Cribbin Liam, Twamley Brendan, Buga Nicolae, O' Brien John E, Bühler Raphael, Fischer Roland A, Senge Mathias O
School of Chemistry, Chair of Organic Chemistry, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Trinity College Dublin, The University of Dublin, Dublin, D02 R590, Ireland.
School of Chemistry, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
Beilstein J Org Chem. 2024 Nov 4;20:2784-2798. doi: 10.3762/bjoc.20.234. eCollection 2024.
Unlike their planar counterparts, classic synthetic protocols for C-C bond forming reactions on nonplanar porphyrins are underdeveloped. The development of C-C bond forming reactions on nonplanar porphyrins is critical in advancing this field of study for more complex porphyrin architectures, which could be used in supramolecular assemblies, catalysis, or sensing. In this work a library of arm-extended dodecasubstituted porphyrins was synthesized through the optimization of the classic Suzuki-Miyaura coupling of peripheral haloaryl substituents with a range of boronic acids. We report on palladium-catalyzed coupling attempts on the -, -, and -meso-phenyl position of sterically demanding dodecasubstituted saddle-shaped porphyrins. While and substitutions could be achieved, -functionalization in these systems remains elusive. Furthermore, borylation of a dodecasubstituted porphyrin's meso-phenyl position was explored and a subsequent C-C coupling showed the polarity of the reaction can be reversed resulting in higher yields. X-ray analysis of the target compounds revealed the formation of supramolecular assemblies, capable of accommodating substrates in their void.
与平面卟啉不同，用于非平面卟啉上碳 - 碳键形成反应的经典合成方案尚未得到充分发展。在非平面卟啉上开发碳 - 碳键形成反应对于推进这一研究领域以构建更复杂的卟啉结构至关重要，这些结构可用于超分子组装、催化或传感。在这项工作中，通过优化外围卤代芳基取代基与一系列硼酸的经典铃木 - 宫浦偶联反应，合成了一个手臂延伸的十二取代卟啉库。我们报道了在空间位阻较大的十二取代鞍形卟啉的α - 、β - 和meso - 苯基位置上进行钯催化偶联反应的尝试。虽然α - 和β - 取代可以实现，但这些体系中的meso - 官能化仍然难以捉摸。此外，还探索了十二取代卟啉的meso - 苯基位置的硼化反应，随后的碳 - 碳偶联反应表明反应的极性可以反转，从而提高产率。目标化合物的X射线分析揭示了超分子组装体的形成，其能够在其空隙中容纳底物。
