Novel Silver Tetrafluoroborate Catalyzed Electrophilic Cascade Cyclization Reaction: A Facile Approach to the Synthesis of Halo-Substituted Benzo[a]fluorenols
摘要:
A facile and novel silver tetrafluoroborate catalyzed electrophilic cascade cyclization reaction to generate halo-substituted benzo[a]fluorenols under mild conditions is disclosed. Good chemical selectivity and mild reaction conditions were involved in the transformation. The halide-containing benzo[a]fluorenols could be further elaborated via palladium-catalyzed cross-coupling reactions to introduce complexity.
本文中,通过芳基稠合的1,6-二炔-3-酮的位点选择性分子内环化,已经证明了一种容易的以多样性为导向的方法来接近官能化的苯并[ a ]芴,苯并[ b ]芴酮和萘基酮。分别使用TfOH和AgBF 4分别通过原位形成的缩醛选择性地完成了苯并[ a ]芴和萘基酮的合成。芳基稠合的1,6-二炔-3-酮经历三氟甲磺酸-介导的分子内环化,从而导致苯并[ b ]芴酮衍生物通过EPR研究支持的基本中间体。还通过紫外可见光谱分析对这些转变进行了动力学研究,以阐明反应概况。