Macrocycles of the bisbibenzyl-type are natural products that are found exclusively in bryophytes (liverworts). The molecular framework of the subtype “isoplagiochin” is of substantial structural interest because of the chirality of the entire molecule, which arises from two biaryl axes in combination with two helical two-carbon units in a cyclic arrangement. From a structural as well as a synthetic point of view we report on the total synthesis of compounds which possess more rigid two-carbon biaryl bridges like stilbene (E or Z) or even tolane moieties which were introduced starting with a Sonogashira protocol. The McMurry method proved to be a powerful tool for the cyclization to these considerably ring-strained macrocycles.
双苯基苯并型大环化合物是一类仅在苔藓植物(地钱藓)中发现的天然产物。亚型“异悬叶素”的分子框架具有重要的结构意义,因为整个分子的手性是由两个联合的联苯轴和两个螺旋的双碳单元在循环排列中产生的。从结构和合成的角度来看,我们报道了具有更刚性的双碳联苯桥的化合物的全合成,如苯乙烯(E或Z)或甚至是通过Sonogashira协议引入的甲苯基团。 McMurry方法被证明是将这些具有相当环张力的大环化合物环化的强大工具。