Copper-Catalysed Multicomponent Click Synthesis of 5-Alkynyl 1,2,3-Triazoles under Ambient Conditions

Abstract

Copper(I) oxide has been found to effectively catalyse the multicomponent click synthesis of fully substituted 5-alkynyl 1,2,3-triazoles from organic halides, sodium azide, and terminal alkynes in methanol under ambient conditions.

Synthesis, Structural Characterization and Catalytic Activities of Sulfur‐Functionalized NHC–Copper(I) Complexes

“…This observation might be the result of consecutive reactions: Glaser coupling and 1,3‐dipolar cycloaddition. Such regioselective formation of different substituted 1,4,5‐trisubstituted 1,2,3‐triazoles was previously reported by Gerard et al The same outcome can also be explained by the fact that complex 8Cl may activate the 5‐position in 1,4‐disubstituted 1 H ‐1,2,3‐triazole, as has been shown by Alonso et al…”

“…This observation might be the result of consecutive reactions: Glaser coupling and 1,3-dipolar cycloaddition. Such regioselective formation of different substituted 1,4,5-trisubstituted 1,2,3-triazoles was previously reported by Gerard et al [16] The same outcome can also be explained by the fact that complex 8Cl may activate the 5position in 1,4-disubstituted 1H-1,2,3-triazole, as has been shown by Alonso et al [17] To gain more information on the activity of the obtained copper complexes, we investigated their properties in another three-component transformation known as A 3 coupling reaction. Products of this multicomponent one-pot synthesis are suitable synthetic building blocks for amino derivatives.…”

Free‐radical‐mediated copper‐catalyzed triazole formation under UV‐irradiation

“…Also, attention has been given for the development of single‐step multi‐component reactions, because of the high degree of atom economy, applications in combinatorial chemistry and diversity‐oriented synthesis . Multi‐component strategies for click reaction where inorganic azide salts, such as sodium azide and alkyl halide, may participate in an in situ nucleophilic substitution reaction to produce organic azide molecules that further could undergo cycloaddition with the alkyne dipolarophile in a single‐step one‐pot reaction and similar types of protocol are also evident in the literature …”

“…[28] Multicomponent strategies for click reaction where inorganic azide salts, such as sodium azide and alkyl halide, may participate in an in situ nucleophilic substitution reaction to produce organic azide molecules that further could undergo cycloaddition with the alkyne dipolarophile in a single-step one-pot reaction and similar types of protocol are also evident in the literature. [38,39] In this work, we were also interested to implement Cu-PA-MPEG catalyst for the single-step multicomponent reaction using aryl halide, sodium azide and alkyne under different photonic conditions. The results are shown graphically in Figure 3 and also in Table 3.…”

CuII‐Catalyzed Oxidative Formation of 5‐Alkynyltriazoles

“…Presumably the azide ion acted as a ligand to copper(I/II) as it was used in excess in both procedures. MeOH was emphasized as the only solvent that was effective in the procedure in entry 3 . The method listed in entry 4 also used an alcohol as the solvent (EtOH or MeOH) .…”