2,2'-Carbonylbibenzimidazole Ligand-Based Hyper-Cross-Linked Polymer-Supported Iridium Complex: A Recyclable Metal-Polymer Ligand Bifunctional Catalyst for Upgrading Ethanol to n-Butanol.

A metal-polymer ligand bifunctional catalyst Cp*Ir@HCPs-(2,2'-COBiBzlmH2) was constructed by immobilizing [Cp*IrCl2] onto a 2,2'-carbonylbibenzimidazole-functionalized hyper-cross-linked polymer support. Under optimized conditions (0.015 mol % Ir loading, 6 mol % Cs2CO3, 150 °C, and 36 h), this heterogeneous system afforded n-butanol in up to 37% yield. Mechanistic investigations and density functional theory calculations were further conducted to gain insights into the catalytic pathway. The catalyst could be reused for six consecutive runs without significant activity decay.