Metal-Free Photoredox-Catalyzed Anti-Markovnikov Phosphinothiolation of Styrenes: Chemodivergent Access to <i>S</i> -Alkyl-phosphinothioates and β-Keto-phosphinothioates

Anti-Markovnikov hydrophosphinothiolation of alkenes is quite challenging and is rarely explored. Herein, we report a visible-light-mediated metal-free multicomponent coupling strategy for the anti-Markovnikov hydrophosphinothiolation of styrenes, utilizing readily accessible phosphine-oxides and elemental sulfur. This operationally simple protocol delivers a broad range of S -alkyl-phosphinothioates with excellent selectivity and atom economy. Fine-tuning the reaction parameters tweaks the pathway to afford β-keto-phosphinothioates, expanding the synthetic utility of this transformation to access chemodivergent products.