Bronsted Acidic Ionic Liquids as Efficient Catalysts and Mediums for the Synthesis of Half-esters:Structure-catalytic Selectivity Relationship

Br(A)nsted acidic ionic liquids based on imidazolium cation werc employed as efficient catalysts and mediums for the ring opening of phthalic anhydride to synthesize half-esters.Good yields.short reaction time and mild reaction condition were achieved.Lower acidity of ionic liquid resulted in higher catalytic selectivity in the synthesis of half-esters.The minimum-energy geometries of sulfonic acid-functionalized ionic liquids based on imidazolium cation revealed that their acidities and catalytic selectivity in the synthesis of half-esters were related to their structures.