A facile and efficient synthesis of polycyclic spiropyrrolidine oxindoles bearing mesityl oxide unit via a three-component 1,3-dipolar cycloaddition reaction
A facile and efficient methodology was developed for the synthesis of multifunctional polycyclic spiropyrrolidine oxindoles bearing mesityl oxide unit via a three-component 1,3-dipolar cycloaddition reaction of dienones 2 with azomethine ylides (thermally generated in situ from isatin derivatives and proline or thioproline). Products bearing adjacent four chiral carbon centers were smoothly obtained
Developed herein is a facile and efficient methodology toward the synthesis of novel turmerone motif-fused spiropyrrolidine oxindoles via a multicomponent 1,3-dipolarcycloaddition event of dienones 2 with azomethineylides (thermally generated in situ from isatin derivatives and sarcosine). Products bearing adjacent quaternary–tertiary centers were smoothly obtained in high yields (up to 93% yield)