Ringexpansion of N-Heterocyclic Carbenes

我们最近的工作表明，n -杂环碳烯（NHCs）远不如一般预期的稳定。这些分子发生环膨胀反应（RER）， NHC核心结构被破坏，特别是当它们与主族元素（MGE）氢化物反应时。此外，我们还表明，在选定的MGE氢化物与NHCs的反应中，发生了脱氢元素-元素偶联；NHC在这些情况下充当氢受体。在我们未来的工作中，我们希望继续系统地研究NHCs的RERs和nhc介导的MGE氢化物的脱氢偶联，重点研究较重的13族（Ga/In）、14族（Ge/Sn/Pb）和15族（P/As/Sb）元素。此外，我们想探索使用（NHC）·EH2X型和(NHC)∙EHX2型（E = Al, Ga, In）的13族氢化物的NHC加合物分别作为亚价实体“EX”和“EX2”的合成等价物，我们想回答我们关于NHC扩环的结果是否可以转移到与MGE卤化物反应中n -杂环硅烯的可能的RER。此外，我们想尝试将RER产物转化为新型的6环碳烯或硅烯。

Our recent work demonstrates that N-heterocyclic carbenes (NHCs) are by far less stable than generally expected. These molecules undergo ring expansion reactions (RER) with destruction of the NHC core structure especially when they were reacted with main group element (MGE) hydrides. Furthermore, we have shown for the reaction of selected MGE hydrides with NHCs that dehydrogenative element element coupling occurs; the NHC serves in these cases as a hydrogen acceptor. In our future work we want to continue with the systematic investigation of RERs of NHCs and NHC-mediated dehydrocoupling of MGE hydrides, with a focus on the heavier group 13 (Ga/In), group14 (Ge/Sn/Pb), and group 15 (P/As/Sb) elements. Furthermore, we want to explore the use of NHC adducts of group 13 hydrides of the type (NHC)·EH2X and (NHC)∙EHX2 (E = Al, Ga, In), respectively, as synthetic equivalents for subvalent entities “EX” and “EX2“ and we want to answer the question whether our results on the ring exansion of NHCs can be transferred to a possible RER of N-heterocyclic Silylenes in the reaction with MGE halides. Moreover, we want to try to convert the RER products into novel 6-ring carbenes or silylenes.