Coumarin-Rewired Benzothiophenes: Skeletal Editing for Peripheral Heterofunctionalization

A single-atom skeletal editing strategy is reported for dual-site heterofunctionalization of benzothiophenes. The transformation involves a sulfonium intermediate formed with coumarin, triggering sequential ring opening and fusion to reconstruct the benzothiophene scaffold. Strategic tuning of the reaction conditions enables the coumarin module to function as a selective benzoyl or carboxyl donor for peripheral modification. This method facilitates efficient framework remodeling and peripheral diversification, bypassing selectivity challenges inherent in conventional C-H functionalization.