Homogeneous and supported copper(II) acetate as catalyst for C-O coupling reactions

The reactivity of copper(II) acetate as catalyst in a standard C-O coupling reaction has been systematically evaluated. Optimization of the reaction conditions resulted in a protocol involving stoichiometric amounts of reagents, a substoichiometric amount of base and 20 mol% catalyst, at 50 degrees C in 1,2-dichloroethane and under 1 atm O-2. Next, the reactivity of polymer-supported copper(II) acetate was evaluated. Although it is found that, in contrast to previous results obtained in related C-N coupling reactions, the polymer-supported catalyst is in this case less efficient than the corresponding homogeneous one, the catalyst turns out to be conveniently recovered from the reaction mixture by simple filtration.