文摘
Benzimidazole 2 bearing an N1-(biscyclohexylphosphine)ethyl tether cleaves [IrCp*Cl2]2 to yield the mononuclear phosphine complex [3]. Heating of [3] yields via a formal C/N tautomerization complex [4]Cl with a protic NHC. Complex [4]Cl can be N3-deprotonated to give its conjugate base [6]. Complex [6] is able to activate molecular hydrogen under mild conditions, leading to complex [5]BF4. The molecular structures of complexes [3], [4]Cl, [5]Cl, and [5]BF4 have been determined by X-ray diffraction studies.