Palladium-Catalyzed Direct Arylation of Methyl Sulfoxides with Aryl Halides

The palladium-catalyzed alpha-arylation of unactivated sulfoxides has been developed. The weakly acidic alpha-protons of sulfoxides are reversibly deprotonated by LiOtBu, and a palladium phosphine complex facilitates the arylation. A variety of aryl methyl sulfoxides were coupled with aryl bromides. More challenging coupling partners, such as alkyl methyl sulfoxides (including dimethyl sulfoxide) and aryl chlorides proved to be suitable under the optimized conditions. This method was utilized to synthesize bioactive benzyl sulfoxide intermediates.