Azide–Akyne Click Approach to the Preparation of Dendrimer–Type Multi(thia)calix[4]arenes with Triazole Linkers

Abstract

The design of polymacrocyclic structures is of high importance for the improvement of recognition ability to various guests. We present a convenient approach towards two types of dendrimer-shaped pentakis-thiacalix[4]arenes with triazolyl linkers using the click reaction of tetraazidoalkoxycalixarenes with monoalkynyloxy derivatives, as well as tetraalkynyloxycalixarenes with monoazidoalkoxy derivatives. Mitsunobu alkylation of hydroxyl groups has been employed to afford tetrasubstituted derivatives in 1,3-alternate configuration. A facile procedure for the synthesis of monosubstituted cone precursors in high yields by the hydrolysis of one ether fragment in disubstituted counterparts under basic conditions (n-BuNH 2 or NaN 3 in DMF) has been suggested and optimized. CuAAC reaction has been conducted in microwave reactor and on a hot plate. It has been found that microwave irradiation promotes the reaction and the yields of products are as high as 40-80 %.

Thermally Stable Nitrothiacalixarene Chromophores: Conformational Study and Aggregation Behavior

“…However, electron-withdrawing substituents decrease nucleophilicity of phenolate-anion and require higher temperatures and longer reaction time to access type III structures. Due to the base-promoted ether-group cleavage in distally disubstituted thiacalixarenes, which is enhanced at elevated temperatures and longer reaction times [26,27], nitrocalixarene 1 was alkylated with 1-dodecanol and 1-octanol (synthesis, monolayer formation, and optical characteristics of the product 2b was published as a preliminary result in [28]) (Scheme 1). Interestingly, the extent of lower rim substitution could be controlled by reaction temperature.…”

Synthesis of Water-Soluble Amino Functionalized Multithiacalix[4]arene via Quaternization of Tertiary Amino Groups

“…The tendency to form inclusion compounds [ 23 ], the availability of mono-, di-, tri- and tetra-substituted derivatives [ 24 , 25 , 26 ], as well as the existence of spatially pre-organized conformational isomers [ 27 ] ( cone , partial cone , 1,2- and 1,3-alternate ) make the thiacalix[4]arene platform attractive for the preparation of polyfunctional dendrimers with well-oriented spatial organization. The literature presents a limited number of publications on the synthesis of multi(thia)calix[4]arene systems [ 28 , 29 ]. Previous studies have used a wide variety of reactions for the preparation of multi(thia)calix[4]arene systems, e.g., O -alkylation [ 30 ], hydrosilylation [ 31 ], amide formation [ 32 , 33 ], and “click” reactions [ 28 , 34 ].…”

“…The literature presents a limited number of publications on the synthesis of multi(thia)calix[4]arene systems [ 28 , 29 ]. Previous studies have used a wide variety of reactions for the preparation of multi(thia)calix[4]arene systems, e.g., O -alkylation [ 30 ], hydrosilylation [ 31 ], amide formation [ 32 , 33 ], and “click” reactions [ 28 , 34 ]. However, there are almost no convenient approaches to the synthesis of multi(thia)calix[4]arenes with different functional groups on the surface in existing examples of multi(thia)calix[4]arene systems.…”

A new approach to the synthesis of thiacrowns on a thiacalix[4]arene scaffold

“…Во-первых, относительной лёгкостью снятия О-алкильных групп в присутствии оснований, что было нами недавно обнаружено [12]. Во-вторых, низкой реакционной способностью бромэтильных групп по отношению к нуклеофилам, которая отмечалась ранее и обусловлена стерическими препятствиями соседних трет-бутильных групп подходу нуклеофила [13,14].…”

“…Спектральные характеристики и константы соединений 2-СоединениеЯМР (CDCl 3 , δ, м. д., J/Гц) 13. С ЯМР (CDCl 3 , δ, м.…”