咪唑并[1,5- a ]吡啶离子被鉴定为通过有效的三组分偶联反应获得的高发射性和水溶性荧光团。已显示出与多杂环核心共轭的基团的合成修饰深刻地影响了这些分子的发射特性。值得注意的是,发现官能化的咪唑并[1,5- a ]吡啶鎓离子的两个结构异构体表现出不同的去激发途径,这引起荧光开启或对pH值变化的比例响应。
Efficient, Single-Step Access to Imidazo[1,5-<i>a</i>]pyridine <i>N</i>-Heterocyclic Carbene Precursors
作者:Johnathon T. Hutt、Zachary D. Aron
DOI:10.1021/ol202134n
日期:2011.10.7
The three-component coupling reaction of substituted picolinaldehydes, amines, and formaldehyde to produce imidazo[1,5-a]pyridinium ions is reported, providing an efficient method for the preparation of N-heterocyclic carbenes (NHCs). Reactions proceed in high yields under mild conditions, allowing the incorporation of diverse functionality and chiral substituents. Higher order condensations are also described that provide access to multidentate NHC ligands useful for a variety of applications.