Synergistic Bimetallic Ni/Ag and Ni/Cu Catalysis for Regioselective γ,δ-Diarylation of Alkenyl Ketimines: Addressing β-H Elimination by in Situ Generation of Cationic Ni(II) Catalysts
Synergistic Bimetallic Ni/Ag and Ni/Cu Catalysis for Regioselective γ,δ-Diarylation of Alkenyl Ketimines: Addressing β-H Elimination by in Situ Generation of Cationic Ni(II) Catalysts
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DOI：
10.1021/jacs.8b09401
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发表时间：
2018-11-21
影响因子：
15
通讯作者：
Giri, Ramesh
中科院分区：
文献类型：
--
作者：
Basnet, Prakash;Shekhar, K. C.;Giri, Ramesh
我们公开了一种前所未有的协同双金属催化剂，用于简单酮胺中未活化的烯烃与芳基卤化物和芳基锌试剂的区域选择性芳香化反应。双金属协同作用在反应过程中产生阳离子Ni(II)物种，促进了迁移插入和转金属步骤，抑制了β-H消除和交叉偶联，这是在烯烃双官能化过程中导致严重问题的主要副反应。这种二芳基化反应在遥远的位置进行，亚胺经过简单的H+处理后，可以得到不同取代的伽马、三角洲-二芳基酮，否则很难用现有方法容易地获得这些化合物。
We disclose unprecedented synergistic bimetallic Ni/Ag and Ni/Cu catalysts for regioselective ykdiarylation of unactivated alkenes in simple ketimines with aryl halides and arylzinc reagents. The bimetallic synergy, which generates cationic Ni(II) species during reaction, promotes migratory insertion and transmetalation steps and suppresses beta-H elimination and cross coupling, the major side reactions that cause serious problems during alkene difunctionalization. This diarylation reaction proceeds at remote locations to imines to afford, after simple H+ workup, diversely substituted gamma,delta-diaryl ketones that are otherwise difficult to access readily with existing methods.