Noncovalent Interactions Drive the Efficiency of Molybdenum Imido Alkylidene Catalysts for Olefin Metathesis
Noncovalent Interactions Drive the Efficiency of Molybdenum Imido Alkylidene Catalysts for Olefin Metathesis
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DOI：
10.1021/jacs.9b04367
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发表时间：
2019-07-10
影响因子：
15
通讯作者：
Coperet, Christophe
中科院分区：
文献类型：
--
作者：
Ferreira, Marco A. B.;Silva, Jordan De Jesus;Coperet, Christophe
高通量实验和多变量建模可以识别原位制备的单芳氧基-吡咯烷酰亚氨基亚烷基复分解催化剂中的非共价相互作用 (NCI)，作为代表性复分解反应（1-壬烯的同二聚）中高活性的关键驱动因素。统计单变量和多变量模型将 35 种酚配体的催化数据分为两组，具体取决于酚配体邻位的取代。当苯酚带有邻位芳基取代基时，催化活性描述符 TON1h 主要与吸引性 NCI 相关，反之，当苯酚没有芳基邻位取代基时，催化活性描述符 TON1h 主要与排斥性 NCI 相关。采用能量跨度分析将观察到的 NCI 和环化复分解步骤联系起来，使得没有邻芳基的芳氧基配体主要影响金属环丁烷中间体（SP/TBP 异构体）的能量，而具有侧挂邻芳基的芳氧基化物影响环化步骤的过渡态能量。虽然芳氧基配体的电子效应也发挥了作用，但我们的工作概述了如何利用 NCI 来设计改进的 d(0) 复分解催化剂。
High-throughput experimentation and multivariate modeling allow identification of noncovalent interactions (NCIs) in monoaryloxy-pyrrolide Mo imido alkylidene metathesis catalysts prepared in situ as a key driver for high activity in a representative metathesis reaction (homodimerization of 1-nonene). Statistical univariate and multivariate modeling categorizes catalytic data from 35 phenolic ligands into two groups, depending on the substitution in the ortho position of the phenol ligand. The catalytic activity descriptor TON1h correlates predominantly with attractive NCIs when phenols bear ortho aryl substituents and, conversely, with repulsive NCIs when the phenol has no aryl ortho substituents. Energetic span analysis is deployed to relate the observed NCI and the cycloreversion metathesis step such that aryloxide ligands with no ortho aryls mainly impact the energy of metallacyclobutane intermediates (SP/TBP isomers), whereas aryloxides with pendant ortho aryls influence the transition state energy for the cycloreversion step. While the electronic effects from the aryloxide ligands also play a role, our work outlines how NCIs may be exploited for the design of improved d(0) metathesis catalysts.