Linear-Selective Hydroarylation of Unactivated Terminal and Internal Olefins with Trifluoromethyl-Substituted Arenes
Linear-Selective Hydroarylation of Unactivated Terminal and Internal Olefins with Trifluoromethyl-Substituted Arenes
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DOI：
10.1021/ja505579f
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发表时间：
2014-09-24
影响因子：
15
通讯作者：
Hartwig, John F.
中科院分区：
文献类型：
--
作者：
Bair, Joseph S.;Schramm, York;Hartwig, John F.
我们报道了一系列未活化烯烃与三氟甲基取代芳烃的氢芳基化反应，这些反应对芳烃上没有定向基团的线性产物具有高选择性。我们还表明，发生加氢芳基化与内部，无环烯烃，产生线性烷基芳烃产品。实验机理数据提供了证据可逆形成的烷基-镍-芳基中间体和速率决定还原消除，以形成碳-碳键。标记的研究表明，从内部烯烃的终端alkylarenes的形成发生通过初始建立的烯烃异构体的平衡混合物，然后通过添加的芳烃的终端烯烃。计算（DFT）的研究表明，芳基C-H键转移到一个配位的烯烃没有氧化加成，并支持从实验的结论，还原消除是速率决定，并形成反马尔可夫尼科夫产品。反应在α-烯烃中是逆序的;因此催化反应的发生部分是因为异构化产生低浓度的反应物α-烯烃。
We report a series of hydroarylations of unactivated olefins with trifluoromethyl-substituted arenes that occur with high selectivity for the linear product without directing groups on the arene. We also show that hydroarylations occur with internal, acyclic olefins to yield linear alkylarene products. Experimental mechanistic data provide evidence for reversible formation of an alkyl-nickel-aryl intermediate and rate-determining reductive elimination to form the carbon-carbon bond. Labeling studies show that formation of terminal alkylarenes from internal alkenes occurs by initial establishment of an equilibrating mixture of alkene isomers, followed by addition of the arene to the terminal alkene. Computational (DFT) studies imply that the aryl C-H bond transfers to a coordinated alkene without oxidative addition and support the conclusion from experiment that reductive elimination is rate-determining and forms the anti-Markovnikov product. The reactions are inverse order in alpha-olefin; thus the catalytic reaction occurs, in part, because isomerization creates a low concentration of the reactant alpha-olefin.