Stable Boron Peroxides with a Subporphyrinato Ligand

Subporphyrin B-peroxides have been synthesized in good yields by acid-catalyzed exchange reactions of subporphyrin B-methoxide with the corresponding hydroperoxides. Thermal dimerization of the subporphyrin B-hydroperoxide provided the peroxo-bridged bis(subporphyrin) quantitatively. These subporphyrin B-peroxides are fairly stable under ambient conditions, which allowed their isolation and full characterization as the first examples of structurally authenticated boron hydroperoxides, acyclic boron organylperoxides, and neutral peroxo-bridged diboron species. The subporphyrin B-peroxides thus prepared were investigated through their crystal structures, IR spectra, and cyclic voltammograms as well as by DFT calculations. The subporphyrin B-hydroperoxide oxidizes triphenylphosphine quantitatively to triphenylphosphine oxide. Acid-catalyzed exchange reactions of a subporphyrinatoboron methoxide with a range of hydroperoxides have resulted in the synthesis of a series of boron peroxides with a subporphyrinato ligand. The boron peroxides are prepared in good yields and are fairly stable under ambient conditions, thus allowing their isolation and full characterization as the first examples of structurally authenticated neutral and acyclic boron peroxides.