直接汞转移并随后将有机汞中间体转变成相应的亚硝基衍生物,可以构建在间位(烷氧基)带有偶氮部分的杯[4]芳烃。这些化合物代表杯芳烃化学中的独特取代方式,在溶液中显示出非常不寻常的动态行为。温度相关的1 H NMR光谱证实,在杯[4]芳烃的间位中引入两个大体积部分(或什至一个),使分子刚性化,这是通过完全阻止典型的压缩锥-压缩锥证明的解决方案中的相互转换。刚性分子可用作能够与N-甲基吡啶鎓盐进行阳离子-π相互作用的配体。
Dimercuration of tetrapropoxy calix[4]arene followed by a reaction with isoamyl nitrite afforded dinitroso regioisomers with unique substitution patterns. The unusual conformational behaviour of these inherently chiral systems was revealed by the combination of dynamic NMR and residual dipolar coupling (RDC) techniques.
Shaping of calix[4]arenes via double bridging of the upper rim
作者:Petr Slavík、Václav Eigner、Pavel Lhoták
DOI:10.1039/c6ce00314a
日期:——
Direct double meta-mercuration can be used for subsequent bridging of a calix[4]arene skeleton via the installation of ketone moieties. This unprecedented substitution pattern in calixarene chemistry possesses a heavily distorted and rigid cavity capable of interactions with selected molecular guests as documented by binding of a CH2Cl2 molecule held in place by an intricate net of 10 specific (halogen
A mercuration reaction of tetrapropoxycalix[4]arene immobilized in the cone conformation gave a mixture of two dimercurated products (meta,meta and meta,para) in approximately a 1:1 ratio. Both regioisomers represent inherently chiral compounds, which makes them very attractive for design of novel receptors. As demonstrated by Pd-catalyzed arylation, the different reactivity of HgCl functions in the
monobridged compounds bearing an additional trifluoroacetamido group located distally to seven-membered rings. Both series represent inherentlychiral systems, which were successfully resolved using preparative chiral HPLC. The pure enantiomers exhibited a recognition ability towards selected chiral guest molecules as documented by the 1H NMR titration experiments. The absolute configuration of the phenyl-substituted
the construction of calix[4]arenesbearing azo moieties at the meta position (to the alkoxy groups). These compounds, representing a unique substitution pattern in calixarene chemistry, showed very unusual dynamic behaviour in solution. Temperature dependent 1H NMR spectra confirmed that the introduction of two bulky moieties (or even just one) into the meta position of calix[4]arene led to the rigidification
直接汞转移并随后将有机汞中间体转变成相应的亚硝基衍生物,可以构建在间位(烷氧基)带有偶氮部分的杯[4]芳烃。这些化合物代表杯芳烃化学中的独特取代方式,在溶液中显示出非常不寻常的动态行为。温度相关的1 H NMR光谱证实,在杯[4]芳烃的间位中引入两个大体积部分(或什至一个),使分子刚性化,这是通过完全阻止典型的压缩锥-压缩锥证明的解决方案中的相互转换。刚性分子可用作能够与N-甲基吡啶鎓盐进行阳离子-π相互作用的配体。