γCDCoBr2 complexes as catalysts in sulfide oxidation and its reused

Abstract

γCDCoBr2 complexes synthesized in ethyl acetate or dichloromethane solvents or CoBr2 were used as catalysts in sulfoxidation reactions giving very good yields and high chemoselectivity. Sulfoxidation takes place in the presence of other functional groups such as –COOH, –NO2 or –CHO. A structure-reactivity analysis was carried out, correlating the Hammet σ parameters and the TOF values obtained in the oxidation reaction of the para-substituted arylmethylsulfides in the presence of each catalyst. Additionally, the effect of groups of different sizes attached to sulfur atom was analysed. Also, these reactions were evaluated using green chemistry metrics, good results were obtained in many cases. The solid complexes can be used several times, after three cycles the yield decreased only 7% (from 95 to 88%). Techniques as FT-IR and TGA were used to characterize used complexes after 1st and 6th cycles.