Direct Alkylation and Acylation of 2H‐Indazoles Using Aldehydes under Metal‐Free Conditions

Abstract A simple, effective, and direct alkylation and acylation of indazoles using aldehydes under metal‐free conditions has been developed. This regioselective alkylation/acylation protocol can proceed under mild conditions, tolerate a wide range of functional groups, and deliver multifunctional 2 H ‐indazole derivatives with high efficiency. Mechanism studies indicated that a radical process was involved.