Fang Yuanyuan, Mandoj Federica, Nardis Sara, Pomarico Giuseppe, Stefanelli Manuela, Cicero Daniel O, Lentini Sara, Vecchi Andrea, Cui Yan, Zeng Lihan, Kadish Karl M, Paolesse Roberto
Department of Chemistry, University of Houston , Houston, Texas 77204-5003, United States.
Inorg Chem. 2014 Jul 21;53(14):7404-15. doi: 10.1021/ic500757a. Epub 2014 Jun 30.
The reaction of 5,10,15-tris(4-tert-butylphenyl)corrole with 2,3-bis(bromomethyl)-5,6-dicyanopyrazine provides a new example of corrole ring expansion to a hemiporphycene derivative. The ring expansion is regioselective, with insertion of the pyrazine derivative at the 5-position of the corrole ring, affording the corresponding 5-hemiporphycene. Different macrocyclic products accompany formation of the 5-hemiporphycene, depending on the reaction experimental conditions. Br-substitued 5-hemiporphycenes and the 2-Br substituted corrole were obtained in 1,2,4-trichlorobenzene, while in refluxing toluene traces of an inner core substituted corrole were observed together with a significant amount of the unreacted corrole. These results provide an important indication of the reaction pathway. The coordination behavior of the 5-hemiporphycene, together with detailed electrochemical characterization of the free-base and some metal complexes, provides evidence for the reactivity of the peripheral pyrazino group.
5,10,15-三（4-叔丁基苯基）卟啉与2,3-双（溴甲基）-5,6-二氰基吡嗪的反应为卟啉环扩展为半卟啉衍生物提供了一个新的例子。环扩展具有区域选择性，吡嗪衍生物插入到卟啉环的5-位，得到相应的5-半卟啉。根据反应实验条件的不同，在形成5-半卟啉的同时会伴随不同的大环产物。在1,2,4-三氯苯中得到了溴取代的5-半卟啉和2-溴取代的卟啉，而在回流甲苯中，观察到痕量的内核取代卟啉以及大量未反应的卟啉。这些结果为反应途径提供了重要指示。5-半卟啉的配位行为，以及游离碱和一些金属配合物的详细电化学表征，为外围吡嗪基团的反应活性提供了证据。
