A Serendipitous Non‐Metal‐Mediated Sp3 C─H Functionalization of 2‐Methyl Indolyl Scaffold for the Synthesis of 2‐Alkenyl Indoles*

Abstract

Challenging conventional methodologies, we pioneer a groundbreaking approach by C─H functionalization of sp³ carbon, which leads to the effective synthesis of 2‐alkenyl indole scaffold, bioactive olefin. Our study introduces an innovative approach by utilizing previously unexplored starting materials, expanding the possibilities of C─H functionalization. In contrast to previous studies that rely on metal‐based catalysts, our strategy harnesses a cost‐effective and environmentally friendly method. This functionalization was effectively promoted by NH₄Cl and MgSO₄, ensuring high efficiency, exceptional selectivity, and excellent yields under mild conditions. A series of spectroscopic techniques, including NMR (¹H, ¹³C, 19F, and DEPT‐135), IR, and mass spectrometry, were used for the detailed characterization of the synthesized 2‐alkenyl indoles. This method not only demonstrates broad functional group compatibility but also establishes a sustainable alternative to traditional metal‐catalyzed processes. By redefining the scope of this reaction, our work paves the way for future advancements in organic synthesis and biomedical applications.