Dipartimento di Scienze del Farmaco, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
Dipartimento di Scienze Chimiche, Università di Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
Org Biomol Chem. 2020 Feb 14;18(6):1194-1203. doi: 10.1039/c9ob02352f. Epub 2020 Jan 29.
The main objective of supramolecular chemistry is to mimic the macrosystems present in nature, a goal that fits perfectly with the green chemistry guidelines. The aim of our work is to use the hydrophobic cavity of cucurbit[7]uril (CB[7]) to mimic nature for performing different dehydration and cycloaddition reactions in water. The hydrophobic cavity of CB[7] made it possible to synthesize nitrones and isoxazolidines in a one-pot fashion using water as a reaction solvent. Substituted isoxazolidines were obtained from the cycloaddition of nitrones with various styrenes and cinnamates, under microwave irradiation, with a catalytic amount of CB[7], and a moderate increase in the formation of the trans adduct was observed, compared to the reaction being carried out in toluene. The mechanism of the reaction and the inclusion of reagents and products in the CB[7] cavity have been studied and rationalized by NMR spectroscopy, ESI-MS experiments, and molecular modeling calculations.
超分子化学的主要目标是模拟自然界中存在的宏观系统，这一目标完全符合绿色化学的指导方针。我们的工作旨在利用葫芦脲（CB[7]）的疏水性空腔来模拟自然，以在水中进行不同的脱水和环加成反应。CB[7]的疏水性空腔使得使用水作为反应溶剂，以一锅法合成硝酮和异噁唑啉成为可能。用各种苯乙烯和肉桂酸盐作为亲偶极体，在微波辐射下，用催化量的 CB[7]，可以得到取代的异噁唑啉，与在甲苯中进行的反应相比，反式加成物的形成有适度增加。通过 NMR 光谱、ESI-MS 实验和分子建模计算研究并合理化了反应机理以及试剂和产物在 CB[7]空腔中的包合。
