Schiff base ligands are considered “privileged ligands” because they are easily prepared by the condensation between aldehydes and imines. Stereogenic centres or other elements of chirality (planes, axes) can be introduced in the synthetic design. Schiff base ligands are able to coordinate many different metals, and to stabilize them in various oxidation states, enabling the use of Schiff base metal complexes for a large variety of useful catalytic transformations. Practical guidelines for the preparation and use of different Schiff base metal complexes in the field of catalytic transformations are discussed in this tutorial review.

Metal–Salen Schiff base complexes in catalysis: practical aspects

Catalytic asymmetric oxidations using optically active (salen)manganese(III) complexes as catalysts

The first salen ligand and Cu complex were discovered in 1889, and gradually the potential catalytic activity of subsequent salen species has been recognised, particularly in the case of achiral salen complexes in oxidation reactions. The development of chiral salen metal complexes and catalysts in the last decade has however stimulated a very rapid growth in the chemistry and application of these species. The variety of asymmetric reactions in which particular chiral metal salen complexes are proving useful grows steadily, and there is no evidence of this growth slowing. This review summarises the key work and references on soluble chiral metal salen complex catalysts categorised according to the metal centre. It also describes the work to date on producing supported heterogeneous chiral analogues of some of these.

Utilisation of homogeneous and supported chiral metal(salen) complexes in asymmetric catalysis

Chromium− and Manganese−salen Promoted Epoxidation of Alkenes

Recent progress in regioselective and enantioselective epoxidations catalyzed by metalloporphyrins is discussed here, with an explanation of the biomimetic antecedents of this area and its relevance to synthetic applications. Classification of the catalysts that have been studied allows useful conclusions to be drawn about the development of this field. In particular, both the most promising biomimetic and practical catalysts have arisen from systems that can be systematically modified by convenient synthetic methodology.

https://science.sciencemag.org/content/sci/261/5127/1404.full.pdf

Regioselective and enantioselective epoxidation catalyzed by metalloporphyrins

Mechanism of the chromium-catalyzed epoxidation of olefins. Role of oxochromium(V) cations

La transposition moleculaire d'une serie de complexes hexene-5yl-Co(III) avec diverses bases de Schiff a lieu par un processus radicalaire en chaine inhabituel. Influence de traces d'impuretes sur la facilite de la transposition hexene-5yl→cyclopentylmethyl

E. G. Samsel

Papers

Mechanism of the chromium-catalyzed epoxidation of olefins. Role of oxochromium(V) cations

Radical chain mechanisms for alkyl rearrangement in organocobalt complexes

Oxidative alkylation of cobalt complexes with hydrazines

Radical Chain Mechanism for Alkyl Rearrangement in Organocobalt Complexes.

Oxidative Alkylation of Cobalt Complexes with Hydrazines.