Palladium-Catalyzed C(sp2)-H Olefination of Free Primary and Secondary 2-Phenylethylamines: Access to Tetrahydroisoquinolines.

A rapid construction of THIQs by a Pd(II)-catalyzed C(sp2)-H olefination of free primary and secondary 2-phenylethylamines with high step- and atom-economy was reported. Notably, no substituent was required at the α-position to the amino group of the 2-phenylethylamines. The substrate scope was broad, and the reaction could also be applied to generate THIQs from the biologically active molecules such as the drug molecule baclofen and phenylalanine ester.