Synthesis of an axially chiral Ir–NHC complex derived from BINAM

The Ir–NHC complex 6 was successfully synthesized from the reaction of axially chiral binaphthyl dibenzimidazolium salt 5 with [Ir(COD)Cl]₂ (COD = 1,5‐cyclooctadiene) in tetrahydrofuran in the presence of KO^tBu base under reflux. Its unique crystal structure is unambiguously disclosed by X‐ray diffraction. Complex 6 is orthorhombic, with space group P2₁2₁2₁, unit cell dimensions a = 12.1406(16) Å, b = 19.110(3) Å, c = 20.312(3) Å, α = β = γ = 90° and volume 4712.6(11) ų, Z = 4, D_calc = 1.930 Mg m^?3. Copyright © 2004 John Wiley & Sons, Ltd.