Triple Action of an Attractive Deep Eutectic Solvent in the Synthesis of Aryl Nitriles and Substituted Triazoles Using a Magnetically Reusable Fe3O4@SiO2@PrNCu Catalyst

Heterogeneous Cu-catalyzed cyanation of aryl halides and Click cycloaddition of alkyl halides, sodium azide, and terminal alkynes were optimized to be cost effective and environmentally benign. A green Deep Eutectic Solvent (DES) and Fe3O4@SiO2@PrNCu magnetic catalyst was used. This new DES was designed to acts as both base and reaction promoter, beside its major role as solvent, in the studied Cu-catalyzed reactions. Additionally, hydrophobic/hydrophilic balance of employed DES, enables easier association of polar or nonpolar reactants in the course of the reactions compared to conventional green but only polar solvent such as water. Therefore, this DES provides better diffusion onto the catalyst's surfaces and thus accelerates the catalytic process. Simple experimental procedures with purposeful design and use toward DES accompanied by utilization of green and reusable catalyst could be considered as alternative features in this new protocol compared to existing methods for Cu-catalyzed reactions.