Department of Chemistry, University of Connecticut, Unit 3060, Storrs, Connecticut 06269-3060, United States.
Department of Chemistry, Purdue University, 101 Wetherill Hall, 560 Oval Drive, West Lafayette, Indiana 47907-2084, United States.
J Org Chem. 2020 Dec 4;85(23):15273-15286. doi: 10.1021/acs.joc.0c02108. Epub 2020 Nov 11.
The conversion of -aryl-porphyrins/chlorins to porphyrinoids containing nonpyrrolic heterocycles (so-called pyrrole-modified porphyrins, PMPs) along an approach we dubbed "the breaking and mending of porphyrins" is well known. However, examples are limited to the synthesis of PMPs containing up to six-membered heterocycles; the syntheses of larger rings failed. We report here hitherto unavailable eight-membered chlorin-type PMPs using an inverted "mending and breaking" approach. All examples are based on the addition of ,'dimethylurea derivatives to a -phenyl-β,β'-dioxoporphyrin, followed by oxidative cleavage of the intermediate diol adduct. We correlate the extremely nonplanar solid-state structures of three crystallographically characterized PMPs containing an eight-membered ring with their solution-state optical properties. The first examples of bis-modified, bacteriochlorin-type PMPs containing either two eight-membered rings or an eight-membered ring and an imidazolone ring are also detailed. Using other '-nucleophiles failed to either generate chlorins containing a β,β'-dihydroxypyrroline, a prerequisite for the "breaking step," or the cleavage of those substrates that did generate a diol underwent subsequent reactions that thwarted the generation of the desired PMPs. This contribution adds novel PMPs containing eight-membered rings, highlights the effects these derivatizations have on the macrocycle conformation, and how that affects their optical properties.
众所周知，通过我们称之为“破坏和修复卟啉”的方法，可以将 -芳基-卟啉/氯卟啉转化为含有非吡咯杂环的卟啉类化合物（所谓的吡咯修饰卟啉，PMPs）。然而，这些例子仅限于含有六元杂环的 PMPs 的合成；更大环的合成则失败了。我们在此报告了迄今为止尚未报道的使用反向“修复和破坏”方法合成的八元氯代卟啉型 PMPs。所有的例子都是基于将，'二甲基脲衍生物添加到 -苯基-β，β'-二氧代卟啉，然后氧化裂解中间体二醇加合物。我们将三个结晶学表征的含有八元环的 PMP 的极其非平面固态结构与其溶液态光学性质相关联。还详细介绍了含有两个八元环或一个八元环和一个咪唑啉环的双修饰的细菌叶绿素型 PMP 的第一个例子。使用其他'-亲核试剂既不能生成含有β，β'-二羟吡咯啉的氯卟啉，这是“破坏步骤”的前提，也不能裂解那些确实生成二醇的底物，随后的反应阻止了所需 PMPs 的生成。本研究增加了含有八元环的新型 PMP，强调了这些取代基对大环构象的影响，以及这如何影响它们的光学性质。
