Ru/Ni Dual Catalytic Desulfinative Photoredox C_sp²–C_sp³ Cross-Coupling of Alkyl Sulfinate Salts and Aryl Halides

Abstract

A mild Ru/Ni dual catalytic desulfinative photoredox C_sp²-C_sp³ cross-coupling reaction of alkyl sulfinate salts with aryl halides has been developed. The optimized catalyst system, consisting of Ru(bpy)₃Cl₂, Ni(COD)₂, and DBU, smoothly mediates the coupling of a diverse set of secondary and primary nonactivated alkyl sulfinate salts with a broad range of electron-deficient aryl bromides, electron-rich aryl iodides, and heteroaryl bromides under irradiation with blue light. The procedure is ideal for late-stage introduction of alkyl groups on pharmaceutical intermediates, and the C_sp²-C_sp³ cross-coupling reaction allowed the rapid synthesis of caseine kinase 1δ inhibitor analogues via a parallel medicinal chemistry effort.