IBX Oxidation of Benzenedimethanols in the Presence of Cucurbit[8]uril

The cucurbit[8]uril (Q[8]) mediated oxidation of benzenedimethanols with o-iodoxybenzoic acid (IBX) inaqueous solution has been investigated, and the results reveal the supramolecular catalysis depends on the electronicand geometric structure of substrate. In the cases of o-benzenedimethanol (1a) and m-benzenedimethanol (1b), theIBX oxidation could be obviously enhanced by the addition of Q[8] at different extent. There is no observation ofthe catalytic activity of Q[8] when p-benzenedimethanol (1c) is subjected to the IBX oxidation. The additionamount of Q[8] is discussed herein, and the addition of more than 10% mol catalyst cannot improve the oxidationmuch more. The investigation of host-guest interactions by isothermal titration calorimetry implies the supramolecularcatalysis is related to the formation of complexes between benzenedimethanols and cucurbit[8]uril.