The metal-catalyzed oxidation of organic compounds with t-butyl hydroperoxide (TBHP) and Rh(PPh₃)₃ and Rh⁺(diphos) has been investigated. Under appropriate conditions both catalysts give identical results; anthracene is converted into anthraquinone, 1-octene into 2-octanone, and 1-phenylethanol into acetophenone, with 95 to 100% isolated yields. The phosphine ligands of the catalysts are rapidly attacked during the oxidations, but this does not decrease the activity of the catalytic system. The formation of 2-octanone from 1-octene is believed to be due to a metal-centered mechanism rather than to a free radical pathway. The same mechanism should apply to the oxidation of anthracene and 1-phenylethanol.