We herein report an iodine-mediated formal [2 + 2 + 1] cyclization of methylketones, p-toluenesulfonyl hydrazines, and 1-aminopyridinium iodide for preparation of 4-aryl-NH-1,2,3-triazoles under metal- and azide-free conditions. Notably, this is achieved using p-toluenesulfonyl hydrazines and 1-aminopyridinium iodide as azide surrogates, providing a novel route toNH-1,2,3-triazoles. Furthermore, this
involving [3+2] cycloaddition, 1,2-acyl migration and hydrolysis produces 2H-1,2,3-triazoles via the regioselective formation of N2-carboxyalkylated triazoles. The reaction proceeds in aqueousmedia through intriguing reaction kinetics using a CuI–prolinamide catalyst system. Prolinamide promotes the novel organocatalytic 1,2-acyl migration as well as hydrolysis of the resulting N2-carboxyalkylated triazoles
Electrochemical oxidative C(sp<sup>3</sup>)–H azolation of lactams under mild conditions
作者:Zhaohua Wan、Dan Wang、Zixuan Yang、Heng Zhang、Shengchun Wang、Aiwen Lei
DOI:10.1039/d0gc00687d
日期:——
Lactam-containing structural compounds are ubiquitous in drugs and biomolecules. An electrochemical oxidative direct C(sp3)–H azolation of lactams has been reported under metal catalyst-free and external chemical oxidant-free conditions. This electrochemical C(sp3)–H/N–H coupling is characterized by its broad substrate scope of azoles and lactams under mild conditions at room temperature. Mechanistic studies suggested
The copper(I)-catalyzed azide–alkyne cycloaddition reaction has been extensively studied and widely applied in organic synthesis. However, the formation of 1,2,3-triazoles with electron-deficient azide has been a challenging problem. In this report, we have demonstrated the formation of regioselective 1,4-disubstituted 1,2,3-triazoles from various types of aryl terminal alkynes and azidoformates, which
Visible-Light Mediated Oxidative C–H/N–H Cross-Coupling between Tetrahydrofuran and Azoles Using Air
作者:Lingling Zhang、Hong Yi、Jue Wang、Aiwen Lei
DOI:10.1021/acs.joc.7b01841
日期:2017.10.6
Tetrahydrofuran is a privileged structural moiety in many important organic compounds. In this work, we have developed a simple and mild catalytic oxidative amination of tetrahydrofuran mediated by visible-light catalysis. The C(sp3)-H bond of tetrahydrofuran was activated using molecular oxygen as a benign oxidant. Besides, a variety of azoles could be tolerated, providing a green route for N-substituted