Structure-reactivity correlations for reactions of substituted phenolate anions with acetate and formate esters
作者:Dimitrios Stefanidis、Sayeon Cho、Sirano Dhe-Paganon、William P. Jencks
DOI:10.1021/ja00058a006
日期:1993.3
substituted phenolate anions with m-nitrophenyl, p-nitrophenyl, and 3,4-dinitrophenyl formates follow nonlinear BrOnsted-type correlations that might be taken as evidence for a change in the rate-limiting step of a reaction that proceeds through a tetrahedral addition intermediate. However, the correlation actually represents two different BrOnsted lines that are defined by meta- and para-substituted phenolate
取代苯酚阴离子与间硝基苯基、对硝基苯基和 3,4-二硝基苯基甲酸酯的反应遵循非线性 BrOnsted 型相关性,可以作为反应的限速步骤发生变化的证据。四面体加成中间体。然而,相关性实际上代表了两个不同的布朗斯特线,它们由间位和对位取代的苯酚阴离子以及间位和对位取代的邻氯苯酚阴离子定义。在 ΔpK=0 时,在每一类 BrOnsted 相关性中攻击和离开酚酸阴离子的 BrOnsted 斜率没有可检测的变化,这支持了乙酰基和甲酰基转移反应的协调机制