Herein,
a mild metal-free and efficacious route for the synthesis
of biologically important 3-aryl oxindole derivatives is described.
Using Lambert salt-initiated hydroarylation of isatin, a diverse array
of monoarylated products, symmetrical/unsymmetrical double-arylated
products, and deoxygenated hydroarylated products could be synthesized
from the single starting substrate in good to excellent yields. A
preliminary mechanistic study revealed that the reaction proceeds
via a monoarylated product followed by a nucleophilic attack by another
electron-rich arene nucleophile under mild conditions. The potential
of newly synthesized symmetric/unsymmetric 3,3-disubstituted oxindole,
3-substituted 3-hydroxy oxindoles, 3,3-di(indolyl)indolin-2-ones,
and α-aryl oxindoles as valuable building blocks is further
illustrated.