An efficient C3–H functionalization of indazole has been demonstrated. Notably, this method involves chelation-free radical C–H nitration on 2H-indazole. The radical mechanism was confirmed by control experiments and quantum chemical calculations. The synthetic utility has been proven by the synthesis of bio-relevant benzimidazoindazoles via reductive cyclization.
展示了一种高效的indazole C3-H官能团化方法。值得注意的是,该方法涉及到2H-indazole上无螯合自由基C-H硝化反应。通过对照实验和量子
化学计算,证实了自由基机理。通过还原性环化合成
生物相关的
苯并咪唑并
吡咯,证明了其合成实用性。