An efficient procedure for the synthesis of benzoxazoles by the heteroannulation of nitriles and o-aminophenols in the presence of a catalytic amount of copper(II) trifluoromethanesulfonate, has been developed. This method represents a practical and attractive alternative for the synthesis of both 2-arylbenzoxazoles and 2-alkylbenzoxazoles.
A green and efficient strategy for the synthesis of benzoxazoles, benzothiazoles and benzimidazoles has been developed by using inexpensive, readily available, dioxygen-stable and recyclable CuFe2O4as the nanocatalyst.