Recyclable Hydrotalcite-Supported Copper Catalysts for Green and Regioselective Click Synthesis of 1,2,3-Triazoles

TL;DR

A recyclable copper catalyst supported on hydrotalcite efficiently synthesizes triazoles in water under mild conditions, promoting green chemistry.

Contribution

A sustainable hydrotalcite-supported Cu(I) catalyst enables rapid, regioselective triazole synthesis in water with excellent recyclability.

Findings

Cu₂O@LDH-01 achieved quantitative conversions in 5 minutes under ultrasound in water.

The catalyst maintained activity over five cycles without significant loss.

The system showed regioselectivity across diverse alkynes and azides.

Abstract

This work reports
a sustainable and highly efficient catalytic
system based on cuprous oxide nanoparticles supported on hydrotalcite
(Cu

2

O@LDH-01) for
the regioselective synthesis of 1,2,3-triazoles via copper-catalyzed
azide–alkyne cycloaddition (CuAAC) in aqueous media. The catalyst
was comprehensively characterized by XRD, FTIR, BET, TGA, and STEM-EDX
analyses, confirming the successful incorporation and uniform dispersion
of the Cu­(I) species within the layered double hydroxide structure.
Under mild and additive-free conditions, Cu

2

O@LDH-01 afforded quantitative conversions
in water within only 5 min under ultrasound irradiation, emphasizing
the crucial role of acoustic cavitation in enhancing mass transfer
and catalytic performance. The system exhibited regioselectivity across
a broad range of alkynes and azides, with both electronic and steric
factors governing reactivity. Furthermore, the catalyst could be readily
recovered and reused over five consecutive cycles without a noticeable
loss of activity, demonstrating its robustness and practical applicability.
Overall, this study highlights hydrotalcite-supported Cu­(I) catalysts
as a green, recyclable, and scalable platform for click chemistry,
in full alignment with the principles of sustainable synthesis and
waste minimization.

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