Alkane oxygenation with H2O2 catalysed by FeCl3 and 2,2′-bipyridine

Iron(iii) and cobalt(iii) complexes with both tautomeric (keto and enol) forms of aroylhydrazone ligands: catalysts for the microwave assisted oxidation of alcohols

Aroylhydrazone Fe(iii) and Co(iii) complexes of both keto and enol tautomeric forms of the ligand are reported and shown to catalyze the microwave-assisted solvent-free peroxidative oxidation (by TBHP) of primary and secondary alcohols.

Molecular iron complexes as catalysts for selective C–H bond oxygenation reactions

This feature article summarises recent developments in homogeneous C–H bond oxygenation catalysed by molecular iron complexes.

Cobalt aminodiphosphine complexes as catalysts in the oxidation of n-octane

New cobalt “PNP” aminodiphosphine complexes have been prepared and characterised. They show good catalytic activity in the oxidation of n-octane to C8 oxygenates using tert-butyl hydroperoxide as an oxidant.

Cytochrome P450 catalyzed oxidative hydroxylation of achiral organic compounds with simultaneous creation of two chirality centers in a single C-H activation step

Regio- and stereoselective oxidative hydroxylation of achiral or chiral organic compounds mediated by synthetic reagents, catalysts, or enzymes generally leads to the formation of one new chiral center that appears in the respective enantiomeric or diastereomeric alcohols. By contrast, when subjecting appropriate achiral compounds to this type of C-H activation, the simultaneous creation of two chiral centers with a defined relative and absolute configuration may result, provided that control of the regio-, diastereo-, and enantioselectivity is ensured. The present study demonstrates that such control is possible by using wild type or mutant forms of the monooxygenase cytochrome P450 BM3 as catalysts in the oxidative hydroxylation of methylcyclohexane and seven other monosubstituted cyclohexane derivatives.

Development of a General and Efficient Iron-Catalyzed Epoxidation with Hydrogen Peroxide as Oxidant

The development of inexpensive and practical iron catalysts for the environmentally benign epoxidation of olefins with hydrogen peroxide as terminal oxidant is described. By systematic variation of ligands, metal sources, and reaction conditions, it was discovered that FeCl3 x 6 H2O in combination with pyridine-2,6-dicarboxylic acid and different amines shows high reactivity and excellent selectivity towards the epoxidation of aromatic olefins and moderate reactivity towards that of aliphatic olefins.

An efficient biomimetic Fe-catalyzed epoxidation of olefins using hydrogen peroxide

A new, environmentally benign and practical epoxidation method was developed using inexpensive and efficient Fe catalysts. FeCl3.6H2O in combination with commercially available pyridine-2,6-dicarboxylic acid and amines showed excellent reactivity and selectivity towards aromatic olefins and moderate reactivity towards 1,3-cyclooctadiene utilizing H2O2 as the terminal oxidant.

Ligand effects on NiII-catalysed alkane-hydroxylation with m-CPBA

Nickel(ii) complexes supported by a series of pyridylalkylamine ligands [tris(2-pyridylmethyl)amine (TPA; complexes and ), tris[2-(2-pyridyl)ethyl]amine (TEPA; complexes and ), 6-[N,N-bis(2-pyridylmethyl)aminomethyl]-2,4-di-tert-butylphenol ((Dtbp)Pym2H; complexes and ), 6-[N,N-bis[2-(2-pyridyl)ethyl]aminomethyl]-2,4-di-tert-butylphenol ((Dtbp)Pye2H; complexes and ), N-benzyl-bis(2-pyridylmethyl)amine ((Bz)Pym2; complex ) and N-benzyl-bis[2-(2-pyridyl)ethyl]amine ((Bz)Pye2; complex )] have been synthesized and structurally characterized by X-ray crystallographic analysis [coordinating counter anion (co-ligand) of complexes n (n = 1-6) is AcO(-) and that of complexes n (n = 1-4) is NO(3)(-)]. All complexes, except , were obtained as a mononuclear nickel(ii) complex exhibiting a distorted octahedral geometry, whereas complex was isolated as a dinuclear nickel(ii) complex bridged by two nitrate anions. Catalytic activity of the nickel(ii) complexes were examined in the oxidation of cyclohexane with m-CPBA as an oxidant. In all cases, the oxygenation reaction proceeded catalytically to give cyclohexanol as the major product together with cyclohexanone as the minor product. The complexes containing the pyridylmethylamine (Pym) metal-binding group (, , ) showed higher turnover number (TON) than those containing the pyridylethylamine (Pye) metal-binding group (, , ), whereas the alcohol/ketone (A/K) selectivity was much higher with the latter (Pye system) than the former (Pym system). On the other hand, the existence of the NO(3)(-) co-ligand (, and ) caused a lag phase in the early stage of the catalytic reaction. Electronic and steric effects of the supporting ligands as well as the chemical behavior of the co-ligands on the catalytic activity of the nickel(ii) complexes have been discussed on the basis of their X-ray structures.