大连理工大学段春迎团队报道了一种金属有机框架作为惰性碳(sp3)氢键活化和氧化的多光子激发调节剂。相关研究成果于2021年11月7日发表在《德国应用化学》。

惰性C（sp3）-H键的活化和氧化为增值化学品提供了诱人的经济和生态效益，同时也是现代化学的核心挑战。

受自然酶转化的启发，研究人员在该文中报告了一种新的多光子激发方法，通过将光诱导电子转移（PET）、配体到金属电荷转移（LMCT）和氢原子转移（HAT）事件整合到一个金属-有机框架中来激活惰性C（sp3）-H键和氧化。经过良好修饰的烟酰胺腺嘌呤二核苷酸（NAD+）模拟氧化的CeIIIOEt部分生成CeIVOEt生色团，其还原态通过PET模拟NAD。原位形成的CeIVOEt部分触发LMCT激发形成烷氧基EtO，从C（sp3）-H键中提取氢原子，伴随CeIVOEt的恢复和烷基自由基的形成。

形成的NAD活化氧以再生NAD+，用于下一次循环，其中，活化氧物种与用于氧化功能化的中间体相互作用，为开发可扩展和可持续的合成策略铺平了催化途径。

附：英文原文

Title: A Metal−Organic Framework as a Multiphoton Excitation Regulator for the Activation of Inert C(sp3)−H Bonds and Oxygen

Author: Guanfeng Ji, Liang Zhao, Jianwei Wei, Junkai Cai, Cheng He, Zenggang Du, Wei Cai, Chunying Duan

Issue&Volume: 2021-11-07

Abstract: The activation and oxidization of inert C(sp3)H bonds into value-added chemicals affords attractively economic and ecological benefits as well as central challenge in modern chemistry. Inspired by the natural enzymatic transformation, herein, we report a new multiphoton excitation approach to activate the inert C(sp3)H bonds and oxygen by integrating the photoinduced electron transfer (PET), ligand-to-metal charge transfer (LMCT) and hydrogen atom transfer (HAT) events together into one metal–organic framework. The well-modified nicotinamide adenine dinucleotide (NAD+) mimics oxidized CeIIIOEt moieties to generate CeIVOEt chromophore and its reduced state mimics NAD via PET. The in situ formed CeIVOEt moiety triggers a LMCT excitation to form the alkoxy radical EtO, abstracts a hydrogen atom from the C(sp3)H bond, accompanying the recovery of CeIIIOEt and the formation of alkyl radicals. The formed NAD activates oxygen to regenerate the NAD+ for next recycle, wherein, the activated oxygen species interacts with the intermediates for the oxidization functionalization, paving a catalytic avenue for developing scalable and sustainable synthetic strategy.

DOI: 10.1002/anie.202114490

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202114490