MECHANISTIC STUDIES OF THE PALLADIUM(II)-COPPER(II)-MEDIATED DEMERCURIATION OF CYCLOALKYL AND CYCLOALKYLMETHYL SYSTEMS

The likely events involved in the conversion of cyclohexylmethylmercur ic chloride into predominantly trans-4-methylcyclohexyl chloride, on t reatment with PdCl2-CuCl2, in acetic acid, have been identified by pro duct and deuterium-labelling studies. as well as by the behaviour of p robable intermediates. Extension to related cycloalkyl- and cycloalkyl methyl-mercuric chlorides is reported, and mechanistic changes occur a s a function of ring size, with elimination-re-addition of [HPdX] bein g important in cyclohexyl systems, but carbocation formation dominatin g in cyclooctyl cases.