The catalytic efficacy of Co(salen)(AL) in O2 oxidation reactions in CO2-expanded solvent media:: Axial ligand dependence and substrate selectivity

This work correlates the basicity of various axial ligands (AL), including triethylamine, methylimidazole, pyridine, acetonitrile or water, with the efficacy of catalytic oxidation of 2,6-di-tert-butylphenol by Co(salen)(AL) in CO(2)-expanded methylene chloride. Further, Co(salen)(AL)O(2) abstracts hydrogen atoms from substrates of high to intermediate reactivity (BDECH <= similar to 90 kcal/mol).