Palladium‐Catalyzed One‐Pot Synthesis of C2‐Quaternary Indolin‐3‐ones via 1H‐indole‐3‐sulfonates Generated in Situ from 2‐Alkynyl Arylazides and Sulfonic Acids

A novel method for the synthesis of C2-quaternary indole-3-ones via palladium-catalyzed one-pot transformation of 2-alkynyl arylazides is described. The reaction produced in moderate to excellent yields under mild conditions. This novel rearrangement of 1-H-indole-3-sulfonates represents an important contribution to the application of aryl sulfonates.