Characterization of reactive intermediates generated during photolysis of 4-acetoxy-4-aryl-2,5-cyclohexadienones: oxenium ions and aryloxy radicals.

摘要: Aryloxenium ions 1 are reactive intermediates that isoelectronic with the better known arylcarbenium and arylnitrenium ions. They proposed to be involved in synthetically industrially useful oxidation reactions of phenols. However, mechanistic studies these limited. Until recently, lifetimes solution their reactivity patterns were unknown. Previously, quinol esters 2 have been used generate 1, which indirectly detected by azide ion trapping adducts 4 at expense quinols 3, during hydrolysis dark. Laser flash photolysis (LFP) 2b presence O2 aqueous leads two λmax 360 460 nm, respectively, while pure CH3CN only one species 350 nm is produced. The intermediate was previously identified as 1b based on direct observation its decomposition kinetics N3−, comparison trappi...