Cross-Dehydrogenative Coupling of Azoles with α-C(sp3)-H of Ethers and Thioethers under Metal-Free Conditions: Functionalization of H-N Azoles via C-H Activation

A metal-free cross-dehydrogenative coupling method for the synthesis of N-substituted azoles has been developed. The TBAI/TBHP system catalyzed the coupling of azoles with ethers and thioethers via a-C(sp(3))H activation. Under the optimized conditions, a diverse range of un/substituted azoles such as 1H-benzimidazole, 9H-purine, 1H-benzotriazole, 1H-1,2,3-triazole, 1H-1,2,4-triazole, and 1H-pyrazole were successfully employed for coupling with various ethers and thioethers such as tetrahydrofuran, tetrahydropyran, 1,4-dioxane, diethyl ether, tetrahydrothiophene, and 1,3-dithiolane.