Intermolecular Friedel–Crafts reaction catalyzed by InCl3

Our recent discovery that In(III) salts were able to activate halides catalytically under mild conditions for the intermolecular Friedel–Crafts cyclization prompted us to explore this highly efficient activation in intermolecular Friedel–Crafts reactions. The alkylation of p-xylene with allylic and benzylic halides was demonstrated under catalytic and mild condition to afford in some cases quantitative yields of the monoalkylated products without the need to employ large excesses of reactants.