CO] complexes were tested to investigate the scope and limits of the reaction. Quantitative yields and short reaction times were achieved by using terminal olefins and aryl azides bearing electron-withdrawing groups on the aryl moiety. The reactions were influenced by steric factors. Internally disubsti-

Squalene and its hydrogenated derivate squalane are widely used in the pharmaceutical and cosmetic fields. The two compounds are mainly produced from the liver oil of deep sea sharks and from olive oil distillates. Squalene and squalane from shark cost less than the same compounds derived from olive oil, and the use of these shark-derived compounds is unethical in cosmetic formulations. In this work we investigate whether (13)C/(12)C and (2)H/(1)H ratios can distinguish olive oil from shark squalene/squalane and can detect the presence of shark derivates in olive oil based products. The (13)C/(12)C ratios (expressed as delta(13)C values) of bulk samples and of pure compounds measured using isotope ratio mass spectrometry (IRMS) were significantly lower in authentic olive oil squalene/squalane (N: 13; -28.4 +/- 0.5 per thousand; -28.3 +/- 0.8 per thousand) than in shark squalene/squalane samples (N: 15; -20.5 +/- 0.7 per thousand; -20.4 +/- 0.6 per thousand). By defining delta(13)C threshold values of -27.4 per thousand and -26.6 per thousand for olive oil bulk and pure squalene/squalane, respectively, illegal addition of shark products can be identified starting from a minimum of 10%. (2)H/(1)H analysis is not useful for distinguishing the two different origins. Delta(13)C analysis is proposed as a suitable tool for detecting the authenticity of commercial olive oil squalene and squalane samples, using IRMS interfaced to an elemental analyser if the purity is higher than 80% and IRMS interfaced to a gas chromatography/combustion system for samples with lower purity, including solutions of squalane extracted from cosmetic products.

[Ru(CO)(porphyrin)] complexes have been found to catalyze the direct aziridination of conjugated dienes by aryl azides with high chemoselectivity, to provide N-aryl-2-vinylaziridines. To determine the scope of the reaction, several hydrocarbons and azides were tested. The reactions between 2,3-dimethylbuta-1,3-diene and aryl azides bearing electronwithdrawing groups in the para or meta positions in their aryl moieties occur very efficiently in short times, while the selectivities of the aziridinations are governed by the steric hindrances of the double bonds, so lower yields are regis-

Herein we report the one-pot synthesis of several N-heterocyclic compounds by rearrangement reactions of N-aryl-2-vinylaziridines. The optimization of the synthetic methodology employed allowed us to obtain differently substituted 2,5-dihydro-1H-benzo[b]azepines in good yields and purities. The relationship between the nature of the starting N-aryl-2-vinylaziridine and the obtained N-heterocycle was also investigated. Finally, to rationalize all the experimental results reported in this paper a theoretical study was performed that casts light on the reaction mechanism.