Acidic Ionic Liquids‐Catalyzed Dehydration Cross‐Coupling Reaction of Allyl Alcohols with Phosphine Oxides

Abstract In this study, a catalytic system for constructing C─P bonds from allyl alcohols and phosphine oxides was developed using an acidic ionic liquid as the catalyst and DMC (dimethyl carbonate) as the solvent, achieving a 95% yield of the target product. The acidity of the ionic liquid could affect the reaction activity with [BsPy][OTf] identified as the optimal catalyst. The cation, anion, and sulfonic acid side chain of the acidic ionic liquid exhibited synergistic effect on the catalytic performance. A gram‐scale experiment was performed smoothly, with a yield of 91%. UV–vis analysis and control experiments corroborated the formation of allyl carbocation and ruled out the occurrence of a disproportionation pathway in the transformation of allyl alcohols.