A Peerless Aproach: Organophotoredox/Cu(I) Catalyzed, Regioselective, Visible Light Facilitated, Click Synthesis of 1,2,3-Triazoles via Azide–Alkyne [3 + 2] Cycloaddition

A visible light initiated, mild, one pot, multicomponent copper catalyzed azide alkyne [3 + 2] cycloaddition in the presence of organo photoredox catalyst Eosin Y using EtOH:H 2 O as reaction medium for the synthesis of substituted 1,2,3-triazoles is reported. A facile regioselective ring opening of epoxides followed by 1, 3 dipolar cycloaddition with alkynes under CFL (Compact fluorescent light) irradiation as a source of visible light resulting in the formation of C–N bonds, is the characteristic feature of the present strategy. Scope of the present protocol is further extended by using benzyl chloride in place of epoxide. Graphical Abstract