The use of methane, the lightest hydrocarbon and primary component of natural gas, as a source for fine chemicals production remains an appealing goal on scientific, economic and environmental grounds (1-4). Transition metal catalyzed C-H bond activation is a promising approach to achieve functionalization of the strong and relatively inert C-H bonds of alkanes more generally. In one possible scenario, these reactions proceed by metal-promoted C-H bond oxidative cleavage followed by insertion of a suitable X group into the M-C bond and release of the functionalized product by means of reductive elimination of the C-X-H unit (5). Individual reaction steps for this and related catalytic cycles have been widely reported (6), but a major challenge has been that removal of the functionalized fragments from the metal coordination sphere is often unfavorable, due to the robustness of the M-C bonds. Only FINAL VERSION ACCEPTED