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

Herein, a relay strategy incorporating oxidative cross dehydrogenative coupling (CDC) and N ¹ - to N ² -isomerization is disclosed for the formal N ² -selective alkylation of triazoles with ethers under thermodynamic control conditions. By taking advantage of the different thermodynamical stabilities of N ¹ - and N ² -alkylated triazoles (3.65 kcal/mol), the initially formed N ¹ -isomers can be in situ converted into their more stable N ² -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.