One-Pot, Three-Component Synthesis of 1-(2-Hydroxyethyl)-1H-1,2,3-triazole Derivatives by Copper-Catalyzed 1,3-Dipolar Cycloaddition of 2-Azido Alcohols and Terminal Alkynes under Mild Conditions in Water

✍ Scribed by Hashem Sharghi; Mona Hosseini-Sarvari; Fatemeh Moeini; Reza Khalifeh; Alireza Salimi Beni

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: German
• Weight: 247 KB
• Volume: 93
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.200900226

✦ Synopsis

Abstract

A safe, efficient, and improved procedure for the regioselective synthesis of 1‐(2‐hydroxyethyl)‐1__H__‐1,2,3‐triazole derivatives under ambient conditions is described. Terminal alkynes reacted with oxiranes and NaN~3~ in the presence of a copper(I) catalyst, which is prepared by in situ reduction of the copper(II) complex 4 with ascorbic acid, in H~2~O. The regioselective reactions exclusively gave the corresponding 1,4‐disubstituted 1__H__‐1,2,3‐triazoles in good to excellent yields. This procedure avoids the handling of organic azides as they are generated in situ, making this already powerful click process even more user‐friendly and safe. The remarkable features of this protocol are high yields, very short reaction times, a cleaner reaction profile in an environmentally benign solvent (H~2~O), its straightforwardness, and the use of nontoxic catalysts. Furthermore, the catalyst could be recovered and recycled by simple filtration of the reaction mixture and reused for ten consecutive trials without significant loss of catalytic activity. No metal‐complex leaching was observed after the consecutive catalytic reactions.