Water-Controlled Divergent Mechanochemical Synthesis of β-Keto Sulfones and Alkynyl Sulfones: A Unified Approach

Herein, we report a water-controlled divergent mechanochemical sulfonylation of acetylenic carboxylic acids with sodium sulfinate salts. Under KI/TBHP-mediated ball-milling conditions, a low water content favors alkynyl sulfone formation, whereas excess water switches the reaction pathway to β-keto sulfones. The method accommodates aryl and alkyl sulfinate salts under transition-metal-, base-, and solvent-free conditions. Extension to α-methylstyrene substrates further demonstrates the broader applicability of this mechanochemical sulfonylation platform.