Stable free nitroxyl radicals as oxidation catalysts and process for oxidation

摘要

The instant invention relates to stable free nitroxyl radicals of formula (I) wherein at least one of the substituents R is -O. and the others are hydrogen or OH; X is -NR₁R₂, wherein R₁ and R₂ are independently hydrogen, C₁-C₁₈alkyl or together with the nitrogen atom to which they are bound form a 5 or 6 membered ring which may be further interrupted by an O atom. Further subjects of the invention are an oxidation process for alcohols to aldehydes or ketones or to carboxylic acids in the presence of a compound of formula (I) and the use of stable free nitroxyl radicals of formula (I) as oxidation catalysts.