Highly enantioselective epoxidation of olefins by H₂O₂ catalyzed by a non-heme Fe(ii) catalyst of a chiral tetradentate ligand

Abstract

A new chiral Fe(ii)-complex mediates the asymmetric epoxidation of prochiral olefins with good enantioselectivity.

Non‐Heme FeII Diastereomeric Complexes Bearing a Hexadentate Ligand: Unexpected Consequences for the Spin State and Catalytic Oxidation Properties

“…By using the peroxide shunt strategy, some Fe II complexes supported by polyazadentate ligands have proven capable of promoting the activation of hydrogen peroxide leading to the oxidation of olefinic or aliphatic substrates as well as the hydroxylation of aromatic C−H bonds . Catalytic activities with improved regio‐ or enantioselectivity and efficiency have also been observed with more rigid ligand backbones by replacing the ethylenediamine linker of the ligand by enantiomerically pure bipyrrolidine, bipiperidine, or cyclohexanediamine . Additionally, the presence of bulky substituents has been shown to strongly influence the site of aliphatic C−H oxidation in different substrates .…”

Chiral Iron Complexes in Asymmetric Organic Transformations

“…In 2019 complex 28 was also reported to work as catalyst for the asymmetric epoxidation of a wide scope of alkenes with good enantioselectivity, but generally with slightly lower activity than other complexes already mentioned (Figure 16). [53] …”

Exploration of highly electron-rich manganese complexes in enantioselective oxidation catalysis; a focus on enantioselective benzylic oxidation

“…When using this acid, an increase in ee values of the alcohol product has been documented for several manganesecatalyzed and iron-catalyzed oxidations. 42,43,45,57,59,92 Therefore, here we have studied the oxidation of substrate 6 using 2-eha following the previously mentioned conditions (Table 3). With 2-eha, complexes (S,S)-1 and 2 showed similar benzylic alcohol yields as with the use of acetic acid (34% yield), whereas the formation of overoxidized ketone product slightly increased to 7-8% yield.…”