Counteranion-Controlled Chemodivergent Transfer-Hydrothiolation/Carbothiolation Utilizing Thioethers as Bifunctional Reagents

The pursuit of catalysis capable of forging C(sp3)-S bonds is extremely desired because these bonds have substantial importance in pharmaceuticals, functional materials, and organic synthesis. Hydrothiolation and carbothiolation of feedstock alkenes are among the most straightforward and prominent approaches to C(sp3)-S bond formations. However, hydrothiolation of unactivated alkenes typically proceeds in an anti-Markovnikov fashion, and carbothiolation relied on three-component coupling strategies using highly reactive pre-functionalized electrophilic sulfur sources and nucleophilic carbon sources. While carbothiolation of alkenes with a single, bifunctional reagent represents a concise and streamlined synthetic strategy for -alkyl organosulfur compounds, it has not been reported. Herein, by strategically using heterolytic cleavage of C(sp3)−S bond, we report a chemodivergent transfer-hydrothiolation and carbothiolation of alkenes with thioethers serving as bifunctional reagents. These catalytic systems can control the cleavage and reformation of strong C(sp3)−S -bonds. The chemo-control is achieved through careful selection of the counteranion associated with the Rh-centre. Counteranions with relatively strong basicity and coordinating ability, such as TfO-, promote an unusual Markovnikov transfer-thiol-ene reaction. Conversely, less basic and non-coordinating counteranions, such as BF4-, enable an unprecedented thioether-ene reaction, directly adding thioethers across alkenes. Mechanistic and computational studies elucidated that the coordination or non-coordination of counteranions on Rh can alter the basicity of thiolate, resulting in chemodivergence.