aldehydes to form acyl radicals, which can engage in addition to pyridinium substrates. Remarkably, the use of N-methoxypyridinium salts preferentially gives the C2-acylated pyridines, and the site selectivity can be switched from C2 to C4 by using N-aminopyridinium salts. The utility of this transformation was further demonstrated by the late-stage functionalization of complex biorelevant molecules and by
通过使用N-甲氧基或N-
氨基吡啶鎓盐,开发了一种可见光诱导的
吡啶鎓盐位点C–H酰化的策略,为获得高价值的C2和C4酰化
吡啶提供了强大的合成工具。由
吡啶鎓盐光催化产生的甲氧基或a基可以从容易获得的醛中夺取氢原子,形成酰基基团,该基团除
吡啶鎓底物外还可以参与。明显地,使用N-甲氧基
吡啶鎓盐优先给出C2-酰化
吡啶,并且通过使用N可以将位点选择性从C2切换为C4。-
氨基吡啶鎓盐。复杂的
生物相关分子的后期功能化以及酰基自由基在光催化自由基级联反应中的应用,进一步证明了这种转化的效用。