Chelation-Assisted Interrupted Copper(I)-Catalyzed Azide-Alkyne-Azide Domino Reactions: Synthesis of Fully Substituted 5-Triazenyl-1,2,3-triazoles

Org Lett. 2021 Jan 15;23(2):334-339. doi: 10.1021/acs.orglett.0c03838. Epub 2020 Dec 24.

Abstract

We describe the synthesis of 1,4-(disubstituted)-5-triazenyl-1,2,3-triazoles through a ligand-free domino copper(I)-catalyzed azide-alkyne-azide process of chelating aryl azides bearing N-P═O, P═O, and SO3H groups at the ortho position with a wide variety of acetylenes. DFT calculations reveal that Cu-chelation is a crucial factor in the interception of the CuAAC intermediate by the azide. The crystal structure of the catalytic species has been determined by X-ray diffraction.