Development of Persistent Cobalt(II)–Aryl Catalysts for C(sp2)–C(sp3) Cross-Coupling Involving Redox-Active Alkyl Electrophiles

Cross-coupling of alkyl electrophiles by first row transition metal catalysts represents a productive approach of incorporating C(sp3) fragments into pharmaceutically relevant organic molecules. This Account highlights the development of cobalt-catalyzed Negishi C(sp2)–C(sp3) cross-coupling reactions of redox active electrophiles, particularly thiol-derived unactivated alkyl(pyridyl)sulfones. Informed by catalyst characterization and mechanistic investigation, this account proposes key principles of substrate and catalyst design, which may enable development of future methodologies and robust cobalt catalysts for medicinal and process chemistry applications.