Protecting Group‐Free Gold‐Catalyzed Synthesis of 2‐Acylidene‐3‐Oxindoles and Azaaurones via a Double Oxidation Strategy

Abstract A one‐pot synthesis of 2‐acylidene‐3‐oxindole and azaaurone derivatives starting from O ‐alkynylanilines and alkynes is presented. By means of oxidative gold catalysis the two starting materials are transferred to reactive intermediates that in situ form the target products. This double oxidation strategy enables a protecting group‐free step‐economic strategy towards these valuable substrate classes.