Thomassen Ivar K, McCormick Laura J, Ghosh Abhik
Department of Chemistry, UiT-The Arctic University of Norway, Tromsø N-9037, Norway.
Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720-8229, United States.
ACS Omega. 2018 May 9;3(5):5106-5110. doi: 10.1021/acsomega.8b00616. eCollection 2018 May 31.
Although rather delicate on account of their propensity to undergo deiodination, β-octaiodoporphyrinoids are of considerable interest as potential precursors to novel β-octasubstituted macrocycles. Presented herein are early results of our efforts to synthesize β-octaiodocorrole derivatives. Oxidative condensation of 3,4-diiodopyrrole and aromatic aldehydes failed to yield free-base octaiodocorroles. Treatment of copper -tris(-cyanophenyl)corrole with -iodosuccinimide and trifluoroacetic acid over several hours, however, yielded the desired β-octaiodinated product in ∼22% yield. Single-crystal X-ray structure determination of the product revealed a strongly saddled corrole macrocycle with metrical parameters very close to those of analogous Cu octabromocorrole complexes. The compound was also found to exhibit an exceptionally red-shifted Soret maximum (464 nm in dichloromethane), underscoring the remarkable electronic effect of β-octaiodo substitution.
尽管β-八碘卟啉类化合物由于易于发生脱碘反应而相当不稳定，但作为新型β-八取代大环化合物的潜在前体，它们具有相当大的研究价值。本文展示了我们合成β-八碘卟吩衍生物的早期成果。3,4-二碘吡咯与芳香醛的氧化缩合反应未能生成游离碱八碘卟吩。然而，在数小时内用碘代琥珀酰亚胺和三氟乙酸处理三（对氰基苯基）铜卟吩，以约22%的产率得到了所需的β-八碘代产物。产物的单晶X射线结构测定表明，其卟吩大环呈强烈的鞍形，其结构参数与类似的铜八溴卟吩配合物非常接近。还发现该化合物的Soret最大吸收峰出现了异常的红移（在二氯甲烷中为464 nm），这突出了β-八碘取代的显著电子效应。
