Versatile benzannulation strategies with vinyl sulfoxonium ylides and electron-deficient alkenes/alkynes.

Arenes are prominent structural motifs in pharmaceuticals, natural products, and functional materials, yet their synthesis often demands multistep procedures and harsh conditions. Benzannulation offers a step-economical alternative, enabling the direct construction of polyfunctionalized arenes from acyclic precursors with high regioselectivity and efficiency. Among the diverse benzannulation strategies, vinyl sulfoxonium ylides (VSYs) have emerged as versatile synthons, containing an electron-rich ylide group and an electron-deficient carbonyl group at the two ends of the styrene unit that facilitate a broad range of transformations. This review highlights recent advancements in reagent- and condition-controlled benzannulation reactions of VSYs with alkenes and alkynes, enabling divergent access to structurally distinct arene scaffolds.