Merging carboxylic acids with metal-catalyzed hydrogen atom transfer (MHAT) chemistry via alkene-functionalized redox-active esters

The development of general methods for radical bond formation remains a central goal in organic synthesis, particularly those that enable diverse transformations from simple, abundant starting materials. Here, we report a unified approach that merges carboxylic acid activation with metal-catalyzed hydrogen atom transfer (MHAT) to enable the generation and selective functionalization of open-shell intermediates under a single catalytic system. Key to this strategy is the design of a redox-active ester bearing an internal alkene "trigger" that undergoes regioselective MHAT using Fe(acac)₃ and phenylsilane, leading to decarboxylative radical formation under mild conditions. This platform supports the synthesis of a wide array of products via C-C, C-heteroatom, and C-H bond-forming processes, accessed solely by varying the radical acceptor. Notably, it enables the formation of linear coupling products-previously inaccessible under conventional MHAT conditions-via access to primary radical intermediates. We anticipate that this conceptually distinct mode of activation will find applications in modular synthesis, late-stage functionalization, and the generation of medicinally relevant analogs.