cyclization. The chemical structures of these [4]helicenes were determined on the basis of their elemental analyses and spectroscopic data. The helicity in the synthesized [4]helicene induced by the presence of the second methyl group in the fjord region is discussed in detail. The photophysical and electrochemical properties of these newly developed [4]helicenes were fully investigated by UV/Vis absorption
提出了一种新的基于
芘的 [4] 螺旋烯的便捷途径。在 nBuLi 存在下,7-叔丁基-1,3-二甲基-5-甲酰基
芘与苄基三苯基
鏻盐的 Wittig 反应得到 7-叔丁基-1,3-二甲基-5-(苯基
乙烯基)
芘,其中 4, 5-
萘环芳[4]螺旋烯,即7-叔丁基-1,3-二甲基-13-甲氧基二苯并[ij,no]四苯和7-叔丁基-1,3,12,14-四甲基二苯并[ij] ,无]四苯,是通过光诱导的分子内环化获得的。这些[4]螺旋烯的
化学结构是根据它们的元素分析和光谱数据确定的。详细讨论了由峡湾区域中第二个甲基的存在引起的合成 [4] 螺旋中的螺旋度。