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Epoxidized vegetable oils (EVOs) are versatile building blocks for lubricants, plasticizers, polyvinyl chloride (PVC) stabilizers, and surface coating formulations. In this paper, a catalytic protocol for the efficient epoxidation of vegetable oils is presented that is based on a combination of a manganese catalyst, H 2 O 2 as an oxidant, and acetic acid as an additive. This protocol relies on the use of a homogeneous catalyst based on the non-noble metal manganese in combination with a racemic mixture of the N,N′-bis(2-picolyl)-2,2′-bispyrrolidine ligand (rac-BPBP). The optimized reaction conditions entail only 0.03 mol% of the manganese catalyst with respect to the number of double bonds (ca. 0.1 wt% with respect to the oil) and ambient temperature. This epoxidation protocol is highly efficient, since it allows most of the investigated vegetable oils, including cheap waste cooking oil, to be fully epoxidized to EVOs in more than 90% yield with excellent epoxide selectivities (>90%) within 2 h of reaction time. In addition, the protocol takes place in a biphasic reaction medium constituted by the vegetable oil itself and an aqueous acetic acid phase, from which the epoxidized product can be easily separated via simple extraction. In terms of efficiency and reaction conditions, the current epoxidation protocol outperforms previously reported catalytic protocols for plant oil epoxidation, representing a promising alternative method for EVO production.

Iron complexes derived from a bis-isoindoline-bis-pyridine ligand platform based on the BPBP ligand (BPBP = N,N′-bis(2-picolyl)-2,2′-bis-pyrrolidine) have been synthesized and applied in selective aliphatic C–H oxidation with hydrogen peroxide under mild conditions. The introduction of benzene moieties on the bis-pyrrolidine backbone leads to an increased preference of tertiary over secondary C–H bond oxidation (3°/2° ratio up to 33). On the other hand, substituting the meta-position of the pyridines with bulky silyl groups affords enhanced secondary C–H oxidation selectivity and generally leads to higher product yields and mass balances.

A method for the regioselective transformation of dienes to carbonyl compounds has been developed. Electron-rich olefins react selectively to yield valuable aldehydes and ketones. The method is based on the catalyst [Fe(OTf)2(mix-BPBP)] with an oxidant combination of H2O2 (1.0 equiv.) and NaIO4 (1.5 equiv.); it uses mild conditions and short reaction times, and it outperforms other olefin cleavage methodologies. The combination of an Fe-based catalyst, [Fe(OTf)2(mix-BPBP)], and the oxidants H2O2 and NaIO4 can discriminate between electronically different double bonds and oxidatively cleave the electron-rich bond in dienes to yield aldehydes and ketones in a regioselective manner. The reaction requires mild conditions (0-50 C) and short reaction times (70 min).

C–H and C=C bond oxidations constitute essential transformations in organic synthesis and in many biological and industrial processes. In the past decades numerous non-heme iron enzymes have been discovered and identified, that are able to conduct biological C–H and C=C bond oxidations via O2 activation in a very selective manner. Inspired by these enzymes, many efforts have been spent on modelling catalytic iron sites and active intermediates involved in catalysis, in order to achieve these oxidation reactions by molecular catalysts outside the enzyme environment. Depending on the ligand, the coordination chemistry and reactivity of synthetic non-heme iron complexes may be drastically different; accordingly, the development of ligands is of pivotal importance to the field. So far, iron complexes with tetradentate nitrogen (N4, generally aminopyridine) ligands have shown to be most successful in achieving highly regio- and stereoselective oxidation reactions utilizing H2O2 as the oxidant. Amongst them, iron complexes with a cis-α topology derived from linear bis-alkylamine-bispyridine (N2Py2) ligands have been proven to be most effective so far. This thesis describes several ligand modifications of the N2Py2 ligand platform, with the aim of either improving C–H oxidation selectivities or enhancing the lifetimes of Fe(N2Py2) complexes in oxidation catalysis. Furthermore, the practical use of the Fe(N2Py2) and Mn(N2Py2) complexes in the oxidation of a number of biologically or industrially relevant compounds, like steroidal derivatives, unsaturated fatty acids and their esters, and vegetable oils, is also investigated in this thesis.