Direct Site‐Selective Difunctionalization of Pyrazoles

Abstract This study presents a protocol for the direct site‐selective difunctionalization of pyrazoles under mild reaction conditions. This protocol showcase a notable site‐selectivity and encompasses a wide substrate scope. Detailed mechanistic investigations elucidate the dual role of the sulfonium salt acting both as the reaction substrate and acid donor, thereby effectively catalyzing the reaction. The demonstrated one‐pot synthesis, scale‐up reaction and subsequent product modifications can assist in advancing the potential application of this protocol in organic synthesis and its associated domains.