CAN-catalyzed three-component reaction between anilines and alkyl vinyl ethers: stereoselective synthesis of 2-methyl-1,2,3,4-tetrahydroquinolines and studies on their aromatization

The CAN-catalyzed reaction between anilines and vinyl ethers at room temperature provides a convenient and efficient access to 4-alkoxy-2-methyl-1,2,3,4-tetrahydroquinolines. This reaction is stereoselective, favouring a cis arrangement for the alkoxy and methyl groups, and involves a three-component process that leaves a molecule of alcohol as the only side product. 2-Methylquinoline derivatives were efficiently prepared from 4-alkoxy-2-methyl-1,2,3,4-tetrahydroquinolines by Pd–C-promoted dehydrogenation.