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A highly stable and easy to synthesize aluminium complex bearing a flexible N2O2-donor salabza ligand (N,N'-bis(salicylene)-2-aminobenzylamine) in combination with tetrabutylammonium bromide forms an active binary catalytic system for the cycloaddition of CO2 to epoxides (TOFs 120-3434 h(-1)) under mild conditions (10 bar, 80 °C) and low catalyst loadings (0.05-0.2 mol%). Kinetic experiments have shown that the cycloaddition of CO2 to styrene oxide catalyzed by 1/TBAB is first order in 1, TBAB, CO2 and epoxide. A reaction mechanism is proposed based on these observations. Fe(iii) and Co(iii) related complexes are less active catalysts for this reaction.

Fe(III) complexes with tridentate pyridine-imine-phenolato ligands differing in the chain length between the imine and pyridine groups (2-methylpyridine L1 and 2-ethylpyridine L2) have been synthesized. New complex [Fe(L2) 2 ]ClO 4 (2) was characterized by X-ray diffraction and spectroscopic techniques.[Fe(L1) 2 ]ClO 4 (1) and 2 form active catalysts for the cycloaddition of CO 2 to epoxides and for the epoxidation of alkenes. Catalytic systems with the more flexible skeleton (2) in combination with tetrabutylammonium bromide (TBAB) were more active than 1/TBAB in the cycloaddition of CO 2 to epoxides. TOFs up to 900 h À1 for the selective synthesis of styrene carbonate and 3640 h À1 for the synthesis of glycidol carbonate were obtained using 2/TBAB at low catalyst loadings (0.025 mol %). Additionally, 2 was also active in the epoxidation of styrene derivatives such as trans-stilbene (conversion 88 %) and trans-bmethylstyrene (conversion 100 %) using tert-butylhydroperoxide as oxidant at 60 8C in acetonitrile. Epoxidation of styrene and cyclohexene proceed at low conversions.[a] Dr.

A new tridentate pyridine‐imine‐phenolato ligand and its Fe(III) complex is prepared, characterized and its catalytic activity is tested by measuring TOFs.