Iron‐Photocatalyzed Ligand‐to‐Metal Charge Transfer‐Driven Decarboxylative Giese‐Type Reactions Under Mild Conditions

Iron‐catalyzed ligand‐to‐metal charge transfer (LMCT) strategy provides a powerful platform for generating alkyl radicals from readily available carboxylic acids under mild photocatalytic conditions. Herein, we report an iron‐photocatalyzed, LMCT‐enabled decarboxylative Giese reaction that couples efficiently structurally diverse carboxylic acids with highly sensitive Michael acceptors. Key to this protocol is the use of a sterically hindered mild base in combination with tailored ligand systems. The method exhibits a broad substrate scope, including primary, secondary, and tertiary benzylic carboxylic acids, as well as challenging aliphatic carboxylic acids. Notably, it enables efficient functionalization of base‐sensitive Michael acceptors, such as maleimides, which have shown limited compatibility in prior methodologies. Furthermore, the applicability of this protocol to bioactive molecules highlights its potential for late‐stage modification. This work establishes a practical and complementary approach that expands the synthetic scope of iron‐photocatalyzed decarboxylative Giese‐type reactions.