The reactions of alkynes, cyclopropanes, and benzene derivatives with gold(III)

The reaction of gold(III) compounds with alkynes, arenes, and cyclopropanes have been studied. With the first two, the products can be accounted for in terms of electrophilic attack by the metal on the unsaturated centre. The reaction with alkynes bears a close resemblance to the mercury(II)-catalysed hydration but leads to higher conversions. Aromatic compounds react to give chloroarenes, the isomer distribution being consistent with initial metallation of the ring followed by replacement of the dichlorogold group by a chlorine atom. However, isolation of the intermediate arygold compounds did not prove possible. Cyclopropanes were not oxidised to the expected 1,3-adducts; instead 1,2-adducts resulting from initial gold(III)-catalysed isomerisation to an alkene were obtained.