日本北海道大学Katsuyama, Akira团队报道了硫族元素取代实现含氮体系的光致双键旋转。相关研究成果发表在2024年2月28日出版的《自然—化学》。

在一些生物系统中已经提出了光诱导的协同多键旋转。然而，在合成系统中观察这种现象，换言之，合成在光照射下经历光诱导多键旋转的分子，在光化学领域是一个挑战。

该文中，研究人员描述了一种硫族取代的苯甲酰胺体系，该体系在含杂原子的键中表现出光诱导的双键旋转。将硫族取代基引入空间位阻的苯甲酰胺体系提供了足够的动力学稳定性和光敏性，以实现光诱导的协同旋转。硫酰胺衍生物的苯环上存在两个不同的取代基，这使得能够产生一对对映异构体和E/Z异构体。使用这四种立体异构体作为键旋转的指标，研究人员监测了硫酰胺衍生物中取决于外部刺激，如温度和光照的光诱导C–N/C–C协同键旋转。

理论计算为这种选择性光诱导的C–N/C–C协同旋转的机制提供了见解。

附：英文原文

Title: Photoinduced dual bond rotation of a nitrogen-containing system realized by chalcogen substitution

Author: Nagami, Shotaro, Kaguchi, Rintaro, Akahane, Taichi, Harabuchi, Yu, Taniguchi, Tohru, Monde, Kenji, Maeda, Satoshi, Ichikawa, Satoshi, Katsuyama, Akira

Issue&Volume: 2024-02-28

Abstract: Photoinduced concerted multiple-bond rotation has been proposed in some biological systems. However, the observation of such phenomena in synthetic systems, in other words, the synthesis of molecules that undergo photoinduced multiple-bond rotation upon photoirradiation, has been a challenge in the photochemistry field. Here we describe a chalcogen-substituted benzamide system that exhibits photoinduced dual bond rotation in heteroatom-containing bonds. Introduction of the chalcogen substituent into a sterically hindered benzamide system provides sufficient kinetic stability and photosensitivity to enable the photoinduced concerted rotation. The presence of two different substituents on the phenyl ring in the thioamide derivative enables the generation of a pair of enantiomers and E/Z isomers. Using these four stereoisomers as indicators of which bonds are rotated, we monitor the photoinduced C–N/C–C concerted bond rotation in the thioamide derivative depending on external stimuli such as temperature and photoirradiation. Theoretical calculations provide insight on the mechanism of this selective photoinduced C–N/C–C concerted rotation.

DOI: 10.1038/s41557-024-01461-9

Source: https://www.nature.com/articles/s41557-024-01461-9