Competitive C-I versus C-CN reductive elimination from a Rh(III) complex. Selectivity is controlled by the solvent.
Competitive C-I versus C-CN reductive elimination from a Rh(III) complex. Selectivity is controlled by the solvent.
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Rh(III) 络合物中 C-I 与 C-CN 的竞争性还原消除。
DOI：
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发表时间：
2008
影响因子：
15
通讯作者：
D. Milstein
中科院分区：
文献类型：
--
作者：
Moran Feller;M. Iron;L. Shimon;Y. Diskin‐Posner;G. Leitus;D. Milstein
RhIII络合物[（PNP）Rh（CN）（CH 3）][I] 5，通过碘甲烷与[（PNP）Rh（CN）] 2的氧化加成获得，在两种途径中选择性反应：在非质子溶剂中，碘甲烷发生C-I还原消除，然后亲电攻击氰基配体，得到甲基异腈RhI络合物[（PNP）Rh（CNCH 3）][I] 3，而在质子溶剂中，发生乙腈的C-C还原消除，形成碘化RhI络合物[（PNP）RhI] 9。2与碘乙烷在非质子溶剂中反应得到相应的异腈配合物，而在质子溶剂中没有观察到反应性。该反应的选择性可能是由于氰基配体和质子溶剂之间的氢键，如通过X-射线衍射观察到的，其阻碍了对该配体的亲电攻击。
The RhIII complex [(PNP)Rh(CN)(CH3)][I] 5, obtained by oxidative addition of methyl iodide to [(PNP)Rh(CN)] 2, reacts selectively in two pathways: In aprotic solvents C-I reductive elimination of methyl iodide followed by its electrophilic attack on the cyano ligand takes place, giving the methyl isonitrile RhI complex [(PNP)Rh(CNCH3)][I] 3, while in protic solvents C-C reductive elimination of acetonitrile takes place forming an iodo RhI complex [(PNP)RhI] 9. Reaction of 2 with ethyl iodide in aprotic solvents gave the corresponding isonitrile complex, while in protic solvents no reactivity was observed. The selectivity of this reaction is likely due to a hydrogen bond between the cyano ligand and the protic solvent, as observed by X-ray diffraction, which retards electrophilic attack on this ligand.