Simple and Direct sp<sup>3</sup> C–H Bond Arylation of Tetrahydroisoquinolines and Isochromans via 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone Oxidation under Mild Conditions

The 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated sp<sup>3</sup> C–H bond arylation of tetrahydroisoquinolines and isochromans is described. The corresponding products were facilely synthesized via a simple nucleophilic addition reaction between readily available aryl Grignard reagents and iminium (or oxonium) cations generated in situ by DDQ oxidation of tetrahydroisoquinolines (or isochromans) under mild conditions.