Non-Precious Metal Catalysts for C-H Borylation Enabled by Metal-Metal Cooperativity
Non-Precious Metal Catalysts for C-H Borylation Enabled by Metal-Metal Cooperativity
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DOI：
10.1055/s-0033-1340823
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发表时间：
2014-06-01
期刊：
影响因子：
2
通讯作者：
Mankad, Neal P.
中科院分区：
文献类型：
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作者：
Mankad, Neal P.
用于C-H官能化的均相催化剂通常需要贵金属，例如Pd、Ru、Rh或Ir，因为它们易于介导两电子氧化还原机制。贱金属如Cu或Fe反而倾向于经历单电子氧化还原过程。通过将两个贱金属位点偶联在一起，发现了用于光化学C-H硼基化的贱金属催化剂。最佳催化剂（IPr）Cu-FeCp（CO）（2）代表了第一种不含贵金属的C-H硼基化均相催化剂。以这种方式使用金属-金属协同性允许贱金属催化剂代替贵金属催化剂，同时保持有利的区域选择性模式。所提出的杂环C-H硼基化机制的特点是经典的有机金属反应步骤的简化版本，作为未来催化剂设计的指导，并打开了其他贵金属转化的可能性，使用金属-金属协同效应作为设计策略。
Homogeneous catalysts for C-H functionalization typically require precious metals such as Pd, Ru, Rh, or Ir because of their facility in mediating two-electron redox mechanisms. Base metals such as Cu or Fe instead tend to undergo one-electron redox processes. By coupling together two base metal sites in a heterobimetallic catalyst design, base metal catalysts for photochemical C-H borylation were discovered. The optimal catalyst, (IPr)Cu-FeCp(CO)(2), represents the first homogeneous catalyst for C-H borylation that contains no precious metals. Using metal-metal cooperativity in this way allows for base metal catalysts to replace precious metal catalysts while maintaining advantageous regioselectivity patterns. The proposed mechanism for heterobimetallic C-H borylation features bimetallic versions of classic organometallic reaction steps, serves as a guide for future catalyst designs, and opens the possibility for other precious metal transformations to be approached using metal-metal cooperativity as a design strategy.