Indium‐mediated Palladium‐catalyzed Allylic Alkylation of Isatins with Alkynes

Abstract

AbstractAn unprecedented indium‐mediated palladium‐catalyzed allylic alkylation of isatins with alkynes is disclosed. This reaction provides a new, practical, and straightforward route to access 3‐allyl‐3‐hydroxy‐2‐oxindoles in good yields with broad substrate scope and scalability, exhibiting high atom and step economy. A primary mechanistic study reveals that indium played two roles in the reaction, first as a reductant and second as a Lewis acid. Compared with previous methods, our strategy eliminated the steps for the separation and purification of the reaction intermediates, as well as pre‐installing leaving groups to allylic substrates. Moreover, our reaction did not employ moisture‐sensitive allylic metal species and stoichiometric oxidants.magnified image