We report the elusive X-ray structure of the Dess-Martin periodinane (DMP), a hypervalent iodine reagent popular amongst synthetic chemists. In the solid state, the highly crystalline compound forms an intricate coordination polymer held together by intermolecular halogen and hydrogen bonds.
The so-called Dess–Martin periodinane (DMP, 1,1,1-triacetoxy- 1,1-dihydro-1,2-benziodoxol-3(1H)-one) has emerged as one of the most useful reagents for the oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones. Its solubility in organic solvents, high reactivity under mild conditions, and lack of toxic or unpleasant byproducts renders it often preferable over other oxidation reagents and has ensured its continued popularity among synthetic chemists. DMP is usually prepared from 2-iodobenzoic acid (2) in a two-step procedure, which involves oxidation with Oxone (a formulation of peroxomonosulfate), followed by heating of the intermediary iodine(V) species IBX with acetic anhydride and catalytic amounts of p-toluenesulfonic acid. Upon repeating this procedure with an older and less-active batch of Oxone, we obtained well-defined single crystals of acetoxy-1,2-benziodoxolin-3-one as a byproduct. We quickly established that the crystal structure of this partially oxidized compound had already been described by Gougoutas and Clardy four decades ago and that the X-ray structure of IBX was also known . Browsing the Cambridge Crystallographic Data Centre, however, we were surprised to find that no X-ray structure of DMP itself has been published to date. We thus set out to investigate a range of crystallization conditions to obtain the first X-ray crystal structure of DMP. This could serve as a basis for computational investigations concerning the mechanism of the Dess–Martin oxidation.
The article is published online in Beilstein Journal of Organic Chemistry and is free to access.