“Click” Copper Catalyzed Azide–Alkyne Cycloaddition (CUAAC) in Aqueous Medium

Deep Eutectic Mixtures: Promising Sustainable Solvents for Metal‐Catalysed and Metal‐Mediated Organic Reactions

“…Copper‐catalysed 1,3‐dipolar cycloaddition of organic azides and terminal alkynes (CuAAC, reported independently in 2002 by Meldal38a and Sharpless38b) performed in green and biorenewable solvents fulfils some of the previously mentioned principles of Green Chemistry 1. Surprisingly, and despite the fact that this Cu I ‐catalysed cycloaddition has been performed in a variety of unconventional solvents (water,39 glycerol,40 and ionic liquids41), only one precedent of CuAAC reactions in eutectic mixtures has been reported, by König and co‐workers in 2009,42 as far as we are aware. In this seminal work, the authors studied the 1,3‐dipolar cycloaddition of benzyl azide and phenylacetylene in the LMM sorbitol/urea/NH 4 Cl as biorenewable reaction medium, in the presence of CuI (5 mol‐%) as catalyst and at 85 °C (Scheme , a).…”

Synthesis of a novel resorcin[4]arene–glucose conjugate and its catalysis of the CuAAC reaction for the synthesis of 1,4-disubstituted 1,2,3-triazoles in water

“…Simultaneous multiple CuAAC reactions have found interest in synthesis of the polymers and dendrimers and the need for efficient catalyst that can catalyze reactions in water has never been greater. 17 We have therefore investigated RG for catalyzing the di-CuAAC reactions in water of di-propargyl benzene derivatives 5b-7b with substituted benzyl azides 1a-4a (Table 3). Interestingly, the di-CuAAC reaction were completed within 45 min resulting in the desired bis-1,2,3-triazole products 22c-33c in gram quantities.…”