Redox Noninnocence of a β-Diketiminate Enabling Electron Transfer Catalysis

The β-diketiminate is an iconic class of ligand that spans a wide variety of metal complexes across the periodic table. Compared to the well-evaluated redox noninnocent nature of several other ligand classes, detectable redox activity for β-diketiminate is scarce. The development of an effective homogeneous catalyst leveraging the redox reservoir property of a β-diketiminate backbone has never been achieved. Herein, we present a copper bis(β-diketiminate) complex that enables the completely ligand-centric redox for steering alkoxycarboxylation at the 2-position of indole. The success of the reaction pivots on the electron reservoir property of an electron-rich β-diketiminate that can facilitate single electron transfer to reductively cleave a C─Br bond. X-ray structure determination of the complex, along with CV, EPR, and magnetic susceptibility, describes the electronic structure of the catalyst molecule and proves the ligand's predominant role in such single-electron transfer catalysis.