Building an All Carbon Quaternary Center via Redox-Neutral Geminal Dual C–H Functionalization of Oxindoles

Reported here is a catalytic redox-neutral geminal dual C-H functionalization of oxindoles with two distinct aromatics using anilines. The reaction proceeded through a pluripotent tetra-substituted alkene intermediate via an extended resonance stabilized carbocation. It furnished wide chemical space around oxindoles with the generation of all carbon quaternary centers (>35 examples) in good to excellent yields. The developed process is highly regioselective and scalable, and the conditions are environmentally benign in nature.