Palladium-Catalyzed Cross-Electrophile Couplings of Aryl Thianthrenium Salts with Alkyl Bromides and Chlorides

An effective Pd-catalyzed C sp 2 –C sp 3 cross-electrophile coupling between aryl thianthrenium salts and alkyl bromides (and chlorides) was developed. The reactions proceeded efficiently via C–S bond functionalization at room temperature under the assistance of a Pd catalyst, phosphine ligand, Mg mediator, ZnCl 2, and LiCl in THF, entailing the convenient construction of a broad range of structurally diverse alkylated arenes in modest to good yields. The coupling protocol exhibited broad substrate scope and good functionality tolerance, and it could be easily scaled up and be utilized in the postmodification of complex molecules. Mechanistic studies suggested that the in situ-formed alkyl zinc reagent presumably functioned as the pivotal intermediate of the reductive electrophile cross-coupling.