Modular Functionalization of Arenes in a Triply Selective Sequence: Rapid C(sp²) and C(sp³) Coupling of C−Br, C−OTf, and C−Cl Bonds Enabled by a Single Palladium(I) Dimer

Abstract

Full control over multiple competing coupling sites would enable straightforward access to densely functionalized compound libraries. Historically, the site selection in Pd⁰ -catalyzed functionalizations of poly(pseudo)halogenated arenes has been unpredictable, being dependent on the employed catalyst, the reaction conditions, and the substrate itself. Building on our previous report of C-Br-selective functionalization in the presence of C-OTf and C-Cl bonds, we herein complete the sequence and demonstrate the first general arylations and alkylations of C-OTf bonds (in <10 min), followed by functionalization of the C-Cl site (in <25 min), at room temperature using the same air- and moisture-stable Pd^I dimer. This allowed the realization of the first general and triply selective sequential C-C coupling (in 2D and 3D space) of C-Br followed by C-OTf and then C-Cl bonds.