Efficient Intramolecular Friedel-Crafts Cyclization of Allylic Halides

Significance

In(III) salts were found to be specific and robust catalysts for intramolecular Friedel-Crafts cyclization of allylic bromides. This is a simple method for the annelation of a six-membered ring, which may bear a heteroatom or a functional group. The conditions are remarkably mild and the substrate scope is relatively broad, including deactivated arenes. A unique catalytic activity of indium salts in this reaction may lead to the development of new useful catalytic methods with their participation.