Gold(III) as an electrophilic oxidant of alkenes

Abstract

The products of oxidation of a variety of olefins by tetrachloroauric acid in methanol are reported. They are satisfactorily accounted for by a scheme in which gold(III) acts as an electrophile to give an organometallic adduct; this breaks down by heterolysis of the C–Au bond, accompanied by competition between rearrangement of a neighbouring substituent and uptake of a nucleophile. In all cases a close similarity was observed with the products obtained from oxidations by thallium(III) and lead(IV); where divergences occur they can be accounted for in terms of either the different ligands about the metal atom or the different leaving-group abilities of the metal substituents.