Chiraloptical properties of adducts derived from cyclic nitrones and 2(5H)-furanones. Combined experimental and theoretical studies
作者:Sebastian Stecko、Jadwiga Frelek、Marek Chmielewski
DOI:10.1016/j.tetasy.2009.06.017
日期:2009.8
(TD-DFT) and molecular modelling calculations supported additionally by X-ray diffraction analysis, was applied. Model compounds were obtained via the 1,3-dipolar cycloaddition of 2(5H)-furanones and five- and six-membered cyclic nitrones. In addition, cycloadducts either with or without an additional interfering chromophore were selected. A comparison of the recorded ECD spectra with those simulated
所述Bucourt罗格朗经验规则的有效性,这在与内酯Ñ→π的符号在具有内酯单元的α -碳原子涉及的配置*的5-5-在电子圆二色性观察到过渡(ECD)光谱研究了5和5-5-6稠合杂环系统。为此,将ECD光谱,时间依赖的密度泛函理论(TD-DFT)和X射线衍射分析额外支持的分子模型计算相结合。通过2(5H)的1,3-偶极环加成获得模型化合物)呋喃酮和五元和六元环状硝酮。另外,选择有或没有其他干扰生色团的环加合物。将记录的ECD光谱与通过TD-DFT计算模拟得到的ECD光谱进行比较,可以合理解释在210–230 nm光谱范围内观察到的激发。通常,计算证实了布考特-勒格朗法则的有效性,并证明了ECD可用作本文研究系统的三维分子结构的高度灵敏的探针。然而,在一些被BnO基团取代的5-5-6稠合系统中观察到了显着的行为。在这些情况下,