Olefin metathesis-active ruthenium complexes bearing a nucleophilic carbene ligand
Olefin metathesis-active ruthenium complexes bearing a nucleophilic carbene ligand
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DOI：
10.1021/ja9831352
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发表时间：
1999-03-31
影响因子：
15
通讯作者：
Petersen, JL
中科院分区：
文献类型：
--
作者：
Huang, JK;Stevens, ED;Petersen, JL
[Cp*RuCl]（4）（1，Cp* = eta（5）-C5 Me 5）与卡宾配体1，3-二（2，4，6-三甲基苯基）咪唑-2-亚基（IMes）反应，得到配位不饱和Cp*Ru（IMes）Cl（3）配合物，分离产率为86%。在这个系统中的溶液量热结果提供有关的卡宾配体，这是非常相似的那些PCy 3的电子给体性质的信息。从单晶X-射线研究的结构信息为配合物3允许与此配体的空间参数的测定。利用热化学信息预测了RuCl_2（=C（H）Ph）（PCy_3）（2）（1）与卡宾配体IMes发生取代反应后的热力学驱动力的大小，得到了高产率的RuCl_2（=C（H）Ph）（PCy_3）（IMes）（6）配合物。类似的混合卡宾/膦钌络合物RuCl 2（=C（H）Ph）（PPh 3）（IMes）也可以从RuCl 2（=C（H）Ph）（PPh 3）（2）和IMes配体中分离出来。单晶X射线衍射研究已进行了6。这些混合的膦/卡宾钌卡宾配合物的热稳定性已在60 ° C下在甲苯中进行了研究。以二乙基二烯丙基丙二酸酯的闭环复分解反应为例，评价了它们的催化活性。
The reaction of [Cp*RuCl](4) (1, Cp* = eta(5)-C5Me5) with the carbene ligand 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) affords a coordinatively unsaturated Cp*Ru(IMes)Cl (3) complex in 86% isolated yield. Solution calorimetric results in this system provide information concerning the electron donor properties of the carbene ligand, which are very similar to those of PCy3. Structural information from single-crystal X-ray studies for complex 3 allows the determination of steric parameters associated with this ligand. The thermochemical information is used to predict the magnitude of the enthalpic driving force behind substitution reactions involving RuCl2(=C(H)Ph)(PCy3)(2) (1) and the carbene ligand, IMes, affording the RuCl2(=C(H)Ph)(PCy3)(IMes) (6) complex in high yield. A similar mixed carbene/phosphine ruthenium complex, RuCl2(=C(H)Ph)(PPh3)(IMes), can also be isolated from RuCl2(=C(H)Ph)(PPh3)(2) and the IMes ligand. A single-crystal X-ray diffraction study has been performed on 6. The thermal stability of these mixed phosphine/carbene ruthenium carbene complexes has been studied at 60 degrees C in toluene. Their catalytic activity has been evaluated for the ring closing metathesis of diethyldiallylmalonate.