214675-45-3Relevant academic research and scientific papers
Enol radical cations in solution. 13. First example of a radical dication rearrangement. One-electron oxidation of dihydrobenzofuranyl cations leads to drastic rate enhancement in the oxidative benzofuran formation from enols
Schmittel, Michael,Langels, Anja
, p. 7328 - 7337 (1998)
The synthesis and electrochemical investigation of six stable, simple enols El-EG are reported that are characterized by electron-releasing substituents in the a-position. Oxidative benzofuran formation from these enols is unusually slow because a key intermediate in the reaction, the dihydrobenzofuranyl cation X+, is substantially stabilized vs rearrangement by the attached electronreleasing substituents. The persistent cations X+ were characterized by 1H NMR and cyclic voltammetry, and the kinetics of their rearrangement was followed by UV/vis. Notably, upon oneelectron oxidation of X+ to the radical dication, the formation of the benzofurans B was markedly accelerated by a factor of > 106.
