Since the discovery of the first stable N-heterocyclic carbene (NHC) in the beginning of the 1990s, these divalent carbon species have become a common and available class of compounds, which have found numerous applications in academic and industrial research. Their important role as two-electron donor ligands, especially in transition metal chemistry and catalysis, is difficult to overestimate. In the past decade, there has been tremendous research attention given to the chemistry of low-coordinate main group element compounds. Significant progress has been achieved in stabilization and isolation of such species as Lewis acid/base adducts with highly tunable NHC ligands. This has allowed investigation of numerous novel types of compounds with unique electronic structures and opened new opportunities in the rational design of novel organic catalysts and materials. This Review gives a general overview of this research, basic synthetic approaches, key features of NHC–main group element adducts, and might be useful for the broad research community.

中文翻译：

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主体化学中的NHC

自从发现第一个稳定的N-杂环卡宾（NHC）在1990年代初，这些二价碳物种已成为一种常见的可用化合物，已在学术和工业研究中得到了广泛的应用。它们作为二电子供体配体的重要作用，尤其是在过渡金属化学和催化中，很难被高估。在过去的十年中，低配位主族元素化合物的化学受到了极大的研究关注。在稳定和分离具有高度可调的NHC配体的路易斯酸/碱加合物等物质方面，已经取得了重大进展。这使人们能够研究具有独特电子结构的许多新型化合物，并为合理设计新型有机催化剂和材料开辟了新的机会。