Hydrophosphination of Styrene and Polymerization of Vinylpyridine: A Computational Investigation of Calcium-Catalyzed Reactions and the Role of Fluxional Noncovalent Interactions
Hydrophosphination of Styrene and Polymerization of Vinylpyridine: A Computational Investigation of Calcium-Catalyzed Reactions and the Role of Fluxional Noncovalent Interactions
复制标题
DOI：
10.1021/acscatal.6b02251
复制
发表时间：
2017-01
期刊：
影响因子：
12.9
通讯作者：
B. Ward;P. Hunt
中科院分区：
文献类型：
--
作者：
B. Ward;P. Hunt
提出了由杂配 β-二酮亚胺稳定钙络合物 [(PhNC(Me)CHC(Me)NPh)CaPPh2] 催化的苯乙烯和 2-乙烯基吡啶分子间氢膦酸化的计算研究。烯烃插入并不按照与碱土金属或镧系元素络合物催化的分子间氢胺化相关的实验和理论研究提出的传统路线进行。相反，对于氢膦化机制，插入是通过外球、共轭加成进行的，其中 Ca 与乙烯基官能团没有直接相互作用。在初始决定速率的烯烃插入之后，出现了两种不同的机制：质子分解或聚合。苯乙烯的聚合在能量上不如质子分解有利，而 2-乙烯基吡啶则相反，从而为实验观察到的结果提供了强有力的证据。乙烯基芳烃环很重要，因为它允许不饱和的优先配位...
A computational investigation of the intermolecular hydrophosphination of styrene and 2-vinylpyridine, catalyzed by the heteroleptic β-diketiminato-stabilized calcium complex [(PhNC(Me)CHC(Me)NPh)CaPPh2], is presented. Alkene insertion does not proceed via the traditional route as proposed by experimental and theoretical research related to intermolecular hydroamination catalyzed by alkaline earth or lanthanide complexes. In contrast, for the hydrophosphination mechanism, insertion proceeds via outer sphere, conjugative addition where there is no direct interaction of Ca with the vinyl functionality. Following the initial rate-determining alkene insertion, two distinct mechanisms emerge, protonolysis or polymerization. Polymerization of styrene is energetically less favorable than protonolysis, whereas the reverse is determined for 2-vinylpyridine, thereby providing strong evidence of outcomes observed experimentally. The vinylarene ring is important as it allows for preferential coordination of the unsat...