Upgrading Ethanol to n -Butanol in the Presence of Carbonate Catalyzed by a Cp*Ir Complex Bearing a Functional 2,2'-Carbonylbibenzimidazole Ligand.

Upgrading ethanol to n -butanol as biofuels is an important topic for sustainable chemistry. Herein, a Cp*Ir complex bearing a functional 2,2'-carbonylbibenzimidazole ligand [Cp*Ir(2,2'-COBiBzImH 2 )Cl][Cl] was designed and synthesized. In the presence of a catalyst (0.1 mol %) and Cs 2 CO 3 (6 mol %), the highest yield of updated n -butanol is up to 37% with 80% selectivity. NH units in the ligand are crucially important for the catalytic activity of the iridium complex.