Environmental Friendly Azide‐Alkyne Cycloaddition Reaction of Azides, Alkynes, and Organic Halides or Epoxides in Water: Efficient "Click" Synthesis of 1,2,3‐Triazole Derivatives by Cu Catalyst

An efficient click synthesis of 1,2,3‐triazole derivatives from benzyl halides or alkyl halides, epoxides, terminal alkynes, and sodium azides in the presence of copper salts and relative benzimidazole salts have been developed. This procedure eliminates the need to handle potentially organic azides, which are generated in situ. A broad spectrum of substrates can participate in the process effectively to produce the desired products in good yields.