Highly Efficient Ultrasonic‐Assisted CuCl‐Catalyzed 1,3‐Dipolar Cycloaddition Reactions in Water: Synthesis of Coumarin Derivatives Linked with 1,2,3‐Triazole Moiety

Abstract

in Wiley Online Library (wileyonlinelibrary.com).By introducing ultrasound irradiation into "on water" CuCl-catalyzed 1,3-dipolar Huisgen cycloaddition, the reaction efficiencies were notably promoted toward a wide variety of applicable azides and alkynes at room temperature, and a series of coumarin derivatives linked with 1,2,3-triazole moiety were synthesized using the optimized conditions.

Recent Progress of Cu-Catalyzed Azide-Alkyne Cycloaddition Reactions (CuAAC) in Sustainable Solvents: Glycerol, Deep Eutectic Solvents, and Aqueous Media

“…An additional example of ligand-free CuAAC protocols in neat water includes the use of ultrasound irradiation [67] to enhance the activity of a Cu(I) salt (i.e., CuCl) as catalyst (Scheme 8). In this sense, Chen, Qu and co-workers used CuCl (10 mol%) to build 1,4-disubstituted 1,2,3-triazoles at room temperature upon ultrasound irradiation (150 W), including a family of triazoles generated from coumarine-derived alkynes or azides thereby granting access to highly functionalized heterocycles that were isolated in ca.…”

“…In this sense, Chen, Qu and co-workers used CuCl (10 mol%) to build 1,4-disubstituted 1,2,3-triazoles at room temperature upon ultrasound irradiation (150 W), including a family of triazoles generated from coumarine-derived alkynes or azides thereby granting access to highly functionalized heterocycles that were isolated in ca. 90% yield (see Scheme 8a,b) [67]. Remarkably, lower yields were reached in the absence of ultrasonic power, even in the presence of trimethylamine as co-catalyst, or when using mixtures H 2 O/VOCs or pure organic solvents (DMSO, DMF, toluene or t BuOH) instead of neat water as a reaction medium.…”

Recent Advances and Prospects of Organic Reactions “On Water”

“…Ultrasonic assisted 1,3‐dipolar Huisgen cycloaddition for the synthesis of 1,2,3‐triazole moiety by the reaction of azides and alkynes was reported . The reaction was carried out using CuCl as catalyst on water at room temperature (Scheme ).…”

Cu‐Catalyzed Synthesis of Coumarin‐1,2,3‐Triazole Hybrids connected with Quinoline or Pyridine Framework**

“…Cu(I)‐Nanoparticles utilized as an heterogenous catalyst for greener conditions [29] . Several improvements have been used in the conditions of Click Chemistry, such as one‐pot reactions, [25,27] photochemical, [30] ultrasonic [31] ball‐milling [29b] or electrochemical reactions [32] . The use of [Ru]‐catalysts in ruthenium‐catalyzed azide alkyne cycloaddition reaction (RuAAC), resulted in the synthesis of 1,5‐disubstituted 1,2,3‐triazoles [33] .…”