Fisher Sergey, Huang Hsin-Hua, Sokoliuk Luise, Prescimone Alessandro, Fuhr Olaf, Šolomek Tomáš
Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, XH Amsterdam NL-1098, the Netherlands.
Department of Chemistry, University of Basel, St. Johanns-Ring 19, Basel CH-4056, Switzerland.
J Org Chem. 2025 Mar 28;90(12):4158-4166. doi: 10.1021/acs.joc.4c02547. Epub 2025 Mar 17.
Formation of imine organic cages relies on the error correction of dynamic covalent chemistry. Here, we demonstrate kinetically trapped rylene diimide [2 + 3] cages formed in high yields, and we investigate the effect of substituents on their formation kinetics and stability. Thereby, we identified that alkoxy groups in 2,4,6-trialkoxy-1,3,5-triformylbenzene, which are used to stabilize covalent organic cages or COFs, act as stereoelectronic chameleons. They increase the electrophilicity of the tritopic aldehyde and the rate of the imine bond formation but simultaneously diminish its kinetic stability in solution. We also show that aldehydes present in the solution may have a detrimental effect on the cage's kinetic stability. In addition, we observed [2 + 2] macrocycles as intermediates in the cage formation and decomposition. We propose that these intermediates represent interesting targets to explore the threshold at which an imine assembly with a rung structure may turn from thermodynamic to kinetic control. Generally, this work underscores critical factors governing the chemistry of kinetically trapped imine assemblies, such as steric bulk, (stereo)electronics, presence of catalysts, and water concentration.
亚胺有机笼的形成依赖于动态共价化学的误差校正。在此，我们展示了以高产率形成的动力学捕获的苝二酰亚胺[2 + 3]笼，并研究了取代基对其形成动力学和稳定性的影响。由此，我们确定了用于稳定共价有机笼或共价有机框架（COF）的2,4,6 - 三烷氧基 - 1,3,5 - 三甲酰基苯中的烷氧基充当立体电子变色龙。它们增加了三官能醛的亲电性和亚胺键形成的速率，但同时降低了其在溶液中的动力学稳定性。我们还表明溶液中存在的醛可能对笼的动力学稳定性产生不利影响。此外，我们观察到[2 + 2]大环作为笼形成和分解的中间体。我们提出这些中间体是探索具有梯级结构的亚胺组装从热力学控制转变为动力学控制的阈值的有趣目标。总体而言，这项工作强调了控制动力学捕获的亚胺组装化学的关键因素，如空间位阻、（立体）电子学、催化剂的存在和水浓度。
