An efficient one-pot procedure is described for the reduction of aryl iodides to aryl anions using a structurally simple bis-pyridinylidene electron donor, prepared in situ by treating 4-DMAP methiodide salt with base. The results show (i) that pyridinylidene carbenes can be easily used for intermolecular C-C bond formation, (ii) that bis-pyridinylidenes demonstrate superior robustness compared to electron-donor systems based on bis-imidazolylidenes, and (iii) that electron-donor strength is enhanced in the simplified DMAP-based donor. Deuterated analogues of this donor also provide mechanistic information on the source of protons when the aryl anions are quenched in situ.
本研究介绍了一种高效的单锅程序,该程序使用一种结构简单的双
吡啶亚基电子供体将芳基
碘化物还原成芳基阴离子,该电子供体是通过用碱处理 4-
DMAP 甲
碘盐原位制备的。研究结果表明:(i) 亚
吡啶碳烯可以很容易地用于分子间 C-C 键的形成;(ii) 与基于
双咪唑亚基的电子供体系统相比,双
吡啶亚基电子供体系统表现出更强的稳定性;(iii) 基于简化
DMAP 的供体增强了电子供体的强度。这种供体的氚代类似物还提供了有关原位淬灭芳基阴离子时质子来源的机理信息。