The preparation of azulene-substituted benzofurans and isocoumarins was established by two types of intramolecular cyclization reaction of 1-ethynylazulenes. 2-(1-Azulenyl)- and 2,3-bis(1-azulenyl)benzofurans were prepared by the palladium-catalyzed cross-coupling reaction of 1-iodoazulenes with 2-ethynylphenol and that of 1-ethynylazulenes with 2-iodophenol under Sonogashira–Hagihara reaction conditions following the intramolecular nucleophilic addition of the oxygen nucleophile to the presumed 1-arylethynylazulenes. In contrast, 1-(phenylethynyl)azulenes bearing an o-methoxycarbonyl function on the substituted phenyl moiety exhibited intramolecular cyclization either in the presence of trifluoroacetic acid or N-iodosuccinimide (NIS) to afford azulene-substituted isocoumarins and 4-iodoisocoumarins, and the structures were clarified by single-crystal X-ray analysis. The optical properties of these compounds were also investigated by UV/vis spectroscopy and theoretical calculations.

中文翻译：

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通过1-乙炔 基azulenes的分子内环化合成氮杂取代的苯并呋喃和异香豆素及其结构和光学性质†

通过两种类型的1-乙炔基azulenes分子内环化反应，建立了氮杂取代苯并呋喃和异香豆素的制备方法。通过1-碘咪唑与2-乙炔基苯酚和1-乙炔基azulenes与2-碘苯酚的钯催化交叉偶联反应，制备了2-（1-氮杂烯基）-和2,3-双（1-氮杂烯基）苯并呋喃。分子内亲核加氧亲核试剂到假定的1-芳基乙炔基azulenes之后，Sonogashira–Hagihara反应条件。相反，在三氟乙酸或N的存在下，在取代的苯基部分上带有邻甲氧基羰基官能团的1-（苯基乙炔基）azulenes显示出分子内环化。-碘代琥珀酰亚胺（NIS），得到氮杂取代的异香豆素和4-碘异香豆素，并且通过单晶X射线分析澄清了结构。还通过紫外/可见光谱和理论计算研究了这些化合物的光学性质。