One-pot, two-step synthesis of 7-methylene-1,5-piperazine-fused 1,2,3-triazoles

Abstract

A facile, one-pot two-step synthesis of 7-methylene-1,5-piperazine-fused 1,2,3-triazole derivatives has been developed. The protocol employs an N-allylation of N-propargylated amines with 2,3-dibromopropene in the presence of K₂CO₃ in DMSO and a CuI-catalyzed [3 + 2] cycloaddition reaction of the synthetic N-(2-bromoallyl)-N-propargyl amines with sodium azide sequentially. Such a method provides methylene-substituted 1,2,3-triazole fused piperazines with some advantages such as simple operation, high efficiency and good product yield (80–91%) through readily available starting materials.

Graphical Abstract

Keywords:

• [3 + 2] cycloaddition
• 2,3-dibromopropene
• 7-methylene-1,5-piperazine-fused 1,2,3-triazoles
• N-propargylated amines
• N-allylation
• one-pot procedure

Additional information

Funding

We are grateful to the National Natural Science Foundation of China [No. 21762022], the Research Program of Jiangxi Province Department of Education [No. GJJ160289, GJJ11380], the Opening Foundation of National Research Center for Carbohydrate Synthesis [No. GJDTZX-KF-201414] and the Opening Foundation of Key Laboratory of Functional Small Organic Molecule of Ministry of Education [No. KLFS-KF-201411] for the financial support.