作者:Philip Dell‘Orco、Jeffrey Brum、Richard Matsuoka、Manish Badlani、Kenneth Muske
DOI:10.1021/ac990554o
日期:1999.11.1
We present results using an unmodified nebulized assisted electrospray ionization (ESI) interface to observe a process-scale organic reaction (26 wt % in reactants) in real time. The approach offers distinct advantages over optical methods because unambiguous MW information can be obtained. The approach uses a series of pumps, which, after sampling the reactor, (1) quench the reaction, (2) reduce the concentration (3000×), and (3) add a proton-donating buffer for ionization. The approach is demonstrated with a piperidine-catalyzed Knoevenagel condensation reaction in toluene with informative results. The particular softness of ESI affords the formation of protonated parent ions almost exclusively. Reactions are tracked following [M + H]+ ion signatures as a function of time. In addition to providing information about kinetic rates, mechanistic information was obtained via the observation of the Mannich base intermediate of the reaction. Use of the data in regard to absolute ion intensities as well as future applications are discussed.
我们使用未修改的雾化辅助电喷雾电离 (ESI) 接口实时观察过程规模的有机反应(反应物中 26 wt%)来展示结果。该方法比光学方法具有明显的优势,因为可以获得明确的分子量信息。该方法使用一系列泵,在对反应器取样后,(1) 淬灭反应,(2) 降低浓度 (3000×),(3) 添加供质子缓冲液用于电离。该方法通过哌啶催化的甲苯中的 Knoevenagel 缩合反应得到证明,并获得了丰富的结果。 ESI 的特殊柔软性几乎可以完全形成质子化母离子。根据 [M + H]+ 离子特征作为时间函数跟踪反应。除了提供有关动力学速率的信息外,还通过观察反应的曼尼希碱中间体获得了机理信息。讨论了有关绝对离子强度的数据的使用以及未来的应用。