Palladium-Catalyzed Desulfinative Cross-Coupling of Polyhalogenated Aryl Triflates with Aryl Sulfinate Salts: Inversion of Traditional Chemoselectivity

This paper presents the first general examples of palladium-catalyzed desulfinative cross-coupling reaction of polyhalogenated aryl triflates with aryl sulfinate salts showing an inversion of the conventional reactivity order of C-Br > C-Cl > C-OTf. The catalyst system, comprising of Pd(OAc)(2) and tBuPhSelectPhos, exhibited excellent catalytic reactivity and chemoselectivity toward this reaction. This reaction had a wide range of substrate scopes and provided a simple and efficient method for the construction of functionalized biaryl motifs. Notably, the C-H & BULL;& BULL;& BULL;Pd interaction from the methine hydrogen of the C2-cyclohexyl group of the indolyl phosphine ligand with the Pd center may contribute a key factor in reactivity and chemoselectivity. Assisting with density functional theory (DFT) calculations, the results revealed that the oxidative addition step in this reaction was a controlling-chemoselectivity step. [GRAPHICS]