Breslow Intermediates from Aromatic N‐Heterocyclic Carbenes (Benzimidazolin‐2‐ylidenes, Thiazolin‐2‐ylidenes)
作者:Mathias Paul、Panyapon Sudkaow、Alina Wessels、Nils E. Schlörer、Jörg‐M. Neudörfl、Albrecht Berkessel
DOI:10.1002/anie.201801676
日期:2018.7.2
We report the first generation and characterization of elusive Breslow intermediates derived from aromatic N‐heterocyclic carbenes (NHCs), namely benzimidazolin‐2‐ylidenes (NMR, X‐ray analysis) and thiazolin‐2‐ylidenes (NMR). In the former case, the diamino enols were generated by reaction of the free N,N‐bis(2,6‐diisopropylphenyl)‐ and N,N‐bis(mesityl)‐substituted benzimidazolin‐2‐ylidenes with aldehydes
我们报道了衍生自芳香性N-杂环卡宾(NHC)的难以捉摸的Breslow中间体的第一代及其表征,即苯并咪唑啉-2-亚烷基(NMR,X射线分析)和噻唑啉-2-亚基(NMR)。在前一种情况下,二氨基烯醇是由游离的N,N-双(2,6-二异丙基苯基)和N,N-双(甲磺酰基)取代的苯并咪唑啉-2-亚烷基与醛反应而生成的。在后一种情况下,以3,4,5-三甲基噻唑啉-2-亚基为起始原料。第一个基于噻唑啉-2-亚丙基的Breslow中间体的明确NMR鉴定取决于NHC和醛组分的双13 C标记。通过与过量醛形成安息香来确认酰基阴离子的反应性。