A General Catalytic Sulfide‐based Electron Donor–Acceptor Complex Platform for Decarboxylative Transformations of <i>N</i>‐Hydroxyphthalimide Esters

This study develops a general platform using a catalytic electron donor–acceptor (EDA) system, which combines inexpensive and readily available sulfides and N‐hydroxyphthalimide esters. This general platform facilitates various redox‐neutral and net‐reductive reactions, including intramolecular cyclization, hydrodecarboxylation, hydroalkylation, heterocyclic synthesis, and C–H imidation of arenes, through simple operations. For example, the intramolecular cyclization of the N‐hydroxyphthalimide (NHPI) ester derivatives achieves yields of up to 84%, while hydrodecarboxylation and hydroalkylation reactions proceed with yields of 78% and 81%, respectively. Heterocyclic synthesis and C–H imidation are also accomplished with yields of up to 76% and 74%, respectively. Mechanistic investigations reveal that, in the presence of Li ions, the distance between the sulfur atom and the closest atom of the NHPI ester (1a) in the EDA complex decreases from 3.43 to 3.29 Å, whereas the HOMO–LUMO gap decreases from 5.42 to 5.32 eV. These results confirm that lithium ions serve as Lewis acids, enhancing the interaction within the EDA complex. The robustness of this catalytic EDA platform is demonstrated by its compatibility with water and air, conditions that challenge conventional photoredox platforms. This study highlights sulfides as effective catalytic electron donors.