Thiol‐Functionalized Cellulose Wrapped Copperoxide as a Green Nano Catalyst for Regiospecific Azide‐Alkyne Cycloaddition Reaction: Application in Rufinamide Synthesis

• Published in: Asian journal of organic chemistry Vol. 10; no. 12; pp. 3428 - 3433
• Main Authors: Selim, Abdul, Neethu, K. M., Gowri, Vijayendran, Sartaliya, Shaifali, Kaur, Sharanjeet, Jayamurugan, Govindasamy
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01-12-2021
• Subjects: 1,2,3-Triazoles; Additives; Alkynes; Aqueous solutions; Catalysts; Cellulose; Chemical synthesis; Click chemistry; Copper; Copperoxide nanoparticles; Cycloaddition; Green catalysis; Nanoparticles; Organic chemistry; Regioselectivity; Room temperature; Rufinamide; Triazoles
• ISSN: 2193-5807; 2193-5815
• DOI: 10.1002/ajoc.202100658

In the past few decades, click chemistry (CuAAC reaction) has seen tremendous development both in terms of catalyst designing and method development because 1,2,3‐triazoles products have shown enormous applications in various fields. The sought after azide‐alkyne cycloaddition reaction catalyzed by smaller‐sized (∼7 nm) Cu(I/II) oxide nanoparticles (CuI/IIO NPs) supported by thiol‐functionalized cellulose provided triazole products in excellent yields (90–98%) with remarkable 1,4‐regioselectivity, including the 10 g scale synthesis of a rufinamide drug intermediate. The possible reasons for this exceptional activity are the higher ratio of Cu (I), along with the smaller‐sized and homogeneously dispersed colloidal nature of CuI/IIO NPs. Most importantly, the reaction underwent industrially friendly greener conditions such as aqueous medium, room temperature, and no additives, etc., suggesting promising for practical applications. The as‐prepared catalyst was recycled and reused up to 5 cycles by simply filtering the precipitate 1,2,3‐triazoles products without losing significant activity.
The azide‐alkyne cycloaddition reaction catalyzed by homogeneously dispersed colloidal and smaller‐sized (∼7 nm) Cu(I/II) oxide nanoparticles supported by thiol‐functionalized cellulose provided triazole products in excellent yields (90–98%) with remarkable 1,4‐regioselectivity. Large‐scale synthesis of rufinamide drug precursor was achieved with conditions satisfying most of the criteria set by click chemistry, given that reaction conditions that suit environmentally benign sustainable industrially relevant processes are rare.