Inter- and Intramolecular Activation of Aromatic C−H Bonds by Diphosphine and Hydrido-Bridged Dinuclear Iridium Complexes

Reactions of [(Cp*Ir)2(μ-dmpm)(μ-H)2]2+ (1) with NaOtBu in aromatic solvent at room temperature give [(Cp*Ir)(H)(μ-dmpm)(μ-H)(Cp*Ir)(Ar)]+ [Ar = Ph (3), p-Tol (4a), m-Tol (4b), 2-furanyl (5a), 3-furanyl (5b)] via intermolecular aromatic C−H activation. Treatment of [(Cp*Ir)2(μ-dppm)(μ-H)2]2+ (2) with base (Et2NH) results in intramolecular C−H activation of the phenyl group in the dppm ligand to give [(Cp*Ir)(H){μ-PPh(C6H4)CH2PPh2}(μ-H)(Cp*Ir)]+ (6). The structures of 3, 5a, and 6 have been determined by X-ray diffraction methods.

在芳香族溶剂中，室温条件下，[(五甲基环戊二烯基合铱)₂(μ-桥联双(二甲基膦基)甲烷(dmpm))(μ-桥联氢)₂]²⁺ (1) 与叔丁醇钠(NaOtBu)发生反应，通过分子间芳香C−H活化途径，生成配合物[(Cp*Ir)(H)(μ-dmpm)(μ-H)(Cp*Ir)(Ar)]⁺ [其中Ar = 苯基(Ph, 3)、对甲苯基(p-Tol, 4a)、间甲苯基(m-Tol, 4b)、2-呋喃基(5a)、3-呋喃基(5b)]。将[(五甲基环戊二烯基合铱)₂(μ-桥联双(二苯基膦基)甲烷(dppm))(μ-桥联氢)₂]²⁺ (2) 与碱（二乙胺(Et₂NH)）反应后，其dppm配体上的苯基发生分子内C−H活化，生成配合物[(Cp*Ir)(H){μ-PPh(C₆H₄)CH₂PPh₂}(μ-H)(Cp*Ir)]⁺ (6)。通过X射线衍射(X-ray diffraction)法测定了配合物3、5a及6的晶体结构。