Preparation, structure, and unexpected chemistry of phosphoranyl-derived benziodoxoles

Novel phosphoranyl-derived benziodoxoles were prepared by the reaction of 1-acetoxybenziodoxole with stabilized phosphonium ylides [1-triphenylphosphoranylidene-2-propanone and (carbomethoxymethyl)triphenylphosphoranylidene acetate]. X-ray crystallographic analysis of these compounds demonstrates the significance of secondary bonding interactions, which link individual molecules into infinite chains. An unusual ligand exchange on an iodine(III) center resulting in the substitution of a carbon ligand with an oxygen ligand was observed in the reaction of these compounds with strong acids.