Sulfur Contamination Due to Quenching of Halogenation Reactions with Sodium Thiosulfate: Resolution of Process Problems via Improved Quench Protocols

Many metal-mediated cross-couplings involve the use of organic halides, which are usually accessed by halogenation reactions. Cross-couplings are sensitive to the presence of impurities in the halides. This paper describes the origin of one such problematic impurity (sulfur) during the synthesis of organic halides and proposes alternatives to minimize or eliminate its formation.