Catalytic Transformations of Sulfonium Salts via C-S Bond Activation

After the 20-year dormant period since Liebeskind's seminal report, triorganosulfonium salts have now proved to be reliably useful surrogates of or complement to organic halides in a variety of transition-metal-catalyzed transformations. By necessity, my group developed Suzuki-Miyaura ring-opening arylation of sulfonium salts of dibenzothiophenes with tetraarylborates and Pd-catalyzed intramolecular C-H/C-S coupling. Following this starting point and experiencing the decent reactivity of sulfonium salts, in order to maximize the synthetic utility of organosulfur compounds, we successfully applied readily available sulfonium salts to Ni-catalyzed coupling with arylzinc reagents, Pd- or photoredox-catalyzed Mizoroki-Heck reaction, Pd-catalyzed alkoxycarbonylation, Pd-catalyzed Miyaura borylation, Ni-catalyzed reductive carboxylation, and Ni-catalyzed zincation. I sincerely hope this Personal Account will facilitate further development of reactions of triorganosulfonium salts which are difficult to achieve using conventional organic (pseudo)halides.