Key Laboratory of Radiopharmaceuticals, Ministry of Education, College of Chemistry, Beijing Normal University, Beijing 100875, China.
Molecules. 2022 Nov 17;27(22):7990. doi: 10.3390/molecules27227990.
-heterocyclic carbene (NHC) has been widely used as an organocatalyst for both umpolung and non-umpolung chemistry. Previous works mainly focus on species including Breslow intermediate, azolium enolate intermediate, homoenolate intermediate, alkenyl acyl azolium intermediate, etc. Notably, the NHC-bound alkynyl acyl azolium has emerged as an effective intermediate to access functionalized cyclic molecular skeleton until very recently. In this review, we summarized the generation and reactivity of the NHC-bound alkynyl acyl azolium intermediates, which covers the efforts and advances in the synthesis of achiral and axially chiral cyclic scaffolds via the NHC-bound alkynyl acyl azolium intermediates. In particular, the mechanism related to this intermediate is discussed in detail.
杂环卡宾（NHC）已被广泛用作反转和非反转化学的有机催化剂。以前的工作主要集中在包括 Breslow 中间体、唑鎓烯醇化物中间体、偕烯醇化物中间体、烯基酰基唑鎓中间体等物种上。值得注意的是，直到最近，NHC 键合的炔基酰基唑鎓才成为一种有效的中间体，用于获得功能化的环状分子骨架。在这篇综述中，我们总结了 NHC 键合的炔基酰基唑鎓中间体的生成和反应性，其中包括通过 NHC 键合的炔基酰基唑鎓中间体合成手性和轴向手性环状支架的努力和进展。特别是，详细讨论了与该中间体相关的机制。
