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Merging [2+2] Cycloaddition with Radical 1,4‐Addition: Metal‐Free Access to Functionalized Cyclobuta[ a ]naphthalen‐4‐ols
Author(s) -
Liu Feng,
Wang JiaYin,
Zhou Peng,
Li Guigen,
Hao WenJuan,
Tu ShuJiang,
Jiang Bo
Publication year - 2017
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201707615
Subject(s) - cycloaddition , chemistry , allene , radical , dabco , tautomer , benzene , metal , combinatorial chemistry , photochemistry , medicinal chemistry , organic chemistry , octane , catalysis
A metal‐free [2+2] cycloaddition and 1,4‐addition sequence induced by S‐centered radicals has been achieved by treating benzene‐linked allene‐ynes with aryldiazonium tetrafluoroborates and DABCO‐bis(sulfur dioxide) in a one‐pot procedure. The reaction provides a greener and more practical access to functionalized cyclobuta[a]naphthalen‐4‐ols with valuable applications. More than 50 examples are demonstrated with excellent diastereoselectivity and chemical yields. The reaction pathway is proposed to proceed by the following steps:[2+2] cycloaddition, insertion of SO 2 , 1,4‐addition, diazotization, and tautomerization.