Nickel‐Catalyzed Sulfonylation of Aryl Bromides Enabled by Potassium Metabisulfite as a Uniquely Effective SO2 Surrogate

Abstract

AbstractThe development and mechanistic investigation of a nickel‐catalyzed sulfonylation of aryl bromides is disclosed. The reaction proceeds in good yields for a variety of substrates and utilizes an inexpensive, stench‐free, inorganic sulfur salt (K2S2O5) as a uniquely effective SO2 surrogate. The active oxidative addition complex was synthesized, isolated, and fully characterized by a combination of NMR spectroscopy and X‐ray crystallography analysis. The use of the isolated oxidative addition complex in both stoichiometric and catalytic reactions revealed that SO2 insertion occurs via dissolved SO2, likely released upon thermal decomposition of K2S2O5. Key to the success of the reaction is the role of K2S2O5 as a reservoir of SO2 that is slowly released, thus preventing catalyst poisoning.