Diastereoselective [3+2] Annulation of Aromatic/Vinylic Amides with Bicyclic Alkenes through Cobalt-Catalyzed C-H Activation and Intramolecular Nucleophilic Addition
Diastereoselective [3+2] Annulation of Aromatic/Vinylic Amides with Bicyclic Alkenes through Cobalt-Catalyzed C-H Activation and Intramolecular Nucleophilic Addition
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DOI：
10.1002/anie.201512018
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发表时间：
2016-03-18
影响因子：
16.6
通讯作者：
Cheng, Chien-Hong
中科院分区：
文献类型：
--
作者：
Gandeepan, Parthasarathy;Rajamalli, Pachaiyappan;Cheng, Chien-Hong
介绍了一种由芳香族/乙烯基酰胺和双环烯合成二氢环氧基苯并荧酮衍生物的高度非对映选择性方法。这种新的转化通过钴催化的C-H活化和分子内的亲核加成反应进行到酰胺官能团。过渡金属催化的仲酰胺与烯烃的C-H活化反应通常导致[4+2]或[4+1]环化；据我们所知，这是首次在这种情况下描述[3+2]环加成反应。反应在温和的条件下进行，并能容忍广泛的官能团。机理研究表明，C-H键断裂可能是限速步骤。
A highly diastereoselective method for the synthesis of dihydroepoxybenzofluorenone derivatives from aromatic/vinylic amides and bicyclic alkenes is described. This new transformation proceeds through cobalt-catalyzed C-H activation and intramolecular nucleophilic addition to the amide functional group. Transition-metal-catalyzed C-H activation reactions of secondary amides with alkenes usually lead to [4+2] or [4+1] annulation; to the best of our knowledge, this is the first time that a [3+2] cycloaddition is described in this context. The reaction proceeds under mild conditions and tolerates a wide range of functional groups. Mechanistic studies imply that the C-H bond cleavage may be the rate-limiting step.