Guo Yongjie, Lian Xueqi, Zhang Hao, Zhang Xueling, Chen Jun, Chen Changzhong, Lan Xiaobing, Shao Youxiang
Hunan Provincial Key Laboratory of Xiangnan Rare-Precious Metals Compounds Research and Application, School of Chemistry and Environmental Science, Xiangnan University, Chenzhou 423000, China.
Key Laboratory of Electronic Functional Materials and Devices of Guangdong Province, School of Chemistry and Materials Engineering, Huizhou University, Huizhou 516007, China.
Molecules. 2023 Dec 19;29(1):24. doi: 10.3390/molecules29010024.
Unreactive C-H bond activation is a new horizon for frustrated Lewis pair (FLP) chemistry. This study provides a systematic assessment of the catalytic reactivity of recently reported intra-molecular FLPs on the activation of typical inert C-H bonds, including 1-methylpyrrole, methane, benzyl, propylene, and benzene, in terms of density functional theory (DFT) calculations. The reactivity of FLPs is evaluated according to the calculated reaction thermodynamic and energy barriers of C-H bond activation processes in the framework of concerted C-H activation mechanisms. As for 1-methylpyrrole, 14 types of N-B-based and 15 types of P-B-based FLPs are proposed to be active. Although none of the evaluated FLPs are able to catalyze the C-H activation of methane, benzyl, or propylene, four types of N-B-based FLPs are suggested to be capable of catalyzing the activation of benzene. Moreover, the influence of the strength of Lewis acid (LA) and Lewis base (LB), and the differences between the influences of LA and LB on the catalytic reactivity of FLPs, are also discussed briefly. This systematic assessment of the catalytic activity of FLPs should provide valuable guidelines to aid the development of efficient FLP-based metal-free catalysts for C-H bond activation.
非活性C-H键活化是受阻路易斯酸碱对（FLP）化学的一个新领域。本研究基于密度泛函理论（DFT）计算，对最近报道的分子内FLP在典型惰性C-H键（包括1-甲基吡咯、甲烷、苄基、丙烯和苯）活化方面的催化反应活性进行了系统评估。在协同C-H活化机制框架内，根据计算得到的C-H键活化过程的反应热力学和能垒来评估FLP的反应活性。对于1-甲基吡咯，提出了14种基于N-B的FLP和15种基于P-B的FLP具有活性。尽管所评估的FLP均不能催化甲烷、苄基或丙烯的C-H活化，但有四种基于N-B的FLP被认为能够催化苯的活化。此外，还简要讨论了路易斯酸（LA）和路易斯碱（LB）强度的影响，以及LA和LB对FLP催化反应活性影响的差异。这种对FLP催化活性的系统评估应为开发高效的基于FLP的无金属C-H键活化催化剂提供有价值的指导。
