1242081-10-2Relevant academic research and scientific papers
Synthesis of 7-Allylated Benzofuran Derivatives from o-Allyloxyethynylbenzene via Claisen Rearrangement and TBAF-Catalyzed Annulation
Watanabe, Kohei,Mino, Takashi,Masuda, Chihiro,Yoshida, Yasushi,Sakamoto, Masami
, p. 1635 - 1645 (2019)
The 7-allylated benzofuran derivatives were synthesized via a continuous reaction of Claisen rearrangement and annulation using o-allyloxyetynylbenzene as starting material. In addition, it was observed that annulation of o-alkynylphenol proceeded under mild conditions when carried out in the presence of a catalytic amount of TBAF. Furthermore, these continuous reactions could be achieved in a one-pot reaction and afforded not only 7-allylbenzofurans but also 7-alkenylbenzofurans by controlling the reaction temperature and time of the annulation. Finally, we demonstrated that 7-allylbenzofuran and 7-alkenylbenzofuran could be converted into 7-(2-formylvinyl)benzofuran and 7-formylbenzofuran derivatives, respectively. Therefore, various 7-substituted benzofuran derivatives could be synthesized according to this synthetic strategy.
