N2-Alkylation of 1,2,3-Triazoles with Ethers under Thermodynamical Control

Org Lett. 2025 Feb 14;27(6):1428-1433. doi: 10.1021/acs.orglett.4c04754. Epub 2025 Jan 31.

Abstract

Herein, a relay strategy incorporating oxidative cross dehydrogenative coupling (CDC) and N1- to N2-isomerization is disclosed for the formal N2-selective alkylation of triazoles with ethers under thermodynamic control conditions. By taking advantage of the different thermodynamical stabilities of N1- and N2-alkylated triazoles (3.65 kcal/mol), the initially formed N1-isomers can be in situ converted into their more stable N2-isomers when reaching thermodynamic equilibrium. PhI(OAc)2 has been discovered to function as both an oxidant for the CDC process and an efficient mediator for the isomerization step.