Reaction of propargylic dithioacetal 2a with BuLi gives the sulfur-substituted allenyllithium 3a which is allowed to react with a dialdehyde to yield the corresponding alternating benzeneâfuran oligoaryls 6. Functional group transformation converts the ester groups in 6 to dialdehyde 8 which can be used for the synthesis of higher homologues towards molecular wires. A combination of this furan annulation, Heck reaction and Sonogashira coupling leads to a variety of benzeneâfuranâalkene/alkyne conjugated oligomers of precise length.
丙炔基
二硫代乙酸酯 2a 与 BuLi 的反应生成了
硫替代的
丙炔基
锂化合物 3a,随后与二醛反应生成相应的交替苯–
呋喃低聚
芳烃 6。功能基团转化将 6 中的酯基团转化为二醛 8,后者可用于合成更高 homologues 以形成分子线。结合这种
呋喃环化、Heck 反应和 Sonogashira 烃偶联,能得到多种精确长度的苯–
呋喃–烯/炔 conjugated 低聚物。