The kinetic and mechanism of the reaction between phenylisocyanate and ethanol, in the presence of various additives, able to inhibit or to activate the urethane formation, have been evaluated. An alternative reaction mechanism, as a special case of second-order reaction for the reactions performed in unpolar media is proposed. In the first step of the reaction, the isocyanate group is activated through a rapid and reversible process by the "mobile"

Sodium periodate/wet silica gel in the presence of dichloromethane is an efficient reagent at room temperature for the phthalimide N-oxyl (PINO) radical generation from its precursor N-hydroxyphthalimide (NHPI). PINO reactions with cycloalkenes occur exclusively by a pure radical mechanism, contrasting with PINO's behavior when it is generated using lead tetraacetate.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

The two vinylic hydrogen atoms of cyclohexene, cyclooctene and trans-3-hexene were replaced by deuterium and the resulting dideuterio-alkenes were reacted with three >NO• radicals: 4-hydroxyTempo, di-tert-butyliminoxyl, both used as the actual radicals, and phthalimide-N-oxyl (PINO) generated from N-hydroxyphthalimide (NHPI) by its reaction with tert-alkoxyl radicals (t-RO•) and with lead tetraacetate. In all cases, except the NHPI / Pb(OAc)4

An unambiguous method for distinguishing between abstraction-addition and addition-abstraction mechanisms (and mixtures thereof) in the reaction of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl with a specifically deuterated cyclohexene, 1,2-dideuterocyclohexene, is demonstrated