Acidic ionic liquids catalyzed one-pot, pseudo five-component, and diastereoselective synthesis of highly functionalized piperidine derivatives

► Diastereoselective functionalized piperidine derivatives were synthesized. ► Anti-diastereomers of the products were prepared. ► Three reusable acidic ionic liquids were used as catalysts. ► The products were synthesized using ionic liquids for the first time. ► The reactions were carried out under green solvent-free conditions.