Catalytic reactions are vital components of living systems and have played a key role in major industrial processes. From this point of view, synthesis and characterization of new families of metal complexes that may find use as efficient catalysts in oxidation processes is an essential exercise of both academic and industrial importance. A large set of iron complexes (homo- and heteronuclear carboxylates, and Schiff-type complexes) have been tested for their ability to oxygenate C-H bonds of hydrocarbons. Adamantane has been used as a model compound of aliphatic hydrocarbons containing secondary and tertiary carbon atoms in order to evaluate sec/tert selectivity. The catalytic reactions have investigated two practical oxo-donor systems: (i) the combination of dioxygen and a reducing agent (Zn dust); and (ii) hydrogen peroxide alone. The iron-based Barton’s GifIV-type systems (Fecat/Zn/O2 in pyridine/acetic or pivalic acid) have been studied in detail for the selective oxygenation of cycloalkanes, using a wide range of pre-catalysts (34 samples). The catalytic activity of the iron-containing pre-catalysts usually is quite moderate, but the oxidation of adamantane by these systems, in most cases provided complete product profiles (1-adamantanol, 2-adamantanol, 2-adamantanone, 2-(1-adamantyl)pyridine, 4(1-adamantyl)-pyridine, 2-(2-adamantyl)pyridine, and 4-(2-adamantyl)pyridine), suggesting a radical mechanism of adamantane oxidation, as previously observed in Gif chemistry. Typically, oxo- products are present in much larger amounts than pyridine-adamantyl coupling products with the current O2/Zn system, due to the obligatory presence of dioxygen. The selectivity for tert/sec functionalization varies in large limits (2-4), indicating a competing radical and non-radical pathways in which a potent oxidant is involved. The same set of pre-catalysts has been investigated in the reactions of hydrogen peroxide mediated oxidations of adamantane under inert atmosphere (Fecat/H2O2 in pyridine/acetic or pivalic acid). Nevertheless, this system does not stimulate formation of the oxidation products, as noted above with respect to oxidations GifIV-type system.