Regiocontrolled Synthesis of α‑Sulfonylmethyl o‑Nitrostyrenes via ZnI₂‑Mediated Sulfonylation and AgNO₂/Pd(PPh₃)₄‑Promoted o‑Nitration

We report herein the AgNO₂/Pd­(PPh₃)₄-promoted regiocontrolled o-nitration of α-sulfonylmethylstyrenes in MeNO₂ with good yields. The o-nitration process provides a series of sulfonyl o-nitrostyrenes. Substituted α-sulfonylmethylstyrenes were synthesized from ZnI₂-mediated sulfonylation of substituted α-methylstyrenes and sodium sulfinates (RSO₂Na) in MeCN with good to excellent yields. The structures of the key products were confirmed by X-ray crystallography. A plausible mechanism has been proposed herein.