N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 47, Leninsky prosp., 119991 Moscow, Russian Federation.
Org Biomol Chem. 2023 Mar 1;21(9):2015-2023. doi: 10.1039/d2ob02315f.
A skeletal photorearrangement involving UV-induced 6π-electrocyclization of diarylethenes with various ethene bridges has been studied. It has been found that deprotonation is the predominant step among the three possible alternative reaction pathways (radical abstraction, deprotonation, or sigmatropic shift) following 6π-electrocyclization, and incorporation of an electronegative carbonyl group into the geminal position to the phenyl residue results in a reduction in the reaction time and an increase in the yield of the desired product. The significant increase in the reaction time in less polar solvents (toluene, TCM) also indicates a large contribution of the deprotonation step to the skeletal photorearrangement of diarylethenes. Performing the reaction in toluene in the presence of tertiary amines leads to a reduction in the reaction time and an increase in the yield of the desired product. The best results were achieved when the reaction was carried out in toluene in the presence of DIPEA. The experimental results are in good agreement with the DFT calculations.
已经研究了涉及具有各种乙烯桥的二芳基乙烯的 UV 诱导 6π-电环化的骨架光重排。已经发现，在 6π-电环化之后，脱质子是三个可能的替代反应途径（自由基提取、脱质子或 σ 迁移）中的主要步骤，并且在芳基残基的偕位引入电负性羰基会导致反应时间缩短，所需产物的产率增加。在极性较小的溶剂（甲苯、TCM）中反应时间的显著增加也表明脱质子步骤对二芳基乙烯的骨架光重排有很大的贡献。在叔胺存在下在甲苯中进行反应会导致反应时间缩短，所需产物的产率增加。当反应在存在 DIPEA 的甲苯中进行时，得到了最佳结果。实验结果与 DFT 计算吻合良好。
