Iron‐Only Hydrogenase Active Site Models Containing a Cysteinyl Group Coordinated through Its Sulfur Atom to One Iron Atom of the Diiron Subsite
Iron‐Only Hydrogenase Active Site Models Containing a Cysteinyl Group Coordinated through Its Sulfur Atom to One Iron Atom of the Diiron Subsite
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含有通过其硫原子与二铁子位点的一个铁原子配位的半胱氨酰基的纯铁氢化酶活性位点模型
DOI：
10.1002/ejic.200700821
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发表时间：
2008
影响因子：
2.3
通讯作者：
Q. Hu
中科院分区：
文献类型：
--
作者：
Li;Jian;Jing Yan;Hu;Xiang Luo;Q. Hu
我们已经开发了一种简单方便的方法合成的第一个H-簇模型，其中一个L-半胱氨酰基团是通过其硫原子配位到二铁子位的两个铁原子之一。该合成方法包括（i）处理Boc-保护的L-半胱氨酸酯Boc-NHCH（CH 2SH）CO2 Et（1，Boc =叔丁氧羰基）与EtONa反应，得到L-半胱氨酰硫醇盐NaSCH 2CH（NH-Boc）CO2 Et（2）;（ii）用[Cp（CO）2FeI]进一步处理2，得到金属硫醚配体Cp（CO）2FeSCH 2CH（NH-Boc）CO2 Et（3）;和（iii）处理母体二铁配合物[Fe 2（μ-SCH 2）2CH 2（CO）6]（4）、[Fe 2（μ-SCH 2）2N（tBu）（CO）6]（5），或[Fe 2（μ-SCH 2）2 N（C6 H4 OMe-p）（CO）6]（6）与Me 3 NO·2 H2O、配体3反应得到目标模型化合物[Fe 2（μ-SCH 2）2CH 2（CO）5（配体3）]（7）、[Fe 2（μ-SCH 2）2N（tBu）（CO）5（配体3）]（8）或[Fe 2（μ-SCH 2）2N（C6 H4 OMe-p）（CO）5（配体3）]（9）。所有新化合物2，3和7-9已通过元素分析和各种光谱技术表征。8的X射线衍射分析已经证实，这些模型包含半胱氨酰硫原子，其不仅与二铁亚位的一个Fe原子配位，而且与Cp（CO）2Fe部分的Fe原子配位以形成连接[FeCp-（μ-半胱氨酰-S）-Fe亚位]，其类似于天然酶中发现的[Fecubane-（μ-半胱氨酰-S）-Fe亚位]。此外，光谱和电化学测试进一步证明了[FeCp-（μ-半胱氨酰-S）-Fe亚基]可以在二铁亚基和Cp（CO）2Fe之间提供大量的电子交换.在电化学条件下，8已被证明是HOAc质子还原为二氢的催化剂，并提出了该催化反应的一种新类型的E* 2 E2 C机制。（© Wiley-VCH Verlag GmbH & Co. KGaA，69451魏因海姆，德国，2008）
We have developed a simple and convenient method for the synthesis of the first H-cluster models in which a L-cysteinyl group is coordinated to one of the two iron atoms of the diiron subsite through its sulfur atom. This synthetic method includes (i) treatment of the Boc-protected L-cysteine ester Boc-NHCH(CH2SH)CO2Et (1, Boc = tert-butoxycarbonyl) with EtONa to give the L-cysteinyl mercaptide NaSCH2CH(NH-Boc)CO2Et (2); (ii) further treatment of 2 with [Cp(CO)2FeI] to produce the metallothioether ligand Cp(CO)2FeSCH2CH(NH-Boc)CO2Et (3); and (iii) treatment of the parent diiron complex [Fe2(μ-SCH2)2CH2(CO)6] (4), [Fe2(μ-SCH2)2N(tBu)(CO)6] (5), or [Fe2(μ-SCH2)2N(C6H4OMe-p)(CO)6] (6) with Me3NO·2H2O followed by ligand 3 to afford the target model compounds [Fe2(μ-SCH2)2CH2(CO)5(ligand 3)] (7), [Fe2(μ-SCH2)2N(tBu)(CO)5(ligand 3)] (8), or [Fe2(μ-SCH2)2N(C6H4OMe-p)(CO)5(ligand 3)] (9), respectively. All the new compounds 2, 3, and 7–9 have been characterized by elemental analysis and various spectroscopic techniques. The X-ray diffraction analysis of 8 has confirmed that these models contain a cysteinyl sulfur atom not only coordinated to one Fe atom of the diiron subsite, but also to the Fe atom of the Cp(CO)2Fe moiety to form the linkage [FeCp-(μ-cysteinyl-S)-Fesubsite], which is similar to [Fecubane-(μ-cysteinyl-S)-Fesubsite] found in natural enzymes. In addition, spectroscopic and electrochemical measurements have further demonstrated that the linkage [FeCp-(μ-cysteinyl-S)-Fesubsite] can provide substantial electronic communication between the diiron subsite and the Cp(CO)2Fe moiety. Under electrochemical conditions, 8 has been shown to be a catalyst for HOAc proton reduction to dihydrogen, and a new type of E*2E2C mechanism for this catalytic reaction is suggested.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
影响因子：
11.3
作者：
A. Przybyla;Jeffery Robbins;N. Menon;H. D. Peck
通讯作者：
A. Przybyla;Jeffery Robbins;N. Menon;H. D. Peck