An ionic liquid containing copper(I) is introduced as a new, green, homogeneous, and reusable catalyst for click synthesis of 1,4-disubstituted-1H-1,2,3-triazoles from α-azido ketones and terminal alkynes in various solvents, especially in [bmim]BF 4 . These cyclization reactions were efficiently performed in the presence of introduced ionic liquid catalyst with short reaction times and good yields. This catalytic ionic liquid exhibits excellent activity and can be simply recovered ...