Synthesis of tetralin and chromane derivatives via In-catalyzed intramolecular hydroarylation

We report herein that In(OTf)3 is an effective catalyst for the intramolecular hydroarylation of ω-aryl-1-alkenes to form tetralin and chromane derivatives. Though narrower in substrate scope when compared to the Ru-catalyzed version, the reaction catalyzed by In(OTf)3 gave better and cleaner reactions in selected cases.