Studies on the Chemistry of Manganese Tricarbonyl Cations of Phenol and Cresols

Treatment of (arene)tricarbonylmanganese cations (arene = phenol, cresol) with nucleophiles affords η5-cyclohexadienyl complexes that can be demetalated to give ortho-substituted phenols. Acylation of the phenolic oxygen in the η5-cyclohexadienyl complexes obtained from phenol, followed by treatment with acid, gives manganese tricarbonyl cations with coordinated monosubstituted arenes. Reaction of η5-cyclohexadienyl complexes derived from ortho- and para-cresol with acid gives meta-substituted toluene manganese tricarbonyl cations, and those derived from meta-cresol give ortho- and/or para-substituted toluene manganese complexes depending upon the nucleophiles.