Merging Gradient-Based Methods to Improve Benchtop NMR Spectroscopy: A New Tool for Flow Reaction Optimization
Merging Gradient-Based Methods to Improve Benchtop NMR Spectroscopy: A New Tool for Flow Reaction Optimization
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DOI：
10.1002/cphc.202000573
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发表时间：
2020-09-21
期刊：
影响因子：
2.9
通讯作者：
Farjon, Jonathan
中科院分区：
文献类型：
--
作者：
Kunjir, Shrikant;Rodriguez-Zubiri, Mireia;Farjon, Jonathan
新兴的低成本，紧凑的NMR光谱仪，可以在线连接到一个流动反应器适合于研究反应混合物。这种光谱仪的主要限制来自于它们的较低磁场，其引起降低的灵敏度和较弱的光谱分辨率。为了提高光谱分辨率，合并的纯位移方法确认线窄化与溶剂消除计划的背景下实施的混合物中含有质子化溶剂。得益于纯移脉冲序列元素之前的多个消除方案，又迈出了一步，进一步提高了紧凑型系统的分辨率。我们首次能够通过将其强度除以500至1700同时去除多达6个质子化溶剂信号，与标准1D（1）H相比，同时将感兴趣信号的光谱分辨率从9提高到12。然后，这种新的方法的潜力显示在复杂的苯并氧杂蒽酮结构的流动合成。
Emerging low cost, compact NMR spectrometers that can be connected in-line to a flow reactor are suited to study reaction mixtures. The main limitation of such spectrometers arises from their lower magnetic field inducing a reduced sensitivity and a weaker spectral resolution. For enhancing the spectral resolution, the merging of Pure-Shift methods recognized for line narrowing with solvent elimination schemes was implemented in the context of mixtures containing protonated solvents. One more step was achieved to further enhance the resolution power on compact systems, thanks to multiple elimination schemes prior to Pure-Shift pulse sequence elements. For the first time, we were able to remove up to 6 protonated solvent signals simultaneously by dividing their intensity by 500 to 1700 with a concomitant spectral resolution enhancement for signals of interest from 9 to 12 as compared to the standard 1D(1)H. Then, the potential of this new approach was shown on the flow synthesis of a complex benzoxanthenone structure.