Silver(i)-catalyzed tandem reaction of enynones and 4-alkynyl isoxazoles: regioselective synthesis of highly functionalized 4H-furan[3,4-c]pyrroles

This work reports a silver(i)-catalyzed tandem reaction of enynones with 4-alkynyl isoxazoles. The reaction occurred via yne-enones bearing an imine group as a key intermediate. The subsequent tandem cyclization of the intermediate provided access to highly functionalized 4H-furo[3,4-c]pyrrole derivatives. No 6 pi electrocyclic reaction of the key intermediate was observed.