One electron oxidations of benzyl and 2-phenylethyl phenyl ethers. The fate of the intermediate radical cations

A study of the oxidation of ethers with the enzyme laccase under mediation by two N–OH–type compounds

“…10%, by GC-MS), which is a typical outcome of radical cations of ethers. 26,27 The difference with the efficient oxidation of isochroman to 3,4-dihydroxycoumarin under mild condition, with the laccase-HBT and laccase-HPI systems, is striking and confirms the operation of a different, radical in nature, mechanism of oxidation by the Med-O species, at least with substrates endowed with a redox potential equal or higher than 1.4-1.5 V/NHE. Further along this line, the anodic oxidation of trans-stilbene oxide to the radical cation intermediate has been found to give rise to benzophenone and diphenylacetic acid; 26 neither of these two products was found in our case, because transstilbene oxide was recovered unreacted from incubation with laccase-HBT.…”

“…On the other hand, further oxidation of the hemiacetal by Med-O yields the other observed product, that is the ester. 26,27 The second route occurs almost exclusively with the two cyclic precursors (runs 5 and 6), most likely due to the higher stability of the cyclic (sugar-analogue) hemiacetal intermediate, to afford the corresponding lactones in synthetically interesting yields. In contrast, oxidation to the ester-level was only a minor path in the laccase-TEMPO case.…”

Suzuki–Miyaura Cross-Coupling of Potassium Alkoxyethyltrifluoroborates: Access to Aryl/Heteroarylethyloxy Motifs

“…1-Methoxy-4-(2-phenoxyethyl)benzene 4d: 27 obtained as a colorless oil (18.0 mg, 31%). 1 H NMR (CDCl 3 , 500 MHz): δ 7.31–7.28 ( m , 2H), 7.23 ( d , J = 8.5 Hz, 2H), 6.96 ( t , J = 7.5 Hz, 1H), 6.93 ( d , J = 8.0 Hz, 2H), 6.88 ( d , J = 8.5 Hz, 2H), 4.16 ( t , J = 7.0 Hz, 2H), 3.82 ( s , 3H), 3.06 ( t , J = 7.0 Hz, 2H).…”

Monoterpenoids

“…160 Oxidation of p-cymene with ceric ammonium nitrate in acetic acid leads to mixtures of ( 144) and (145). 161 The latter compounds are probably formed via an intermediate a-methylstyrene.…”