Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, Beijing, People's Republic of China.
Environment Research Institute, Shandong University, Qingdao, People's Republic of China.
Nat Chem. 2023 Jul;15(7):972-979. doi: 10.1038/s41557-023-01212-2. Epub 2023 May 15.
Stereochemistry has an essential role in organic synthesis, biological catalysis and physical processes. In situ chirality identification and asymmetric synthesis are non-trivial tasks, especially for single-molecule systems. However, going beyond the chiral characterization of a large number of molecules (which inevitably leads to ensemble averaging) is crucial for elucidating the different properties induced by the chiral nature of the molecules. Here we report direct monitoring of chirality variations during a Michael addition followed by proton transfer and keto-enol tautomerism in a single molecule. Taking advantage of the chirality-induced spin selectivity effect, continuous current measurements through a single-molecule junction revealed in situ chirality variations during the reaction. Chirality identification at a high sensitivity level provides a promising tool for the study of symmetry-breaking reactions and sheds light on the origin of the chirality-induced spin selectivity effect itself.
立体化学在有机合成、生物催化和物理过程中起着至关重要的作用。在原位手性识别和不对称合成方面，这是一项具有挑战性的任务，特别是对于单分子体系而言。然而，要阐明分子手性所引起的不同性质，超越大量分子的手性特征（这不可避免地导致了平均化）是至关重要的。在这里，我们报告了在单个分子中迈克尔加成反应、质子转移和酮-烯醇互变异构反应过程中手性变化的直接监测。利用手性诱导的自旋选择性效应，通过单分子结进行的连续电流测量揭示了反应过程中手性的变化。在高灵敏度水平上对手性的识别为研究对称破缺反应提供了一个很有前途的工具，并阐明了手性诱导的自旋选择性效应本身的起源。
