Die Synthese von Derivaten des 3-Oxepins und des Furans durch eine zweifache Wittig-Reaktion

Direct Access to Trifluoromethylated Benzo[d]oxepines from o-Alkynylaryl Aldehydes and Trifluorodiazoethane

Reported in this Letter is a silver-catalyzed reaction between o-alkynylaryl aldehydes and trifluorodiazoethane that enables an expedient synthesis of trifluoromethylated benzo[d]oxepines. The reaction works through a silver-promoted 6-endo-dig cyclization of o-alkynylbenzaldehydes for the generation of an isochromenylium intermediate, which upon a ring-expansive addition of trifluorodiazoethane delivers a novel class of trifluoromethylated benzoxepine frameworks. This strategy was applied to the synthesis of phosphonylated benzo[d]oxepines using the Seyferth-Gilbert reagent.

Chemical Equivalent of Arene Monooxygenases: Dearomative Synthesis of Arene Oxides and Oxepines

Direct epoxidation of aromatic nuclei by cytochrome P450 monooxygenases is one of the major metabolic pathways of arenes in eukaryotes. The resulting arene oxides serve as versatile precursors to phenols, oxepines, or trans-dihydrodiol-based metabolites. Although such compounds have an important biological and chemical relevance, the lack of methods for their production has hampered access to their utility. Herein, we report a general arenophile-based strategy for the dearomative synthesis of arene oxides. The mildness of this method permits access to sensitive monocyclic arene oxides without any noticeable decomposition to phenols. Moreover, this method enables direct conversion of polycyclic arenes and heteroarenes into the corresponding oxepines. Finally, these studies provided direct connection between simple aromatic precursors and complex small organic molecules via arene oxides and oxepines.