CuI@MIM-SBA-15 hybrid catalyst in the ultrasound-assisted synthesis of 1,4-disubstituted 1,2,3-triazoles in water

Abstract

Click chemistry reactions transformed organic synthesis by creating enormous compound libraries connecting almost any chemical entity. The copper-catalyzed alkyne-azide cycloaddition (CuAAC) was the most versatile and efficient and transcended diverse scientific fields such as biology and materials science. Thus, the development of new methodologies based on CuAAC keeps growing. A green approach was envisioned by stabilizing the air and water-sensitive CuI over an ordered mesoporous silica/ionic liquid matrix (MIM-SBA-15). The best catalyst performance was in the water as solvent under ultrasound irradiation, which reached quantitative transformation in a short time. Then, the scope was extended to 24 compounds primarily synthesized with high yields (75–99 %); the methodology tolerated different alkynes and azides with aromatic and alkyl groups. This methodology was also successfully tested in high yields in the multicomponent synthesis of 1,4-disubstituted 1,2,3-triazoles from organic bromides, alkynes, and KN₃. The hybrid catalyst recovery and reuse were evaluated along ten reaction cycles; there was no significant loss in activity up to cycle number six (94 % yield).