The title 1,2-bis(purin-6-yl)acetylenes, -diacetylenes, -ethylenes and -ethanes were prepared as covalent base-pair analogues starting from 6-ethynylpurines and 6-iodopurines by the Sonogashira cross-coupling or oxidative alkyne-dimerization reactions followed by hydrogenations. 6-[(1,3-Dimethyluracil-5-yl)ethynyl]purine (11) was prepared analogously and hydrogenated to the corresponding purine-pyrimidine conjugates linked via vinylene and ethylene linkers. Unlike the cytostatic bis(purin-6-yl)acetylenes and -diacetylenes, the purine-pyrimidine conjugates were inactive. Crystal structures of bis(purin-6-yl)acetylene 6a, -diacetylene 8a and -ethane 5a were determined by single-crystal X-ray diffraction.
1,2-双(嘌呤-6-基)乙炔,-二炔,-乙烯和-乙烷作为共价碱对类似物从6-乙炔基嘌呤和6-碘嘌呤出发,通过Sonogashira交叉偶联或氧化炔基二聚反应制备,随后进行氢化反应。类似地制备了6-[(1,3-二甲基尿嘧啶-5-基)乙炔基]嘌呤(11),并将其氢化为相应的嘌呤-嘧啶共轭物,通过乙烯和乙烷连接器连接。与细胞静止作用的双(嘌呤-6-基)乙炔和-二炔不同,嘌呤-嘧啶共轭物无活性。通过单晶X射线衍射测定了双(嘌呤-6-基)乙炔6a,-二炔8a和-乙烷5a的晶体结构。