Trifluoromethylthiolation of Aryl Iodides and Bromides Enabled by a Bench-Stable and Easy-To-Recover Dinuclear Palladium(I) Catalyst

While palladium catalysis is ubiquitous in modern chemical research, the recovery of the active transition-metal complex under routine laboratory applications is frequently challenging. Described herein is the concept of alternative cross-coupling cycles with a more robust (air-, moisture-, and thermally-stable) dinuclear Pd-I complex, thus avoiding the handling of sensitive Pd-0 species or ligands. Highly efficient CSCF3 coupling of a range of aryl iodides and bromides was achieved, and the recovery of the Pd-I complex was accomplished via simple open-atmosphere column chromatography. Kinetic and computational data support the feasibility of dinuclear Pd-I catalysis. A novel SCF3-bridged Pd-I dimer was isolated, characterized by X-ray crystallography, and verified to be a competent catalytic intermediate.