Piezoelectrostatic Catalysis of the Azide–Alkyne Huisgen Cycloaddition

Electric fields are increasingly recognized for their role as 'smart reagents' that can trigger or accelerate chemical reactions. Expanding upon this concept, our research introduces an innovative method that exploits electric fields induced by ultrasound on piezoelectric nanoparticles to facilitate the azide-alkyne Huisgen cycloaddition in nonaqueous environments. The intense electric field generated around the BaTiO₃ nanoparticles, as supported by density functional theory calculations, provides the suitable conditions necessary to trigger the cycloaddition of the alkyne-functionalized nanoparticles and the azide present in the solution. To quantitatively assess the occurrence of the click cycloaddition reaction at the nanoparticle surface interface, we tacked the azide with either an electroactive ferrocene moiety or with gold nanoparticles, which act as surface Raman enhancers. These experiments not only provide experimental validation of our approach, but also highlights the potential of piezoelectrostatic catalysts in enhancing the scalability of electrostatic catalysis.