Homogeneous platinum(II)-catalysed hydrogen-deuterium exchange at a saturated carbon atom

Alkenes of the type RC(CH3)2CHCH2(R = Et, Pr, or Bu) undergo hydrogen–deuterium exchange with a deuterium oxide–acetic [2H1]acid solvent containing perchloric acid in the presence of a homogeneous platinum(II) catalyst. Incorporation of deuterium into the alkyl part of the alkene occurs exclusively at C-5. It is suggested that exchange occurs via a dimeric platinum(II) species. Exchange of the olefinic protons is also found; evidence suggests that this latter exchange is essentially an acid-catalysed reaction. Dimeric complexes of the type [Pt2Cl4{RC-(CH3)2CHCH2}2] have been isolated from the reaction medium.