Native α- and β-Cyclodextrin Cobalt Complexes as Catalysts in Sulfoxidation Reaction

Four complexes were synthesised between bromide cobalt salt and native α- and β-cyclodextrins using dichloromethane or ethyl acetate as solvents. These were characterised by techniques such as IR, TGA and UV–vis diffuse reflectance. These complexes were used as catalysts in the sulfoxidation reaction, being β-CD/CoBr_2(DCM) is the more efficient complex. The reaction conditions studied yielded good results with high chemoselectivity, as the aldehyde and sulfoxide functional groups were not oxidized under these conditions. The evaluation using green chemistry parameters showed good results. The use of EtOAc, a green solvent, in the synthesis of the complexes is highlighted.