Solvent-Free Copper-Catalyzed Azide-Alkyne Cycloaddition under Mechanochemical Activation
Laura Rinaldi,
Katia Martina,
Francesca Baricco,
Laura Rotolo,
Giancarlo Cravotto
Affiliations
Laura Rinaldi
Dipartimento di Scienza e Tecnologia del Farmaco and NIS—Centre for Nanostructured Interfaces and Surfaces, University of Turin, Via P. Giuria 9, Turin 10125, Italy
Katia Martina
Dipartimento di Scienza e Tecnologia del Farmaco and NIS—Centre for Nanostructured Interfaces and Surfaces, University of Turin, Via P. Giuria 9, Turin 10125, Italy
Francesca Baricco
Dipartimento di Scienza e Tecnologia del Farmaco and NIS—Centre for Nanostructured Interfaces and Surfaces, University of Turin, Via P. Giuria 9, Turin 10125, Italy
Laura Rotolo
Dipartimento di Scienza e Tecnologia del Farmaco and NIS—Centre for Nanostructured Interfaces and Surfaces, University of Turin, Via P. Giuria 9, Turin 10125, Italy
Giancarlo Cravotto
Dipartimento di Scienza e Tecnologia del Farmaco and NIS—Centre for Nanostructured Interfaces and Surfaces, University of Turin, Via P. Giuria 9, Turin 10125, Italy
The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e., milling time, revolutions/min, size and milling ball number) have been optimized. This new, efficient, facile and eco-friendly procedure has been tested on a number of different substrates and in all cases afforded the corresponding 1,4-disubstituted 1,2,3-triazole derivatives in high yields and purities. The final compounds were isolated in almost quantitative overall yields after simple filtration, making this procedure facile and rapid. The optimized CuAAC protocol was efficiently applied even with bulky functionalized β-cyclodextrins (β-CD) and scaled-up to 10 g of isolated product.
