Alternating Current Electrolysis as Efficient Tool for the Direct Electrochemical Oxidation of Hydroxamic Acids for Acyl Nitroso Diels–Alder Reactions
Jan Fährmann, Gerhard Hilt
Abstract
The acyl nitroso Diels-Alder reaction of 1,3-dienes with electrochemically oxidised hydroxamic acids is described. By using alternating current electrolysis, their typical electro-induced decomposition could be suppressed in favour of the 1,2-oxazine cycloaddition products. The reaction was optimised using Design of Experiments (DoE) and a sensitivity test was conducted. A mixture of triethylamine/hexafluoroisopropanol served as supporting electrolyte in dichloromethane, thus giving products of high purity after evaporation of the volatiles without further purification. The optimised reaction conditions were applied to various 1,3-dienes and hydroxamic acids, giving up to 96 % isolated yield.
Topics & Concepts
ChemistryNitrosoElectrolysisCycloadditionNitroso CompoundsDiels–Alder reactionTriethylamineElectrochemistryOrganic chemistryDichloromethaneDecompositionYield (engineering)CyclohexeneElectrolyteCatalysisElectrodeMaterials scienceMetallurgySolventPhysical chemistryRadical Photochemical ReactionsOxidative Organic Chemistry ReactionsChemical Synthesis and Reactions