Lewis Acid-Mediated\nRegioselective Hydrofunctionalization\nof Styrenes with Isatins and Heterocycles

The\nligand-free Lewis acid-mediated regioselective hydroamination\nand hydroarylation of styrenes have been successfully developed in\nthe presence of isatins or heterocyclic aryl compounds such as benzothiophenes\nand benzofurans. The reactions tolerate a variety of functional groups\nand afford the corresponding products in moderate to good yields.\nDeuterium labeling experiments show that the functionalized hydrogen\nof styrenes was derived from the nitrogen–hydrogen of the substrates\nin the hydroamination. Preliminary mechanistic studies suggest that\nthe reactions may be a radical or a carbocation process.