Kanamycin−Cu(II) Complex Catalyzed Ullmann Amine Synthesis at Room Temperature: A Tool for Mechanistic Insights into Methylene Blue Degradation

This study highlights the significance of the Ullmann coupling reaction in modern organic synthesis and advances catalytic methodologies through the introduction of a kanamycin−copper complex as a highly efficient catalyst for the synthesis of diverse N−aryl compounds. We demonstrate the catalyst's versatility by synthesizing 20 diaryl−amine instances, 21 Ar(het)−N compounds, and 10 miscellaneous examples. NMR, IR, and UV spectroscopy offer insights into the catalyst's behaviour. Additionally, DFT studies support the catalyst's proficiency in generating SO4−⋅ radicals by stabilizing with amino sugar moieties. Ex‐situ NMR experiments confirm a ternary complex‐based mechanism at concentrations below 0.1 μM. Furthermore, we showcase the degradation of methylene blue to its precursor amine under optimized conditions. Overall, this research underscores the potential of Ullmann condensation reactions in contemporary organic synthesis and contributes significantly to the advancement of catalytic methodologies. The transformative potential of kanamycin−copper (II) complexes for Ullmann amine synthesis at room temperature showcases the efficient creation of diverse N−aryl compounds via SO4−• mediated generation of Cu(III)−aryl species. Additionally, it highlights the catalyst's role in degrading methylene blue, advancing both catalytic methodologies and environmental applications.