Parchomyk Tobias, Koszinowski Konrad
Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077, Göttingen, Germany.
Chemistry. 2017 Mar 2;23(13):3213-3219. doi: 10.1002/chem.201605602. Epub 2017 Feb 1.
The cluster ion Me Fe is an unprecedented representative of organoiron species, which are of great interest because of their possible role as intermediates in iron-catalyzed cross-coupling reactions. To learn more about its behavior in solution, the possible formation of related cluster ions, and their reactivity, electrospray-ionization mass spectrometry and gas-phase experiments were performed. Me Fe adopts a highly dynamic behavior in solution and disappears in the presence of the chelating ligand N,N,N',N'-tetramethylethylenediamine. Besides homoleptic Me Fe , its heteroleptic analogues Me Fe Ph , n=1-5, are also accessible. Me Fe undergoes iron-halogen exchange reactions with aryl halides. These substrates, as well as their alkyl counterparts, mediate the formation of new homoleptic cluster ions up to Me Fe . In contrast, no evidence was found for oxidative additions or related reactions. Gas-phase fragmentation of the cluster ions results in numerous different reactions, ranging from the loss of single methyl radicals to the reductive elimination of MePh.
簇离子Me₄Fe是有机铁物种中前所未有的代表，由于它们可能作为铁催化交叉偶联反应的中间体而备受关注。为了更多地了解其在溶液中的行为、相关簇离子的可能形成及其反应性，进行了电喷雾电离质谱和气相实验。Me₄Fe在溶液中表现出高度动态的行为，并且在螯合配体N,N,N',N'-四甲基乙二胺存在下会消失。除了同配体的Me₄Fe，其异配体类似物Me₄₋ₙFePhₙ，n = 1 - 5，也可以得到。Me₄Fe与芳基卤化物发生铁-卤素交换反应。这些底物以及它们的烷基对应物介导了新的同配体簇离子直至Me₈Fe的形成。相比之下，没有发现氧化加成或相关反应的证据。簇离子的气相碎片化导致许多不同的反应，从单个甲基自由基的损失到MePh的还原消除。
