The efficient preparation of four C-3-symmetric (star-shaped) pyridine and bipyridine derivatives is reported. The key steps are Suzuki couplings of 4-pyridyl nonaflates with 4-acetyl-phenylboronic acid followed by an acid-promoted cyclocondensation reaction converting the methyl ketone moiety into the central benzene ring of the target compounds. Based on STM studies at a graphite-solution interface the two-dimensional arrangements of the compounds are discussed, showing the influence of the pyridine substitution pattern.
A three-component synthesis of β-alkoxy-β-keto-enamides—flexible precursors for 4-hydroxypyridine derivatives and their palladium-catalysed reactions
The flexible three-component reaction of lithiated alkoxyallenes with nitriles and carboxylic acids provided a series of highlyfunctionalised β-alkoxy-β-ketoenamide derivatives. Upon base induced cyclisation and conversion to 4-pyridyl nonaflates various palladium-catalysed coupling reactions could be employed. The efficacy of this approach to functionalised pyridine derivatives was demonstrated by
锂化烷氧基丙二烯与腈和羧酸的灵活三组分反应提供了一系列高度官能化的 β-烷氧基-β-酮烯酰胺衍生品。在碱诱导的环化和转化为4-吡啶基壬二酸酯时,各种钯-催化的偶联反应可被采用。这种方法对功能化的功效吡啶通过相当短的途径证明了其衍生物适合于Glenvastatin合成的关键中间体。在炔烃与4-吡啶基壬二酸酯的Sonogashira偶联之后,随后的环化导致高度荧光[2,3 c ]呋喃吡啶 衍生物,而Suzuki反应则提供了4-吡啶基对苯二甲酸酯,并且通过光环化反应得到了高度取代的 苯并异喹啉 衍生物。
Scope of a Novel Three-Component Synthesis of Highly Functionalized Pyridines
A mechanistically unique three-componentsynthesis provides a variety of functionalized pyridine derivatives in fair to excellent yields. The scope of this reaction was studied with respect to the alkoxyallene, the nitrile, and the carboxylic acid. Due to the 4-hydroxy group, these pyridine derivatives are suitable precursors for subsequent palladium-catalyzed reactions. Suzuki couplings of the corresponding