High-Throughput Mass Spectrometry Screening Platform for Discovering New Chemical Reactions under Uncatalyzed, Solvent-Free Experimental Conditions
High-Throughput Mass Spectrometry Screening Platform for Discovering New Chemical Reactions under Uncatalyzed, Solvent-Free Experimental Conditions
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DOI：
10.1021/acs.analchem.0c02960
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发表时间：
2020-11-17
影响因子：
7.4
通讯作者：
Badu-Tawiah, Abraham K.
中科院分区：
文献类型：
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作者：
Kulyk, Dmytro S.;Amoah, Enoch;Badu-Tawiah, Abraham K.
首次开发了气相高通量反应筛选平台，用于研究密切相关的官能团的化学结构和发现新型有机反应途径。使用包含的大气压化学电离 (APCI) 源进行实验，该源能够通过质谱 (MS) 实时监测非热、非平衡等离子体化学。这个包含 APCI MS 平台可以测试一系列试剂，从而可以并行研究多个气相反应。通过将所选试剂的顶空蒸气暴露于电晕放电，在质谱仪的高真空环境之外的气相中检查了无溶剂的 Borsche-Drecsel 环化反应、Katritzky 化学和 Paal-Knorr 吡咯合成。还发现了一种新的自由基介导的肼偶联反应，该反应提供了一种不使用催化剂合成仲胺的选择性途径。通过直接捕获中间体并与相应的本体溶液和液滴相反应进行比较，探索了这些大气压气相反应的机理。
A gas-phase high-throughput reaction screening platform was developed for the first time to study chemical structures of closely related functional groups and for the discovery of novel organic reaction pathways. Experiments were performed using the contained atmospheric pressure chemical ionization (APCI) source that enabled nonthermal, nonequilibrium plasma chemistry to be monitored by mass spectrometry (MS) in real time. This contained-APCI MS platform allowed an array of reagents to be tested, resulting in the studies of multiple gas-phase reactions in parallel. By exposing headspace vapor of the selected reagents to corona discharge, solvent-free Borsche-Drecsel cyclization reaction, Katritzky chemistry, and Paal-Knorr pyrrole synthesis were examined in the gas phase, outside the high vacuum environment of the mass spectrometer. A new radical-mediated hydrazine coupling reaction was also discovered, which provided a selective pathway to synthesize secondary amines without using a catalyst. The mechanisms of these atmospheric pressure gas-phase reactions were explored through the direct capture of intermediates and via comparison with the corresponding bulk solution and droplet-phase reactions.