Selective Nuclear Magnetic Resonance Experiments for Sign-Sensitive Determination of Heteronuclear Couplings: Expanding the Analysis of Crude Reaction Mixtures
作者:Guilherme Dal Poggetto、João Vitor Soares、Cláudio F. Tormena
DOI:10.1021/acs.analchem.0c02976
日期:2020.10.20
State-of-the-art nuclear magnetic resonance (NMR) selective experiments are capable of directly analyzing crude reaction mixtures. A new experiment named HD-HAPPY-FESTA yields ultrahigh-resolution total correlation subspectra, which are suitable for sign-sensitive determination of heteronuclear couplings, as demonstrated here by measuring the sign and magnitude for proton–fluorine couplings (JHF) from
最先进的核磁共振(NMR)选择性实验能够直接分析粗制反应混合物。一项名为HD-HAPPY-FESTA的新实验可产生超高分辨率的全相关子谱,适用于杂核耦合的符号灵敏测定,如本文中通过测量主要原子和氢原子质子-氟偶合(J HF)的符号和强度所证明。两步反应的少量异构体产物,无需任何纯化。可以使用HD-HAPPY-FESTA测量51.5至-2.6 Hz范围内的质子-氟偶联,最小测量幅度为0.8 Hz。实验J HF值用于鉴定两种氟代酮中间体和四种氟代醇产物。将结果合理化,并与密度泛函理论(DFT)计算进行比较。将实验数据与文献中报道的耦合进行了比较,其中对纯样品进行了分析。