Copper-Catalyzed <i>N</i>-Arylation of Azoles and Mannich-Type Coupling of Ketones and Azoles under Metal-Free Conditions
作者:Kai Sun、Zhonghong Zhu、Jingjing Sun、Lulu Liu、Xin Wang
DOI:10.1021/acs.joc.5b02593
日期:2016.2.19
five-membered heterocycles with azoles. Five-membered heterocycles bearing an acetyl group also underwent a Mannich-type reaction with activated azoles to give the corresponding β-amino ketonesundermetal-freeconditions. These reactions exhibited wide substrate scope, high functional group tolerance, and ease of operation, making them useful tools with numerous potential applications in synthetic chemistry
Here, we report the copper-catalyzed C2 selective cross-dehydrogenative C-N bond formation of azines with azoles. This straightforward method enables us to address the key limitation of prior N-O activation strategy in C2 amination of azines. The wide substrate scope, high functional group tolerance, and ease of operation of the present method are expected to promote its potential application in synthetic chemistry.
C–H Imidation and Dual C–H Bond Aminobromination of Five-Membered Heterocycles
Here, we report a practical C-H imidation of five-membered heterocycles under metal-free conditions. We also report the first dual C-H bond aminobromination of thiophenes, with benzotriazole, saccharin, 1,2,4-triazole, benzimidazole, pyrazole, 4-bromopyrazole, 5-methyltetrazole, and dibenzenesulfonimides as effective amine sources. Mechanistic studies support the radical pathway of the imidation and aminobromination reactions.