A novel one-pot multi-component synthesis of 3,3’-disubstituted oxindole and spirooxindole scaffolds via Sn-catalyzed C(sp3)–H functionalization of azaarenes by sequential Knoevenagel–Michael-cyclization reaction

Abstract

Sn-catalyzed C(sp³)–H bond functionalization of 2-methyl azaarenes/2-(azaaryl)methanes has been achieved for the first time in a one-pot multi-component reaction with isatin and active methylene compounds via tandem sequential Knoevenagel–Michael-intramolecular C–N cyclization. This strategy provides new cost-effective access to potent and biologically/medicinally important spirooxindoles/3,3′-disubstituted 2-oxindoles in good to excellent yields.