Synthesis of helicenes and related compounds

α功能化联苯与乙炔和腈的金属催化反应分别生成菲和腈。这种众所周知的转化可以扩展到功能化的乙炔和腈，最终得到苝醌、苯并蒽和苯并吖啶。从适当取代的手性联苯开始，可以得到对映体纯的、轴向手性的苝醌。在这一策略的扩展中，低聚邻苯乙烯与乙炔或腈的反应将分别产生螺旋烯和氮杂螺旋烯。这样就可以合成取代螺旋烯。由于低聚苯乙烯在对映体上是纯的，所以螺旋烯的对映选择性合成是可能的。在α位置具有羧基氯功能的低邻苯乙烯多次Friedel-Crafts酰化将产生新的具有酮类功能的螺旋烯类似物，这些螺旋烯类似物可以进一步转化和功能化。这些化合物具有有趣的物理性质

Metal-catalyzed reactions of alpha-functionalized biphenyls with acetylenes and nitriles lead to phenanthrenes and nitriles, respectively. This well-known transformations shall be extended to functionalized acetylenes and nitriles to finally yield perylene quinones, benzo[de]anthracenes and benzoacridines. Starting with suitably substituted and thus chiral biphenyls would lead to enantiomerically pure, axially chiral perylene quinones. In expansion of this strategy, the reaction of oligo-ortho-phenylenes with acetylenes or nitriles would furnish helicenes and aza-helicenes, respectively. With this, the synthesis of substituted helicenes could be achieved. Since oligophenylenes are available in enantiomerically pure form, the enantioselective synthesis of helicenes is possible. Multiple Friedel-Crafts acylation of oligophenylenes with carboxyl chloride functions in the alpha positions would yield new helicene analogues with keto functions in the periphery, which could be further transformed and functionalized. Interesting physical properties can be expected for these compounds