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Intramolecular/Intermolecular Sequential Cyclization Accompanied by Double C-F Bond Cleavage: Access to Tricyclic
Dong-Sheng Yang1, Xiang-Long Chen1, Chun-Yan Wu1
1National Key Laboratory of Green Pesticide, International Joint Research Center for Intelligent Biosensor Technology and Health, College of Chemistry, Central China Normal University, Wuhan, Hubei 430079, China.
Abstract:
Defluorinative cyclization of CF3-alkenes has emerged as a reliable strategy for crafting intricate polycyclic frameworks. In this study, a facile defluorinative bicyclization approach was developed for the construction of 4H,5H-pyrano[3,2-c]chromenes under mild conditions involving a sequence of intramolecular cyclization and intermolecular defluoroheterocyclization. A variety of polysubstituted 4H,5H-pyrano[3,2-c]chromenes featuring C2-fluorine could be synthesized in good yields with excellent tolerance toward various functional groups. Moreover, the introduction of a C-F bond provides additional possibilities for further modification of this skeleton. The product features aggregation-induced emission (AIE) characteristics after simple modification, which is promising for chemical and biomedical imaging.
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