Copper-Mediated C(sp2)–H Thiolation of Free Amines Enabled by a Transient Directing Group

A copper-mediated C-H thiolation reaction of benzylamines has been developed using a transient directing group strategy. In this reaction, picolinaldehyde was used as the catalyst, which forms a transient imine directing group in situ with benzylamines to facilitate C-H activation. This method not only provides a straightforward route to aryl sulfides but also represents one of the rare examples of first-row transition metal-mediated C-H functionalization via a transient directing group approach. The work highlights the potential of cost-effective copper catalysts in enabling challenging C-S bond formations, advancing the field of sustainable C-H functionalization.