Microwave-Assisted Domino Povarov-Type [4+2] Cycloaddition: A Rapid Access to 7-Phenyl-6 H -chromeno[4,3-b]quinolines

A convenient, facile, and eco-friendly approach to synthesizing 7-phenyl-6H-chromeno-[4,3-b]quinolines under microwave irradiation is presented. The current strategy enabled the synthesis of chromenoquinoline frameworks at 80 degrees C under shorter reaction times via intermolecular Schiff base formation followed by an intramolecular inverse demand hetero-Diels-Alder [4+2]-cycloaddition reaction by using a catalytic amount of copper triflate as the sole catalyst. Consequently, one C-N and two C-C bonds are constructed in a single pot, and a wide spread of 7-phenyl-6H-chromeno[4,3-b]quinolines have been synthesized with good functional group tolerance.