On the radical chain mechanism of oxidation of a series of ferrocene derivatives with molecular oxygen

Oxygen reduction by decamethylferrocene at liquid/liquid interfaces catalyzed by dodecylaniline

“…O 2 reduction by ferrocene derivatives in organic media in the presence of an acid, such as carboxylic acids (trichloroacetic and trifluoroacetic acids) [29,30] and perchloric acid [27,31,32], has been studied for many years, although the reaction mechanism is yet unresolved. For example, the initial reaction step has been assigned to be the protonation on the Cp ring favoring the complexation of iron with O 2 [26,29,[33][34][35] or that on the iron by the formation of Fe-H intermediate [34]. Preliminary density function theoretical computations support the hypothesis that triplet molecular oxygen O 2 approaches Fe-H directly via a delocalized triplet (diradical) transition state [DMFcÁ Á ÁHÁ Á ÁOOÁ] + to yield a hydrogen peroxyl radical and H 2 O 2 finally, which will be reported soon elsewhere.…”

Polonovski-Type N-Demethylation of N-Methyl Alkaloids Using Substituted Ferrocene Redox Catalysts

“…Indeed, a range of acids such as benzoic acids has been reported to catalyze the oxidation of certain ferrocenes with molecular oxygen. 24,29 In summary, we have found that the ferrocene-mediated N-demethylation of the N-methylamines, dextromethorphan, codeine, thebaine, oripavine, and thevinone under Polonovski-type conditions is sensitive to the electronic effects of the substituent(s) on ferrocene. The reactivity of ferrocene and its methyl derivatives (Me 2 Fc, Me 10 Fc) was observed to increase in the order Me 10 Fc > Me 2 Fc > Fc, which reflects the relative electron-donor capability of these ferrocenes.…”

“…The latter result is perhaps not surprising given the requirement for the initial protonation of the substrate N-oxide (Scheme 2) and that oxidation of ferrocene itself with molecular oxygen only occurs in the presence of strong Brønsted acids. 21,28,29 Finally, to demonstrate the feasibility of reducing the current two-step protocol to one pot, a number of experiments were conducted using FcCH 2 CO 2 H on thebaine (6a) and oripavine (7a). Results are summarized in Table 3.…”

Development of a DNA-damaging ferrocene amino acid

“…Furthermore, the reaction proceeds readily at room temperature with the evolution of CO 2 , presumably from decarboxylation of a COO_ radical [4]. A radical chain mechanism is implicated, with iron oxides and side chain oxidized ferrocenes (e.g.…”