Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371.
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States.
J Am Chem Soc. 2020 Jul 1;142(26):11521-11527. doi: 10.1021/jacs.0c04144. Epub 2020 Jun 19.
Here we design an interface between a metal nanoparticle (NP) and a metal-organic framework (MOF) to activate an inert CO carboxylation reaction and in situ monitor its unconventional regioselectivity at the molecular level. Using a Kolbe-Schmitt reaction as model, our strategy exploits the NP@MOF interface to create a pseudo high-pressure CO microenvironment over the phenolic substrate to drive its direct C-H carboxylation at ambient conditions. Conversely, Kolbe-Schmitt reactions usually demand high reaction temperature (>125 °C) and pressure (>80 atm). Notably, we observe an unprecedented CO meta-carboxylation of an arene that was previously deemed impossible in traditional Kolbe-Schmitt reactions. While the phenolic substrate in this study is fixed at the NP@MOF interface to facilitate spectroscopic investigations, free reactants could be activated the same way by the local pressurized CO microenvironment. These valuable insights create enormous opportunities in diverse applications including synthetic chemistry, gas valorization, and greenhouse gas remediation.
在这里，我们设计了一种金属纳米粒子（NP）和金属有机骨架（MOF）之间的界面，以激活惰性 CO 羧化反应，并在分子水平上原位监测其非传统的区域选择性。我们的策略利用 NP@MOF 界面来创造一个赝高气压 CO 微环境，以驱动酚类底物在环境条件下直接进行 C-H 羧化反应，这一反应以 Kolbe-Schmitt 反应作为模型。相反，Kolbe-Schmitt 反应通常需要高温 (>125°C) 和高压 (>80atm)。值得注意的是，我们观察到一种前所未有的芳烃的 CO 间位羧化反应，这在传统的 Kolbe-Schmitt 反应中是不可能的。虽然在这项研究中，酚类底物被固定在 NP@MOF 界面上，以促进光谱学研究，但游离反应物也可以通过局部加压的 CO 微环境以同样的方式被激活。这些有价值的见解为包括合成化学、气体增值和温室气体修复在内的各种应用创造了巨大的机会。
