Synthesis of Bis(N-heterocyclic carbene) Complexes of Iron(II) and Their Application in Hydrosilylation and Transfer Hydrogenation
Synthesis of Bis(N-heterocyclic carbene) Complexes of Iron(II) and Their Application in Hydrosilylation and Transfer Hydrogenation
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DOI：
10.1021/om300298q
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发表时间：
2012-06
期刊：
影响因子：
2.8
通讯作者：
T. Hashimoto;S. Urban;Ryoko Hoshino;Y. Ohki;K. Tatsumi;F. Glorius
中科院分区：
文献类型：
--
作者：
T. Hashimoto;S. Urban;Ryoko Hoshino;Y. Ohki;K. Tatsumi;F. Glorius
用Fe{N(SiMe3)2}2与咪唑盐反应，制备了N-杂环羰基（NHC）二氯化铁（IMes）2FeCl2 （1a; IMes = 1,3-二（2,4,6-三甲基苯基）咪唑-2-乙基）和（IEtPh*）2FeCl2 （1b; IEtPh* = 1,3-二（(R)-1 ' -苯乙基）咪唑-2-乙基）。虽然1a的铁原子具有四面体几何形状，但通过MeLi处理1a，氯原子被甲基取代，导致形成方形平面配合物trans-(IMes)2FeMe2(2)。配合物1a、b和2的分子结构通过单晶x射线衍射分析得到。配合物1a、b和2是2′-乙酰萘酮转移加氢反应的良好催化剂前体，配合物2也能有效催化2′-乙酰萘酮的硅氢化反应。
N-heterocyclic carbene (NHC) adducts of iron dichloride, (IMes)2FeCl2 (1a; IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene) and (IEtPh*)2FeCl2 (1b; IEtPh* = 1,3-bis((R)-1′-phenylethyl)imidazol-2-ylidene), were prepared in good yields from the reactions of Fe{N(SiMe3)2}2 with imidazolium salts. While the iron atom of 1a has a tetrahedral geometry, replacement of the chlorides by methyl groups via treatment of 1a with MeLi led to the formation of the square-planar complex trans-(IMes)2FeMe2 (2). The molecular structures of complexes 1a,b and 2 were identified by means of single-crystal X-ray diffraction analysis. Complexes 1a,b and 2 are good catalyst precursors in the transfer hydrogenation of 2′-acetonaphthone, and complex 2 also efficiently catalyzes the hydrosilylation of 2′-acetonaphthone.