Sc(OTf)3-catalyzed synthesis of indoles and SnCl4-mediated regioselective hydrochlorination of 5-(arylamino)pent-3-yn-2-ones.

Highly substituted indole derivatives bearing alkyl and aryl moieties can be prepared by Sc(OTf)(3)-catalyzed Friedel-Crafts alkenylation of 5-(arylamino)pent-3-yn-2-ones. In addition, a method for regioselective hydrochlorination of 5-(arylamino)pent-3-yn-2-ones mediated by SnCl(4) in moderate to good yields (up to 84%) has been developed. The resulting exclusive Z-selectivity of the C-Cl bond can be further exploited using cross C-N coupling reactions.