Study of Cyclohexane and Methylcyclohexane Functionalization Promoted by Manganese(III) Compounds

Alkane functionalization using safe and low-energy processes is of great interest to industry academia. Aiming contribute the process saturated hydrocarbon functionalization, we have studied a set three manganese(III) complexes as catalysts for promoting oxidation hydrocarbons (cyclohexane methylcyclohexane) in presence hydrogen peroxide or trichloroisocyanuric acid (TCCA). The mononuclear compounds were prepared ligands H2LMet4 (6,6’-((1,4-diazepane-1,4-diyl)bis(methylene))bis(2,4-dimethylphenol), H2salen (2,2’-((1E,1’E)-(ethane-1,2-diylbis(azaneylylidene))bis(methaneylylidene))diphenol) H2salan (2,2’-((ethane-1,2-diylbis(azanediyl))bis(methylene))diphenol). catalytic carried out acetonitrile at 25 50 °C 24 h. increase temperature was important get better conversion. did not promote cyclohexane H2O2. However, they active TCCA, employing ratio 1000:333:1 equivalents substrate:TCCA:catalyst. best activity shown by compound [Mn(salen)Cl], reaching conversions 14.5 ± 0.3% (25 °C) 26.3 1.1% (50 (yield chlorocyclohexane) up 12.1 0.5% 29.8 2.2% (total yield mixture products 1-chloro-4-methylcyclohexane, 3-methylcyclohexene 1-methylcyclohexene). interaction with TCCA electron paramagnetic resonance (EPR), suggesting that [Mn(LMet4)Cl] [Mn(salan)Cl] act via different mechanism from observed [Mn(salen)Cl].