Synthesis and reactivity of [M(η3-allyl)(η2-amidinato)(CO)2(phosphonium ylide)] (M = Mo, W): Investigation of the ligand properties of phosphonium ylides
Synthesis and reactivity of [M(η3-allyl)(η2-amidinato)(CO)2(phosphonium ylide)] (M = Mo, W): Investigation of the ligand properties of phosphonium ylides
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[M(η3-烯丙基)(η2-脒基)(CO)2(鏻叶立德)] (M = Mo, W) 的合成和反应性：研究鏻叶立德的配体性质
DOI：
10.1016/j.ica.2017.11.019
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发表时间：
2018
影响因子：
2.8
通讯作者：
Yamaguchi Yoshitaka
中科院分区：
文献类型：
--
作者：
Takaki Daichi;Ogata Kenichi;Kurihara Youji;Ueda Kazuyoshi;Hashimoto Toru;Yamaguchi Yoshitaka
通过脒基（吡啶）配合物[M（η3-烯丙基）{η2-（NPh）2CH}（CO）2（NC_5 H_5）]（M = Mo：1-Mo和M = W：1-W）与磷鎓叶立德CH_2 PR_3（R = Me，Ph）的反应制备了钼和钨的磷鎓叶立德配合物[M（η3-烯丙基）{η2-（NPh）2CH}（CO）2（CH_2 PR_3）]（M = Mo，R = Me：2a-Mo; M = Mo，R = Ph：2b-Mo，和M = W，R = Me：2a-W），其中磷鎓叶立德CH_2 PR_3（R = Me，Ph）是通过相应的磷鎓盐与正丁基锂反应原位生成的。这些配合物的特征在于光谱，以及通过X-射线衍射。磷叶立德配体比氮杂环卡宾或膦配体对金属具有更强的给电子能力。这一趋势得到了光谱数据和DFT计算结果的比较的支持。我们还研究了膦叶立德配合物2-Mo与PEt 3和NHC等双电子给体的反应性。在PPh 3叶立德配合物（2b-Mo）的情况下，叶立德配体对双电子给体的取代反应干净地发生，得到相应的配合物。另一方面，在PMe 3叶立德络合物（2a-Mo）中，形成了取代的络合物，但未反应的叶立德络合物2a-Mo也存在于反应混合物中。这些结果表明，磷原子上的取代基影响磷叶立德的键强度。
Phosphonium ylide complexes of Mo and W formulated as [M(η3-allyl){η2-(NPh)2CH}(CO)2(CH2PR3)] (M = Mo, R = Me:2a-Mo; M = Mo, R = Ph:2b-Mo, and M = W, R = Me:2a-W) were prepared by the reaction of amidinato(pyridine) complex, [M(η3-allyl){η2-(NPh)2CH}(CO)2(NC5H5)] (M = Mo:1-Moand M = W:1-W), with a phosphonium ylide, CH2PR3(R = Me, Ph), which was generated in situ by the reaction of the corresponding phosphonium salt withnBuLi. These complexes were characterized spectroscopically, as well as by the X-ray diffraction. The phosphonium ylide ligand shows stronger electron donating ability toward the metal thanN-heterocyclic carbene or phosphine ligands. This trend is supported by the comparison of the spectroscopic data and the DFT calculations. We also investigated the reactivity of the phosphonium ylide complexes2-Mowith two-electron donors such as PEt3and NHC. In the case of the PPh3ylide complex (2b-Mo), the substitution reaction of the ylide ligand for the two-electron donors took place cleanly to yield the corresponding complexes. On the other hand, in the PMe3ylide complex (2a-Mo), the substituted complexes formed but the unreacted ylide complex2a-Mowas also present in the reaction mixture. These results show that the bond strength of the M-C(phosphonium ylide) bond is affected by the substituents on the phosphorus atom.