ELECTROCATALYTIC OXIDATIVE COUPLING REACTION OF NAPHTHOLS AND NAPHTHOL ETHERS ON A TEMPO MODIFIED GRAPHITE FELT ELECTRODE

2-Naphthol and 2-methoxynaphthalene were quantitatively oxidized to the corresponding 1, 1'-binaphthyls in more than 90% current efficiency on a graphite felt electrode coated with a thin poly(acrylic acid) layer immobilizing 4-amino-2,2,6,6-tetramethyl-piperidinyl-1-oxyl (4-amino-TEMPO). 1-Naphthol and 1-methoxynaphthalene were also completely converted to the predicted 1,1'-, 1,2'-, and 2,2'- positioned coupling products. The reaction proceeds via electrocatalytic oxidation of the modified-TEMPO species. The electrode was not inactivated during electrolysis and could be used repeatedly.