We show that N3-MEM-protected imidazo[4,5-b]pyridines undergo efficient C2-functionalisation via direct C–H arylation. Twenty-two substituted imidazo[4,5-b]pyridines are prepared and iterative, selective elaboration of functionalised imidazo[4,5-b]pyridines gives 2,7- and 2,6-disubstituted derivatives in good yields from common intermediates. Mechanistic observations are consistent with a concerted-metallation-deprotonation mechanism facilitated by coordination of copper(I)iodide to the imidazo[4,5-b]pyridine.
我们的研究表明,N3-M
EM 保护的
咪唑并[4,5-b]
吡啶可通过直接 C-H 芳基化作用进行高效的 C2 功能化。我们制备了 22 种取代的
咪唑并[4,5-b]
吡啶,并从普通中间体中反复选择性地阐述了官能化
咪唑并[4,5-b]
吡啶,得到了产率良好的 2,7- 和 2,6- 二取代衍
生物。机理观察结果与通过
碘化
铜与
咪唑并[4,5-b]
吡啶的配位促进的协同
金属化-质子化机理一致。