13C PHIP NMR spectra and polarization transfer during the homogeneous hydrogenation of alkynes with parahydrogen
13C PHIP NMR spectra and polarization transfer during the homogeneous hydrogenation of alkynes with parahydrogen
复制标题
炔烃与仲氢均相加氢过程中的 13C PHIP NMR 谱和偏振转移
DOI：
10.1002/mrc.973
复制
发表时间：
2002
影响因子：
2
通讯作者：
J. Bargon
中科院分区：
文献类型：
--
作者：
M. Stephan;O. Kohlmann;H. Niessen;A. Eichhorn;J. Bargon
仲氢均相催化氢化不饱和底物不仅在~ 1H NMR谱中产生强极化信号，而且在低磁场下氢化反应也能产生强的异相极化。作为一个典型的例子，从质子到碳原子核的极化转移过程中的炔氢化概述了几个基板。在含有容易接近的三键的体系中，例如苯基乙炔或3，3-二甲基-1-丁炔，分子中的所有碳核都发生极化转移。因此，在原位记录的NMR光谱中，仅使用单个瞬态就可以观察到具有良好至优异信噪比的所有13 C共振。定性的对称性和电子方面的基板和其氢化产物的极化转移到13 C-核的效率的影响进行了讨论。版权所有© 2001约翰威利父子有限公司
Homogeneously catalyzed hydrogenations of unsaturated substrates with parahydrogen not only lead to strong polarization signals in 1H NMR spectra, but also can give rise to strong heteronuclear polarization, especially if the hydrogenations are carried out in low magnetic fields. As a typical example, the polarization transfer from protons to carbon nuclei during the hydrogenation of alkynes is outlined for several substrates. In systems containing easily accessible triple bonds, e.g. phenylethyne or 3,3‐dimethyl‐1‐butyne, polarization transfer occurs to all carbon nuclei in the molecule. Accordingly, in NMR spectra recorded in situ all 13C resonances can be observed with good to excellent signal‐to‐noise ratios using only a single transient. The qualitative influence of symmetry and electronic aspects of the substrate and its hydrogenation product on the efficiency of the transfer of polarization to the 13C‐nuclei are discussed. Copyright © 2001 John Wiley & Sons, Ltd.