Reactions of tetraphenyldiphosphine with carbon radicals

Abstract

1-Cyano-1-methylethyl and 1-methoxycarbonyl-1-methylethyl radicals reacted with tetraphenyldiphosphine to afford, after sulphurization, 1-cyano-1-methylethyl-(1) and 1-methoxycarbonyl-1-methylethyl-(diphenyl)phosphine sulphides (2), respectively. A mechanism involving metathesis of the P–P bond is suggested. The photosensitized reaction of 1,1-diphenylethylene gave 2,2-diphenylethenyl(diphenyl)phosphine sulphide after sulphurization. We suggest that the triplet state of the ethylene behaves like a carbon radical in its attack on the phosphorus–phosphorus bond.