Selective ipso-nitration of tert-butylcalix[4]arene 1,3-diethers: X-ray structure of an unexpected side product
摘要:
1,3-Diether derivatives of tert-butylcalix[4] arene can be selectively nitrated at the para-position of the phenolic units, In this way calix[4]arenes bearing tert-butyl and nitro groups at the upper rim in alternating sequence are easily available in yields up to 75%, Ipso-attack may also occur ortho to the phenolic hydroxy group leading in a side reaction to macrocyclic compounds with two 6-nitrocyclohexa-2,4-dienone units. Both types of structures were established by single crystal X-ray analysis.
Towards Supramolecular Fixation of NOX Gases: Encapsulated Reagents for Nitrosation
作者:Yanlong Kang、Grigory V. Zyryanov、Dmitry M. Rudkevich
DOI:10.1002/chem.200400939
日期:2005.3.4
nitrosated with much lower yields (<8 %). Enantiomerically pure encapsulating reagent 2 d was tested for nitrosation of racemic amide 5 t, showing modest but reproducible stereoselectivity and approximately 15 % ee. Given high affinity to NO+ species, which can be generated by a number of NOX gases, these supramolecular reagents and materials may be useful for NOX entrapment and separation in the environment
Microwave-assisted Alkylation of p-tert-butylcalix[4]arene Lower Rim: The Effect of Alkyl Halides
作者:Vladimir A. Burilov、Ramil I. Nugmanov、Regina R. Ibragimova、Svetlana E. Solovieva、Igor S. Antipin、Alexander I. Konovalov
DOI:10.1016/j.mencom.2013.03.022
日期:2013.3
Alkylation of p-tert-butylcalix[4]arenes with alkyl bromides or iodides under microwave irradiation affords mostly the corresponding distal disubstituted ethers, whereas in case of alkyl chlorides reasonable yields of monoethers were achieved.
Selective ipso-nitration of tert-butylcalix[4]arene 1,3-diethers: X-ray structure of an unexpected side product
1,3-Diether derivatives of tert-butylcalix[4] arene can be selectively nitrated at the para-position of the phenolic units, In this way calix[4]arenes bearing tert-butyl and nitro groups at the upper rim in alternating sequence are easily available in yields up to 75%, Ipso-attack may also occur ortho to the phenolic hydroxy group leading in a side reaction to macrocyclic compounds with two 6-nitrocyclohexa-2,4-dienone units. Both types of structures were established by single crystal X-ray analysis.
A low dielectric constant material synergized by calix[4]arene and benzocyclobutene units
作者:Chengcheng Zhou、Ding Shen、Xingpeng Chai、Boyang Shi、Wenya Zhu、Guowei Wang
DOI:10.1039/d3tc01554h
日期:——
the properties of insulating dielectrics. As a supramolecular compound, calix[4]arene has a unique cavity structure, showing potential for a low-k material. We herein reported a novel strategy to functionalize the 4-tert-butylcalix[4]arene with different numbers of benzocyclobutene (BCB) units (2 or 4) and spacers (–(CH2)3– or –(CH2)6–) by sequential substitution and hydrosilylation reactions. These
半导体工业的快速发展对绝缘电介质的性能提出了更高的要求。作为一种超分子化合物,杯[4]芳烃具有独特的空腔结构,显示出作为低k材料的潜力。我们在此报道了一种新策略,用不同数量的苯并环丁烯(BCB)单元(2或4)和间隔基(–(CH 2)3 –或–(CH 2)6对4-叔丁基杯[4]芳烃进行功能化–) 通过连续取代和氢化硅烷化反应。这些前体可以在加热下固化以形成交联膜。通过差示扫描量热法(DSC)测量筛选优化固化条件。结合使用含有杯[4]芳烃但不含BCB单元的前驱体的对比实验,广角X射线散射(WAXS)图和热分析提供了有力的证据,证明薄膜的高热稳定性(玻璃化转变温度(T g )> 110 °C,5 wt%损失温度> 367 °C,热膨胀系数< 87.88 ppm °C -1 )主要由杯[4]芳烃贡献,而优异的介电性特性(最低介电常数D k= 2.23 和平均介电损耗D f < 1.5 × 10 -3