title: Chemoselective reduction of quinols as an alternative to Sonogashira coupling: synthesis of polysubstituted benzofurans.
abstract: An efficient synthetic approach to polysubstituted benzofurans is described, using 2-methoxyquinone as a benzofuran backbone. Nucleophilic addition of terminal alkynes to 2-methoxy-1,4-benzoquinone afforded the corresponding quinols containing an alkyne unit, which were converted to phenols via mild Zn-mediated reduction. After proper protection of the free phenolic OH, 5-endo-dig iodocyclization allowed facile access to a number of 3-iodobenzofurans. In addition, it was demonstrated for the first time that o-methoxyarylalkynes underwent intramolecular hydroalkoxylation under the influence of AgOTf furnishing the corresponding benzofurans.
authors.affiliation: College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon, 21983, Republic of Korea. ikyonkim@yonsei.ac.kr.
authors.forename: Youngeun
authors.initials: Y
authors.lastname: Jung
authors.affiliation: College of Pharmacy and Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon, 21983, Republic of Korea. ikyonkim@yonsei.ac.kr.
authors.forename: Ikyon
authors.initials: I
authors.lastname: Kim