Radical cations: reactions of 2-phenylindole with aromatic amines under anodic oxidation. beta-Scission of an amino alkoxy radical

2-Phenyl-1H-indole reacts with p-anisidine, 2-nitro-p-anisidine and 2-nitro -p-methylaniline, under anodic oxidation, to give several products, dependi ng on the potential used and on the presence or the absence of oxygen and a deprotonating agent. This investigation gives new insights into the reacti vity of radical cations generated by a controlled anodic potential and neut ral radicals corresponding to either 2-phenyl-1H-indole or to the three ami nes studied. The chosen amines show oxidation potentials lower (p-anisidine ), equal (2-nitro-p-anisidine) or higher (2- nitro-p-methylaniline) than th at of 2-phenyl-1H-indole and the reactions were carried out at the potentia l of the studied compounds. The oxidation of 2-phenyl-1H-indole in oxygen a ffords a new indole derivative, whose formation has been explained by beta- scission of an indol-2-yloxyl radical and its structure was confirmed by X- ray analysis.