The reactivity of a nitrosating agent (N2O3) on oxidations of alcohols and the methyl group of acetophenone were tested, Active electrophylic surface nitrosonium ions (NO+) was detected on H2SO4/SiO2 catalysts by Raman spectroscopy, suggesting a surface ionic mechanism of oxidation in agreement with the one proposed in acid aqueous solutions. Alcohols are selectively oxidized to ketones and aldehydes in high yield, useful for synthetic applications, at 25 degrees C in 1,2-dichlorethane and using commercial sulfonated styrene divinyl benzene resins (Amberlyst 15((R))) as catalysts. In addition, nitrous acid ester has been observed as intermediates according to an ionic mechanism by surface NO+. Under the same reaction conditions, acetophenone is selectively oxidized to benzoyl cyanide in high yieldand selectivity, The comparison with oxidation carried out in aqueous solution of HNO2, where benzoyl formic acid was obtained. suggests that the differences in the final products are likely due to the specific stabilizing effect of each solvent. Moreover. the reactivity of the intermediates isolated in aqueous systems implies that alpha-nitroso-acetophenone is a probable reaction intermediate also in aprotic heterogeneous systems. (c) 2005 Elsevier B.V. All rights reserved.