The recent development of β‐cyclodextrin‐based catalysts system in click reactions: A review

Abstract

A significant challenge for scientists today is to design green and eco‐friendly catalysts based on green chemistry with high catalytic performance and recycling properties. Many studies have aimed to address environmental issues by developing green chemical processes and catalysts that reduce the production of harmful substances. β‐Cyclodextrin (β‐CD), a class of cyclic oligomers, has garnered considerable attention in recent decades. It has been utilized as a green alternative catalyst in various organic conversions, demonstrating satisfactory catalytic activity and improved efficiency of organic reactions. The availability, non‐toxicity, low cost, renewability, and high performance in organic transformations are several benefits of cyclodextrins that have attracted interest from research groups worldwide. The click reaction is well‐known in green chemistry for its high selectivity and efficiency in producing 1,2,3‐triazoles with significant medicinal activities. This reaction involves aryl/alkyl halides, alkynes, and NaN3 under ambient conditions to generate necessary scaffolds called 1,2,3‐triazoles. Therefore, finding green approaches for synthesizing 1,2,3‐triazoles is of great interest. In recent decades, significant advancements have been made in developing metal‐catalyzed click reactions to synthesize 1,2,3‐triazole derivatives. Carolyn Bertozzi, Morten Meldal, and Barry Sharpless were awarded the Nobel Prize in Chemistry in 2022 for their contributions to the foundations of click and bio‐orthogonal chemistry. In transition, metal‐catalyzed click reactions, using modified β‐CD derivatives as catalysts is particularly advantageous because of their valuable catalytic properties and their ability to form inclusion complexes with different metals. This review focuses on the catalyzed click reaction using β‐CD‐based catalysts to prepare triazoles. Using biodegradable β‐CD has made the method safe, sustainable, and eco‐friendly. The click reaction has provided access to various 1,2,3‐triazoles essential in pharmaceutical products and exhibits diverse biological activities. The specific purpose of this review is to summarize the application of β‐CD‐based catalyst systems in click reactions.