ELECTROCHEMICALLY INDUCED CHAIN-REACTIONS - THE ELECTROCHEMICAL-BEHAVIOR OF NITROSOBENZENE IN THE PRESENCE OF PROTON DONORS IN TETRAHYDROFURAN

The electrochemical reduction of nitrosobenzene in tetrahydrofuran wit h tetrabutylammonium hexafluorophosphate as the supporting electrolyte and in the presence of fluorene or indene at room temperature gives a mixture of an anil (1 or 3), a nitrone (2 or 4), and azoxybenzene and requires only a catalytic amount of electricity. Lowering the tempera ture and/or increasing the proportion of proton donor favors the forma tion of the anil at the expense of the nitrone and azoxybenzene: a 97 % yield of anil 1 was obtained from an electrolysis carried out at -30 -degrees-C using 5 equiv of fluorene. The possible steps of the chain reactions involved are discussed on the basis of electrochemical and c hemical data and digital simulation. With phenylacetylene as the proto n donor, there is no reaction between nitrosobenzene and phenylacetyle ne and azoxybenzene is the main product formed.