An intramolecularly self-templated synthesis of macrocycles: self-filling effects on the formation of prismarenes
作者:Paolo Della Sala、Rocco Del Regno、Luca Di Marino、Carmela Calabrese、Carmine Palo、Carmen Talotta、Silvano Geremia、Neal Hickey、Amedeo Capobianco、Placido Neri、Carmine Gaeta
DOI:10.1039/d1sc02199k
日期:——
Ethyl- and propyl-prism[6]arenes are obtained in high yields and in short reaction times, independent of the nature and size of the solvent, in the cyclization of 2,6-dialkoxynaphthalene with paraformaldehyde. PrS[6]Et or PrS[6]nPr adopt, both in solution and in the solid state, a folded cuboid-shaped conformation, in which four inward oriented alkyl chains fill the cavity of the macrocycle. On these
在 2,6-二烷氧基萘与多聚甲醛的环化过程中,乙基和丙基棱柱[6]芳烃的产率高且反应时间短,与溶剂的性质和大小无关。PrS[6] Et或PrS[6] n Pr在溶液和固态中均采用折叠长方体形构象,其中四个向内取向的烷基链填充大环的空腔。在此基础上,我们提出PrS[6] Et或PrS[6] n Pr的环化是通过分子内热力学自模板效应发生的。换句话说,PrS[6] Et或PrS[6] n Pr内部空腔的自填充稳定了它们的长方体结构,推动了平衡的形成。溶液和固态的分子识别研究表明,将客体引入大环空腔中,通过诱导配合机制迫使长方体支架打开。在五聚体PrS[5]的内腔络合过程中,会发生类似的从闭合状态到开放状态的构象变化。这些结果代表了通过分子内自模板效应驱动的热力学控制环化过程的罕见例子,可用于新型大环化合物的合成。