Synthesis of 4‐Substituted‐1,2‐Dihydroquinolines by Means of Gold‐Catalyzed Intramolecular Hydroarylation Reaction of N‐Ethoxycarbonyl‐N‐Propargylanilines

An alternative Au(I)‐catalyzed synthetic route to functionalized 1,2‐dihydroquinolines is reported. This novel approach is based on the use of N‐ethoxycarbonyl protected‐Npropargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6‐endo cyclization product in good to high yields. In the presence of N‐ethoxycarbonyl‐N‐propargyl‐metasubstituted anilines, the regiodivergent cyclization at the ortho‐/para‐position is achieved by the means of catalyst fine tuning.