Diastereotopic fluorine substituents as 19F NMR probes of screw-sense preference in helical foldamers.
Diastereotopic fluorine substituents as 19F NMR probes of screw-sense preference in helical foldamers.
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DOI：
10.1039/c3ob40463c
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发表时间：
2013-04
影响因子：
3.2
通讯作者：
Sarah J. Pike;M. De Poli;Wojciech Zawodny;J. Raftery;S. J. Webb;J. Clayden
中科院分区：
文献类型：
--
作者：
Sarah J. Pike;M. De Poli;Wojciech Zawodny;J. Raftery;S. J. Webb;J. Clayden
将含有对映体氟取代基的简单氨基醇或氨基酯单体连接到螺旋肽的C-末端，将氟原子置于非对映体环境中，并在（19）F NMR光谱中给出两个不同且容易识别的信号。在由非手性单体构建的动态反转螺旋的情况下，（19）F信号之间的化学位移分离提供了一种简单的方法来分析低聚物中螺旋正义构象异构体的比例，在不对称偏置导致螺旋正义偏好的情况下。
Ligating simple amino alcohol or amino ester monomers containing enantiotopic fluorine substituents to the C-terminus of a helical peptide places the fluorine atoms in diastereotopic environments, and gives two distinct and easily identifiable signals in the (19)F NMR spectrum. In the case of a dynamically inverting helix built from achiral monomers, the chemical shift separation between the (19)F signals provides a simple means of analysing the ratio of screw-sense conformers in the oligomer, in cases where an asymmetric bias leads to a screw-sense preference.