Highly ordered mesoporous functionalized pyridinium protic ionic liquid framework as a highly efficient catalytic system in chemoselective thioacetalization of carbonyl compounds under solvent-free conditions

Abstract

Dithioacetals are a well-known class of organic compounds as both protecting group for the carbonyl compounds and valuable synthons for organic synthesis. Polysiloxane acidic ionic liquids containing pyridinium trifluoroacetate salts (PMO-Py-IL) as organic-inorganic hybrid nanomaterial was studied for the transformation reaction of dithiols to aldehydes and ketones. Cyclic dithiacetals were obtained in excellent yield under mild reaction conditions. PMO-Py-IL nanocatalyst also demonstrated to be an efficient catalyst in chemoselective dithiacetalization of aldehydes in the presence of ketones. The catalyst could be separated and reused in several reaction runs without any remarkable reduction in its catalytic activity. Mild reaction conditions, short reaction time, cost effectiveness, eco-friendly nature with high chemoselectivity, and ease of isolation of the product make the present procedure sustainable and effective.