An Efficient and Green Stereoselective Synthesis of Functionalized 3-Indol-3-yl-oxoindolin-3-yl-3-acrylates via Nano-Fe3O4-Promoted One-Pot Four-Component Domino Reactions

Magnetic iron(III) oxide nanoparticles (Fe3O4 MNPs) have been used as a readily available, highly efficient, and recyclable catalyst for the green and stereoselective synthesis of novel functionalized 3-indol-3-yl-oxoindolin-3-yl-3-acrylates from a one-pot, two-step, four-component reaction of arylamines, alkyl propiolates, isatin, and indole in EtOH under reflux conditions in good yields. The domino environmentally friendly methodology with excellent green chemistry credentials, such as using the low loading of reusable, nontoxic, easy to handle catalyst, shorter reaction time, avoidance of hazardous organic solvents, and straightforward workup (the catalyst can be easily separated from the reaction mixture by an external magnet), may find a wide range of applications.