Cu(OTf)2-Catalyzed Three-Component Imino Diels-Alder Reaction Using Propenylbenzenes: Synthesis of 2,4-Diaryl Tetrahydroquinoline Derivatives

Copper(II) triflate mediated three-component [4+2]-cycloaddition reactions between anilines, benzaldehydes and trans-anethole or trans-isoeugenol are reported. A simple and efficient one-pot method for the synthesis of diverse 2,4-diaryl-1,2,3,4-tetrahydroquinolines under mild conditions in the presence of catalytic amounts (10 mol %) of Cu(OTf)2 was developed. Attempts toward an asymmetric imino Diels-Alder reaction are discussed.