Unprecedented migration of a methyl group in 2-(2',6'-dimethylphenylazo)-4-methylphenol mediated by ruthenium.

An unprecedented chemical transformation of 2-(2',6'-dimethylphenylazo)-4-methylphenol has been observed upon its reaction with [Ru(PPh(3))(2)(CO)(2)Cl(2)] whereby the methyl group at the 2' position migrates to the 4' or 6' position.