Oxidation of hydrocarbons by aqueous platinum salts: mechanism and selectivity

Water-soluble organic compounds are selectively oxidized by aqueous solutions of chloroplatinum(II) and chloroplatinum(IV) salts. p-Toluenesulfonic acid undergoes stepwise hydroxylation to the corresponding alcohol and aldehyde, with no further oxidation to the carboxylic acid; p-ethylbenzenesulfonic acid is functionalized at both the benzylic and methyl positions. Ethanol is converted to a spectrum of C_2 (chloro)oxygenates, including ethylene glycol and 2-chloroethanol, products resulting from methyl fundionalization. n-Propanol is also significantly attacked at the methyl position. ^(13)C labeling and kinetics studies were used to elucidate mechanistic pathways. The reactivity of a methyl group C-H bond is at least as high as that of a C-H bond CY to oxygen, in contrast to most alkane conversion systems.