Synthesis of 3‐Organoseleno‐Substituted Quinolines through Cyclization of 2‐­Amino­phenylprop‐1‐yn‐3‐ols Promoted by Iron(III) Chloride with Diorganyl Diselenides

Abstract

AbstractWe have described the application of iron(III) chloride and diorganyl diselenides as cooperative partners in the cyclization of (2‐aminoaryl)‐2‐ynols for the regioselective synthesis of 3‐organoseleno quinolines. The optimized reaction conditions were applied to (2‐aminoaryl)‐2‐ynols that contain a wide range of functional groups, including electron‐rich and electron‐poor substituents. The reaction showed regioselectivity for six‐membered quinoline products, which were formed by a 6‐endo‐dig ring closure, instead of a 5‐exo‐dig process for the formation of indole products. In addition, we also found that (2‐aminoaryl)‐2‐ynols and a catalytic amount of iron(III) chloride, in the absence of diorganyl diselenides, afforded the corresponding quinoline derivatives without the organoseleno moiety at the 3‐position.