One-pot synthesis of 2-amino-3-cyano-4<i>H</i>-pyrans and pyran-annulated heterocycles using sodium citrate as an organo-salt based catalyst in aqueous ethanol

Sodium citrate as a highly efficient catalyst is developed for the synthesis of functionalized 2-amino-3-cyano-4H-pyrans and pyran-annulated heterocycles. This method involves one-pot three-component reaction aromatic aldehydes, malononitrile 1,3-dicarbonyl compounds with EtOH: H2O (1:1 v/v) solvent under room temperature. protocol presents several advantages such shorter time, utilization eco-friendly solvents, operational simplicity, mild conditions, maximum product yield. Moreover, use sodium an easily available, cheap benign plays pivotal role from green perspective, considering its high recyclability easy recovery. Therefore, this present methodology offers numerous possibilities in terms large-scale industrial syntheses or application to organic conversions. Furthermore, theoretical studies on mechanistic pathway formation 4aa were also carried out determine catalytic feasibility DFT method, using B3LYP functional.