Copper complexes bearing an NHC–calixarene unit: synthesis and application in click chemistry

Abstract

Novel N-heterocyclic carbene (NHC) copper complexes supported by calix[4]arene were synthesized and showed good catalytic activity when applied in click chemistry.

Metallocalix[n]arenes in catalysis: A 13-year update

“…The Cu I -catalyzed cycloaddition of azides and alkynes (CuAAC) affording triazoles is undoubtedly the most common example of a Click-reaction [129]. In this scenario, copper complexes supported by NHC-functionalized calix [4]arene ligands (144-145, Figure 41) have recently been studied (Scheme 20) [130]. High functional group tolerance with respect to both azide and alkyne parts was observed.…”

“…Scheme 20. Selected results for the cycloaddition of azides and alkynes (CuAAC) catalyzed by 144[130].…”

Regioselective Synthesis of 1,4,5‐Trisubstituted‐1,2,3‐Triazoles from Aryl Azides and Enaminones

“…Azides 2a – 2g were prepared through an adapted Vogel's procedure . Their characterization was compared with data reported in literature …”

Design Concepts for N-Heterocyclic Carbene Ligands

“…These complexes have been applied in reactions including: Suzuki cross-coupling reactions in aqueous solution (where traditional NHCs may yield poorly soluble complexes) [89], Heck reactions [86], and copper-catalysed azide-alkyne cycloadditions [90]. In a study of Suzuki-Miyaura coupling catalysed by a calix [6]arene complex containing three nickel centres it was shown that the best results were obtained using the complexes in which the nickel centres are closest to the calix [6]arene rim [91].…”