Ambident Reactivity of Enolate Anions in the Gas Phase. Experimental Determination of Carbon vs Oxygen Acylation with CF<sub>3</sub>COCl
作者:Meili Zhong、John I. Brauman
DOI:10.1021/ja9502233
日期:1996.1.1
intrinsic activation energy for oxygen attack. The relative reactivity of carbon vs oxygen changes significantly with the substituent R in the enolates. The relationship between the relative overall exothermicity of the two channels and the relative reactivity of carbon vs oxygen of enolates is derived from Marcus theory. The relative overall exothermicity of the two channels is correlated with the energy
使用 FT-ICR 研究了烯醇阴离子 RCOCH2- 和 CF3COCl 之间的气相反应。碳和氧与 CF3COCl 的酰化产生不同的离子产物。对于系列 R = CF3、m-XC6H4 (X = CH3、H、OCH3、F、CF3)、H、CH3、(CH3)3C、CH2CH 和 F,观察到碳侵蚀和氧侵蚀,氧侵蚀占主导地位对于大多数烯醇。这是由于氧攻击的内在活化能较低。碳与氧的相对反应性随烯醇化物中的取代基 R 发生显着变化。两个通道的相对整体放热性与烯醇化物的碳与氧的相对反应性之间的关系源自 Marcus 理论。两个通道的相对整体放热性与能量差 ΔHke 相关,