Phosphonium Phenolate Zwitterion vs Phosphonium Ylide: Synthesis, Characterization and Reactivity Study of a Trimethylphosphonium Phenolate Zwitterion

Abstract 4‐Methoxy‐3‐(trimethylphosphonio)phenolate was obtained from a regioselective addition of PMe 3 to p ‐quinone monoacetal. This compound undergoes hydrogen isotope exchange with D 2 O or CD 3 CN, and is capable of catalyzing H/D exchange of CD 3 CN with substrates bearing weakly acidic hydrogens. It exhibits similar reactivity to phosphorus ylides for olefinations of aldehydes. A possible tautomerization between the phosphonium phenolate zwitterion and phosphonium ylide is proposed for the first time to rationalize the unique reactivity. magnified image