Competitive major carbon-carbon bond activation (CCA) and minor carbon-hydrogen bond activation (CHA) channels are identified in the reaction between rhodium (II) meso- tetramesitylporphyrin [RhII (tmp)](1) and 2, 2, 6, 6-tetramethyl-piperidine-1-oxyl (TEMPO)(2). The CCA and CHA pathways lead to formation of [RhIII (tmp) Me](3) and [RhIII (tmp) H](5), respectively. In the presence of excess TEMPO,[RhII (tmp)] is regenerated from [RhIII (tmp) ...