Sulfur-directed palladium-catalyzed C(sp3)-H α-arylation of 3-pyrrolines: easy access to diverse polysubstituted pyrrolidines

A sulfur-directed palladium-catalyzed C(sp(3))-H alpha-arylation of 3-pyrrolines has been disclosed by installing a thioacyl group as the directing group. The arylation reactions using arylboronic acids as coupling partners provided a variety of 2-aryl-3-pyrolines in moderate to good yields. Moreover, the alpha-arylated products were readily converted to various synthetically useful 3-pyrroline and pyrrolidine derivatives, especially polysubstituted pyrrolidines.