Synthesis, Structure, and Hydrogenolysis of Pyridine Dicarbene Iron Dialkyl Complexes.
Synthesis, Structure, and Hydrogenolysis of Pyridine Dicarbene Iron Dialkyl Complexes.
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DOI：
10.1021/acs.organomet.9b00382
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发表时间：
2019-08
期刊：
影响因子：
2.8
通讯作者：
S. M. Rummelt;Jonathan M. Darmon;R. Yu;P. Viereck;Tyler P. Pabst;Zoë R. Turner;Grant W. Margulieux;Shunlin Gu;P. Chirik
中科院分区：
文献类型：
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作者：
S. M. Rummelt;Jonathan M. Darmon;R. Yu;P. Viereck;Tyler P. Pabst;Zoë R. Turner;Grant W. Margulieux;Shunlin Gu;P. Chirik
开发了两种合成双（2-亚咪唑基）吡啶铁二烷基配合物（CNC）Fe（CH 2SiMe 3）2的方法。第一条路线由将两当量的LiCH 2SiMe 3添加到二卤化铁络合物（CNC）FeBr 2中组成，而第二条路线依赖于将游离CNC配体添加到容易制备的（py）2Fe（CH 2SiMe 3）2（py =吡啶）中。与芳基取代的CNC配体，八面体配合物的类型（Ar CNC）Fe（CH 2SiMe 3）2（N2）（Ar CNC =双（芳基咪唑-2-亚基）吡啶）被分离，其中的二氮配体占据的网站反式的CNC-螯合物的吡啶。相反，烷基取代的变体（tBuACNC）Fe（CH 2SiMe 3）2（tBuACNC = 2，6-（tBu-imidazol-2-ylidene）2 pyridine）被分离为缺乏二氮的五配位化合物。将（Ar CNC）Fe（CH 2SiMe 3）2（N2）衍生物暴露于H2气氛导致形成相应的氢化铁络合物（Ar CNC）FeH 4。这些化合物催化氘代苯溶剂和H2之间的氢同位素交换，生成（Ar CNC）Fe（Hn）（D4-n）（n = 0-4）的同位素体和同位素异构体。当（3，5-Me 2 MeCNC）Fe（CH 2SiMe 3）2（N2）（3，5-Me 2 MeCNC = 2，6-（2，4，6-Me 3-C6 H2-咪唑-2-亚基）2- 3，5-Me 2-吡啶）依次用H2和N2处理时，分离出相应的还原的二氮络合物（3，5-Me 2 MeCNC）Fe（N2）2。在将频哪醇硼烷加入到（3，5-Me 2 MeCNC）Fe（CH 2SiMe 3）2（N2）中之后也获得相同的产物。
Two methods for the synthesis of bis(imidazol-2-ylidene)pyridine iron dialkyl complexes, (CNC)Fe(CH2SiMe3)2, have been developed. The first route consists of addition of two equivalents of LiCH2SiMe3 to the iron dihalide complex, (CNC)FeBr2, while the second relies on addition of the free CNC ligand to readily-prepared (py)2Fe(CH2SiMe3)2 (py = pyridine). With aryl-substituted CNC ligands, octahedral complexes of the type ( Ar CNC)Fe(CH2SiMe3)2(N2) ( Ar CNC = bis(arylimidazol-2-ylidene)pyridine) were isolated, where the dinitrogen ligand occupies the site trans to the pyridine of the CNC-chelate. In contrast, the alkyl-substituted variant, (tBuACNC)Fe(CH2SiMe3)2 (tBuACNC = 2,6-(tBu-imidazol-2-ylidene)2pyridine) was isolated as the five-coordinate compound lacking dinitrogen. Exposure of the ( Ar CNC)Fe(CH2SiMe3)2(N2) derivatives to an H2 atmosphere resulted in formation of the corresponding iron hydride complexes ( Ar CNC)FeH4. These compounds catalyzed hydrogen isotope exchange between the deuterated benzene solvent and H2, generating isotopologues and isotopomers of ( Ar CNC)Fe(H n )(D4-n ) (n = 0-4). When (3,5-Me2 MesCNC)Fe(CH2SiMe3)2(N2) (3,5-Me2 MesCNC = 2,6-(2,4,6-Me3-C6H2-imidazol-2-ylidene)2-3,5-Me2-pyridine) was treated successively with H2 and then N2, the corresponding reduced dinitrogen complex (3,5-Me2 MesCNC)Fe(N2)2 was isolated. The same product was also obtained following addition of pinacolborane to (3,5-Me2 MesCNC)Fe(CH2SiMe3)2(N2).