APICOPHILICITY AND RING-STRAIN IN FIVE-COORDINATE PHOSPHORANES
APICOPHILICITY AND RING-STRAIN IN FIVE-COORDINATE PHOSPHORANES
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DOI：
10.1080/03086647608070718
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发表时间：
1976-08
影响因子：
1.3
通讯作者：
S. Trippett
中科院分区：
文献类型：
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作者：
S. Trippett
为了探讨有机磷化学中的反应机理，必须作一些假设。其中包括：（a）在四面体磷上的取代通过五配位中间体进行;（B）这些中间体是三角双锥的;（c）它们通过顶端进攻形成，并通过顶端损失分解;（d）如果足够长的寿命，它们可能经历置换异构化，即配体可能在继续生成产物或返回反应物之前改变它们围绕磷的相对配置。假设一个给定的取代过程主要由热力学因素决定，为了理解该取代过程，需要知道如何评估四种异构体tbps的相对稳定性。（三角双锥），可以形成最初和其他可能形成的后续异构化，这些异构化的障碍，以及各种产品形成步骤的相对速率。我们有浓度…
Abstract In order to dicuss mechanism in organophosphorus chemistry a number of assumptions have to be made. Among them are: (a) that substitutions at tetrahedral phosphorus proceed via five-coordinate intermediates; (b) these intermediates are trigonal bipyramidal; (c) they are formed by apical attack and decompose by apical loss; and (d) if sufficiently long-lived, they may undergo permutational isomerization, that is the ligands may alter their relative dispositions round the phosphorus, before going on to products or back to reactants. Assuming that the course of a given substitution is dictated primarily by thermodynamic considerations, in order to understand the course of that substitution one needs to know how to assess the relative stabilities of the four isomeric tbps (trigonal bipyramids) that can be formed initially and of the others that could be formed by subsequent isomerization, the barriers to those isomerizations, and the relative rates of the various product-forming steps. We have concen...