A Zwitterionic Indylene with Ambiphilic Redox Reactivity

Extending transition-metal-like organometallic redox chemistry to indium remains a challenge in molecular main-group chemistry. Here, we report a zwitterionic indylene supported by an anionic bis(N-heterocyclic carbene)borate ligand that displays diverse redox reactivity. Computational and structural analyses reveal a relatively narrow HOMO–LUMO gap together with a stabilizing arene–In interaction involving a vacant indium p orbital, endowing the In(I) centre with complementary donor and acceptor character. This ambiphilicity is expressed experimentally through coordination and reactivity, with a broad range of bond-forming and redox processes, including cycloaddition and the direct oxidative addition of unactivated aryl–halogen bonds. These results expand the accessible reactivity of molecular In(I) and establish bis(NHC)borate ligands as a powerful platform for the development of indium redox organometallic chemistry.