Tandem Cu(I)-Catalyzed Dipolar Cycloaddition-C-H Activation for the In-Flow Synthesis of N-Pyridyl-5-amino-1,2,3-triazole-4-carboxylates.

A telescoped process under continuous flow conditions is described for the synthesis of N-pyridyl-5-amino-1,2,3-triazole-4-carboxylate derivatives catalyzed by copper salts in a packed bed reactor. The synthetic approach takes first advantage of click chemistry, specifically relying on Cu(I)-catalyzed 1,3-dipolar azide-alkyne cycloaddition (CuAAC), to achieve the efficient and selective assembly of a triazole ring, followed by a copper-mediated C-H activation, that substitutes an inert C-H bond with a C-N bond, providing an environmentally acceptable and cost-effective strategy for synthesizing highly functionalized organic molecules.