1,1 '-Butylenebis(3-sulfo-3H-imidazol-1-ium) hydrogensulfate: a versatile task-specific ionic liquid catalyst for the synthesis of 4H-pyran scaffolds through non-conventional process

摘要

In the present study, the catalytic efficiency of 1,1-butylenebis(3-sulfo-3H-imidazol-1-ium) hydrogensulfate (BBSI-HSO4) as a versatile sulfonic acid-functionalized ionic liquid was demonstrated for the one-pot mechanosynthesis of pyrano[4,3-b]-pyrans using planetary ball mill at room temperature under solvent-free conditions. This efficient mechanosynthesis approach to the 4H-pyran scaffolds displays a combination of the structure-activity relationship of ionic liquids with ecological benefits of a mechanocatalytic procedure. The ionic liquid was easily recycled and reused several times with no significant loss of its catalytic activity.