Carmona Daniel, Pilar Lamata M, Viguri Fernando, Rodríguez Ricardo, Lahoz Fernando J, Dobrinovitch Isabel T, Oro Luis A
Departamento de Química Inorgánica, Instituto Universitario de Catálisis Homogénea, Universidad de Zaragoza-Consejo Superior de Investigaciones Científicas, 50009 Zaragoza, Spain.
Dalton Trans. 2007 May 21(19):1911-21. doi: 10.1039/b618720j.
Reaction of the dimer [(CpIrCl)2(P-Cl)2] with chiral pyridylamino ligands (pyam, L1-L5) in the presence of NaSbF6 gave complexes [CpIrCl(pyam)][SbF6] 1-5 as diastereomeric mixtures, which have been fully characterised, including the X-ray molecular structure determination of the complexes (S(Ir),R(N),R(C))-[CpIrClL1][SbF6] 1a and (R(Ir),S(N),S(C))-[CpIrClL5][SbF6] 5a. Treatment of these cations with AgSbF6 affords the corresponding aqua species [CpIr(pyam)(H2O)][SbF6]2 6-10 which have been also fully characterised. The molecular structure of the complex (S(Ir),R(N),R(C))-[CpIrL,(H2O)][SbF6]2 6 has been determined by X-ray diffractometric methods. The aqua complexes [CpIr(pyam)(H2O)][SbF6]2 (6, pyam = L2 (7), L3 (8)) evolve to the cyclometallated species [CpIr{kappa3(N,N',C)-(R)-(C6H4)CH(CH3)NHCH2C5NH4}][SbF6] (11), [CpIr{kappa3(N,N',C)-(R)-(C10H6)CH(CH3)-NHCH2C5NH4)}][SbF6] (12), and [CpIr{kappa3(N,N',C)-(R)-(C10H6)CH(CH3)NHCH2C9NH6)}][SbF6] (13) respectively, via intramolecular activation of an ortho C-H aryl bond. Complexes 6-10 are enantioselective catalysts for the Diels-Alder reaction between methacrolein and cyclopentadiene. Reaction occurs rapidly at room temperature with good exo : endo selectivity (from 81 : 19 to 98 : 2) and moderate enantioselectivity (up to 72%). The involved intermediate Lewis acid-dienophile compounds [Cp*Ir(pyam)(methacrolein)][SbF]2 (pyam = L4 (14), L5 (15)) have been isolated and characterised.
二聚体[(CpIrCl)₂(P-Cl)₂]在手性吡啶基氨基配体（pyam，L1-L5）存在下与NaSbF₆反应，生成非对映异构体混合物的配合物[CpIrCl(pyam)][SbF₆] 1-5，这些配合物已得到充分表征，包括配合物(S(Ir),R(N),R(C))-[CpIrClL1][SbF₆] 1a和(R(Ir),S(N),S(C))-[CpIrClL5][SbF₆] 5a的X射线分子结构测定。用AgSbF₆处理这些阳离子可得到相应的水合物种[CpIr(pyam)(H₂O)][SbF₆]₂ 6-10，它们也已得到充分表征。配合物(S(Ir),R(N),R(C))-[CpIrL,(H₂O)][SbF₆]₂ 6的分子结构已通过X射线衍射法测定。水合配合物[CpIr(pyam)(H₂O)][SbF₆]₂（6，pyam = L2 (7)，L3 (8)）通过邻位C-H芳基键的分子内活化分别转化为环金属化物种[CpIr{κ³(N,N',C)-(R)-(C₆H₄)CH(CH₃)NHCH₂C₅NH₄}][SbF₆] (11)、[CpIr{κ³(N,N',C)-(R)-(C₁₀H₆)CH(CH₃)-NHCH₂C₅NH₄)}][SbF₆] (12)和[CpIr{κ³(N,N',C)-(R)-(C₁₀H₆)CH(CH₃)NHCH₂C₉NH₆)}][SbF₆] (13)。配合物6-10是甲基丙烯醛与环戊二烯之间Diels-Alder反应的对映选择性催化剂。反应在室温下迅速发生，具有良好的外型：内型选择性（从81:19到98:2）和中等对映选择性（高达72%）。所涉及的中间体路易斯酸-亲双烯体化合物[Cp*Ir(pyam)(甲基丙烯醛)][SbF]₂（pyam = L4 (14)，L5 (15)）已被分离和表征。
