Base‐Activated Latent Heteroaromatic Sulfinates as Nucleophilic Coupling Partners in Palladium‐Catalyzed Cross‐Coupling Reactions

Heteroaromatic sulfinates are effective nucleophilic reagents in Pd(0)‐catalyzed cross‐coupling reactions with aryl halides. However, metal sulfinate salts can be challenging to purify, solubilize in reaction media, and are not tolerant to multi‐step transformations. Here we introduce base‐activated, latent sulfinate reagents: β‐nitrile and β‐ester sulfones. We show that under the cross‐coupling conditions, these species generate the sulfinate salt in situ, which then undergo efficient palladium‐catalyzed desulfinative cross‐coupling with (hetero)aryl bromides to deliver a broad range of biaryls. These latent sulfinate reagents have proven to be stable through multi‐step substrate elaboration, and amenable to scale‐up.