Stratingh Institute for Chemistry, University of Groningen , Nijenborgh 4, 9747 Groningen, AG, The Netherlands.
J Org Chem. 2017 May 19;82(10):5027-5033. doi: 10.1021/acs.joc.7b00852. Epub 2017 May 1.
The enantiomeric homogeneity of light-driven molecular motors based on overcrowded alkenes is crucial in their application as either unidirectional rotors or as chiral multistate switches. It was challenging to obtain these compounds as single enantiomers via the established synthetic procedures due to loss of optical purity in the key step, i.e., the Barton-Kellogg olefination reaction. Searching for strategies to avoid racemization, a new class of light-driven molecular motors was designed, synthesized, and studied. The stereochemical integrity was fully preserved throughout the synthesis, and on the basis of photochemical and kinetic studies using UV/vis, CD, and H NMR spectroscopy, it was established that they still function properly as unidirectional molecular motors.
基于过度拥挤烯烃的光驱动分子马达的对映体均一性对于它们作为单向转子或手性多态开关的应用至关重要。由于关键步骤（即 Barton-Kellogg 烯烃化反应）中光学纯度的损失，通过既定的合成程序获得这些化合物的单一对映异构体具有挑战性。为了寻找避免外消旋化的策略，设计、合成和研究了一类新的光驱动分子马达。整个合成过程中立体化学完整性得到了完全保留，并且基于使用 UV/vis、CD 和 H NMR 光谱的光化学和动力学研究，确定它们仍然可以作为单向分子马达正常发挥作用。
