Synthesis and Conformation Analysis of New Perphosphorylated Calix[4]resorcinarenes

The octaphosphorylation of calix[4]resorcinarenes 1 by 2-dialkylamino-1,3,2-diheterophosphorinanes 2 is described, and the effect of different factors on the structures of the resulting perphosphorylated products 3−5 was studied. Conformation analysis of these compounds by correlated 2D NMR spectroscopy and X-ray diffraction analysis was performed, and it was found that compounds 3−5, like the initial resorcinarenes 1, each have the all-cis configuration of the R groups in the methylidene bridges of the calixarene system, but different orientations of benzene rings and phosphorinane fragments with respect to one another and to the macrocycle plane. Perphosphorylated resorcinarenes 3a−c, 4a and 5a with R = alkyl exist in flattened cone conformations with the phosphorinane fragments on the same side of the macrocycle plane. The conformations of the perphosphorylated resorcinarenes 3d, 4b and 5b with R = Ph change to forms intermediate between flattened cone and 1,3-alternate. The phosphorus fragments in these compounds are located on opposite sides of the macrocycle plane. It was shown that the oxidation and sulfurisation of phosphocalixarenes 3 proceed without any change in the spatial organisation of the macrocyclic system. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)