Iron-Mediated Carboarylation/Cyclization of Propargylanilines with Acetals: A Concise Route to Indeno[2,1-c]quinolines

FeCl3- and FeBr3-mediated tandem carboarylation/cyclization of propargylanilines with diethyl benzaldehyde acetals furnished the tetracyclic core of indeno[2,1-c]quinolines. 5-Tosyl-6,7-dihydro-5H-indeno[2,1-c]quinoline and 7H-indeno[2,1-c]quinoline derivatives were obtained in good to excellent yields, respectively, by tuning the FeX3 loadings and/or reaction temperatures.