Synthesis of Bifunctional Derivatives of Calix[4]arene Bearing Azidoalkyl Fragments in Cone Stereoisomeric Form

New poly-imidazolium–triazole particles by CuAAC cross-linking of calix[4]arene bis-azide/alkyne amphiphiles – a prospective support for Pd in the Mizoroki–Heck reaction

“…For the synthesis of target macrocycles containing azidoalkylimidazolium/alkynylimidazolium groups, we used our previously reported approach 22 alkylation of the corresponding N-substituted imidazoles with dichloromethyl calix [4] arene derivative 3 (Scheme 3). Foregoing synthetic strategy allows in just three steps to introduce any alkyl/imidazolium fragments into the lower/upper rims of calix [4]arene macrocyclic platform with high yields.…”

“…Foregoing synthetic strategy allows in just three steps to introduce any alkyl/imidazolium fragments into the lower/upper rims of calix [4]arene macrocyclic platform with high yields. p-H-calix [4]arene 1, presynthesized from p-tert-butyl-calix [4]arene using de-tert-butylation with AlCl 3 in the presence of phenol, 23 was treated by butyl bromide to give bis-O-butyl derivative 2, which was then involved in the Blanc chloromethylation 22 to give calix [4]arene 3 with nearly qualitative yield (Scheme 3). The nal step was reaction of calix [4]arene 3 with 1-(3-azidopropyl)-1H-imidazole or 1-(hex-5-yn-1-yl)-1H-imidazole.…”

“…1). The presence of cross peaks between protons of two neighboring benzene rings (d ¼ 7.31 and 7.04 ppm), cross peaks between protons of benzene rings with methylene protons of the imidazolium fragment, attached to neighboring benzene rings (d 20,22 and is a result of easy formation of p-quinone methide structures during ionization. 25 Aggregation behavior of 4, 5 and their mixture in aqueous solutions and their cross-linking using CuAAC…”

“…33 hex-5-yn-1-yl 4methylbenzenesulfonate, 34 11,23-bis(chloromethyl)-25,27dihydroxy-26,28-dibutoxycalix [4]arene 3 (ref. 22 ) and 11,23-bis [3-(1-(3-azidopropyl))-1H-imidazolium)methyl]-25,27-dihydroxy-26,28-dibutoxycalix [4]arene dichloride 5 (ref. 22 ) were synthesized by previously reported methods.…”

“…22 ) and 11,23-bis [3-(1-(3-azidopropyl))-1H-imidazolium)methyl]-25,27-dihydroxy-26,28-dibutoxycalix [4]arene dichloride 5 (ref. 22 ) were synthesized by previously reported methods.…”