Hydroquinone-treated Cu3(BTC)2: a mixed-valence Cu(i/ii) MOF catalyst for efficient cycloadditions

We present mixed-valence Cu(I)₁Cu(II)₂(BTC)₂ [henceforth Cu(I/II)-HKUST-1], post-synthetically prepared via the hydroquinone (H₂Q) treatment of Cu(II)₃(BTC)₂ (also referred to as HKUST-1) and its subsequent catalytic activity. This Cu(I/II)-HKUST-1 exhibits exceptional structural integrity and superior catalytic performance in the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction between phenylacetylene and benzyl azide. These findings highlight the potential of mixed-valence Cu-based MOFs as effective and sustainable heterogeneous catalysts for organic transformations, paving the way for future advancements in MOF-based catalysis.