Site-Selective Cross-Coupling of Remote Chlorides Enabled by Electrostatically-Directed Palladium Catalysis

Abstract

Control of site-selectivity in chemical reactions that occur remote from existing functionality remains a major challenge in synthetic chemistry. We describe a strategy that enables three of the most commonly used cross-coupling processes to occur with high site-selectivity on dichloroarenes which bear acidic functional groups. We have achieved this by repurposing an established sulfonylated phosphine ligand to exploit its inherent bifunctionality. Mechanistic studies suggest that the sulfonate group engages in attractive electrostatic interactions with the associated cation of deprotonated substrate, guiding cross-coupling to the chloride at the arene meta-position. This counterintuitive combination of anionic ligand and anionic substrate demonstrates an alternative design principle when considering applying non-covalent interactions to direct catalysis.