Cyclopentadienone iron alcohol complexes: synthesis, reactivity, and implications for the mechanism of iron-catalyzed hydrogenation of aldehydes.
Cyclopentadienone iron alcohol complexes: synthesis, reactivity, and implications for the mechanism of iron-catalyzed hydrogenation of aldehydes.
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DOI：
10.1021/ja808683z
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发表时间：
2009-02-25
影响因子：
15
通讯作者：
Guan H
中科院分区：
文献类型：
--
作者：
Casey CP;Guan H
通过[2，5-（SiMe 3）2- 3，4-（CH 2）4（η5-C4 COH）]Fe（CO）2 H（3）与醛反应生成了环己烯酮铁醇配合物，并用1HNMR、13 CNMR和IR对其结构进行了表征。苯甲醇配合物[2，5-（SiMe 3）2- 3，4-（CH 2）4（η5-C4 C =O）]Fe（CO）2（HOCH 2C 6 H5）（6-H）也通过X射线晶体学进行了表征。这些醇配合物是热不稳定的，并且易于解离配位醇。醇配体很容易被其他配体如PhCN、吡啶和PPh 3取代。在H2存在下醇配体的解离导致氢化铁3的形成。醛的还原3进行了潜在的分子间和分子内陷阱的存在下。在4-甲基苄醇作为潜在的分子间捕获剂的存在下，3与PhCHO的反应最初仅产生新形成的苄醇的铁络合物6-H。然而，3与具有潜在的分子内醇捕获剂的4-（HOCD 2）C6 H4 CHO（11-d2）反应，得到两种醇络合物，一种与新形成的醇配位到铁，另一种与捕获醇配位。分子内捕获实验支持的机制，涉及协同转移的质子从OH和氢化物从Fe的3醛。研究了3催化苯甲醛加氢反应的动力学和反应机理.
Cyclopentadienone iron alcohol complexes generated from the reactions of [2,5-(SiMe3)2-3,4-(CH2)4(η5-C4COH)]Fe(CO)2H (3) and aldehydes were characterized by 1H NMR, 13C NMR, and IR spectroscopy. The benzyl alcohol complex [2,5-(SiMe3)2-3,4-(CH2)4(η5-C4C=O)]Fe(CO)2(HOCH2C6H5) (6-H) was also characterized by X-ray crystallography. These alcohol complexes are thermally unstable and prone to dissociate the coordinated alcohols. The alcohol ligand is easily replaced by other ligands such as PhCN, pyridine, and PPh3. Dissociation of the alcohol ligand in the presence of H2 leads to the formation of iron hydride 3. The reduction of aldehydes by 3 was carried out in the presence of both potential intermolecular and intramolecular traps. The reaction of 3 with PhCHO in the presence of 4-methylbenzyl alcohol as a potential intermolecular trapping agent initially produced only iron complex 6-H of the newly formed benzyl alcohol. However, the reaction of 3 with 4-(HOCD2)C6H4CHO (11-d2), which possesses a potential intramolecular alcohol trapping agent, afforded two alcohol complexes, one with the newly formed alcohol coordinated to iron and the other with the trapping alcohol coordinated. The intramolecular trapping experiments support a mechanism involving concerted transfer of a proton from OH and hydride from Fe of 3 to aldehydes. The kinetics and mechanism of the hydrogenation of benzaldehyde catalyzed by 3 are presented.
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DOI：
10.1139/v05-140
发表时间：
2005-09-01
期刊：
CANADIAN JOURNAL OF CHEMISTRY-REVUE CANADIENNE DE CHIMIE
影响因子：
--
作者：
Casey, CP;Johnson, JB
通讯作者：
Johnson, JB
影响因子：
3.6
作者：
Csjernyik, G;Éll, AH;Bäckvall, JE
通讯作者：
Bäckvall, JE
影响因子：
2.8
作者：
Casey, CP;Bikzhanova, GA;Kim, YH
通讯作者：
Kim, YH
影响因子：
2.8
作者：
MENASHE, N;SHVO, Y
通讯作者：
SHVO, Y
影响因子：
15
作者：
Samec, Joseph S. M.;Ell, Alida H.;Backvall, Jan-E.
通讯作者：
Backvall, Jan-E.