A simple and sustainable tetrabutylammonium fluoride (TBAF)-catalyzed synthesis of azaarene-substituted 3-hydroxy-2-oxindoles through sp<sup>3</sup> C–H functionalization
A green, practical, and metal-free protocol for direct addition of α-and γ-alkylazaarenes to isatins has been developed via sp3 C–H functionalization in water under controlled microwave radiation. This methodology provides a mild and fast route to biologically important azaarene-substituted 3-hydroxy-2-oxindoles in good to excellent yields.