AbstractStarting from easily accessible precursors we describe the preparation of a series of branched oligo(2‐thienyl)‐ and oligo(2,2′‐bithienyl)‐substituted pyridine derivatives. With palladium‐catalyzed cross‐coupling reactions of pyridyl nonaflates/triflates as key steps we synthesized 2,6‐di(2‐thienyl)pyridines bridged by thiophene or benzene rings. By selective bromination of 2,6‐di(2‐thienyl)pyridine and 2,4,6‐tri(2‐thienyl)pyridine and subsequent coupling reactions an access to oligo(2,2′‐bithien‐5‐yl)‐substituted pyridine derivatives was gained. The constitution and solid state conformation of 2,6‐bis(2,2’‐bithien‐5‐yl)pyridine was determined by X‐ray analysis. This series of new pyridine‐thiophene conjugates was systematically investigated by UV/vis spectroscopy. Large Stokes shifts in the neutral and protonated form were observed. The electrochemical oxidation of two typical compounds was studied, however, these oxidations were irreversible forming a polymeric film at the anode. As a selected example, a thiophene‐bridged 2,6‐di(2‐thienyl)pyridine derivative was also investigated by scanning tunneling microscopy showing an interesting self‐assembly into a highly ordered monolayer on highly oriented pyrolytic graphite.magnified image
Some new 4‐(aryl)‐2,6‐di‐2‐naphthylpyridines and 4‐(aryl)‐2,6‐di‐2‐thienylpyridines have been prepared through three‐component condensation of 2‐acetylnaphthalene or 2‐acetylthiophene, aromatic aldehydes, and ammonium acetate in presence of 1‐(4‐sulfonylbutyl) pyridinium hydrogensulfate [(CH2)4SO3HPy][HSO4], a Brønstedacidicionicliquid as a green and reusablecatalyst in solvent‐free conditions
通过2-乙酰基萘或2-乙酰基噻吩的三组分缩合反应制备了一些新的4-(芳基)-2,6-二-2-萘吡啶和4-(芳基)-2,6-二-2-噻吩基吡啶,芳族醛和乙酸铵,在1-(4-磺酰基丁基)吡啶鎓硫酸氢盐[(CH 2)4 SO 3 HPy] [HSO 4 ]的存在下,是布朗斯台德酸性离子液体,可在无溶剂条件下用作绿色和可重复使用的催化剂。还准备了一些新的4,4'-(1,4-亚苯基)-双-(2,6-二芳基吡啶)。J.杂环化学。(2011)。