Copper‐Catalyzed One‐Pot Synthesis of Dibenzofurans, Xanthenes, and Xanthones from Cyclic Diphenyl Iodoniums

Abstract

Oxygenation of cyclic diphenyl iodoniums (CDPIs) with varied medium‐ring sizes has been fully investigated. This practical copper‐catalyzed tandem reaction of CDPIs with water as the oxygen source enables the construction of derivatised dibenzofurans and xanthenes at moderate to good yields. Moreover, structurally important xanthones are also successfully accessed under the oxygenation conditions with additional TEMPO.

Synthesis of Tribenzo[b,d,f]azepines via Cascade π-Extended Decarboxylative Annulation Involving Cyclic Diaryliodonium Salts

“…Furthermore, to the best of our knowledge, currently it can only be employed for the construction of five or six-membered all-carbon aromatic ring. Recently, with diverse benzoic acid and cyclic diaryliodonium salt − as the starting materials, we reported the one-step synthesis of triphenylenes and dibenzo­[ f , h ]­quinolines via a π-extended decarboxylative annulation (PEDA) strategy . In continuation of our research interest in development of novel methodologies for heterocycle synthesis, we demonstrate that this PEDA strategy can be employed not only for the construction of six-membered all carbon aromatic ring but also for the seven-membered nitrogen containing heterocycle formation.…”

Six-membered ring systems: with O and/or S atoms

“…Structurally diverse xanthenes can be prepared by a copper(II)-mediated cyclization of cyclic diaryl iodoniums using sodium carbonate and 1,2-glycol in a mixture of 5% water/DMF, under argon atmosphere. Moreover, the addition of TEMPO led to the synthesis of xanthen-9-ones (Scheme 79) (19EJO4566). A wide range of polysubstituted 9H-xanthen-9-ones were prepared via cross-dehydrogenative intramolecular Scheme 77 Scheme 78 coupling reactions of 2-aryloxybenzaldehydes, under dual catalysis of copper powder and Selectfluor in acetonitrile (19T130533).…”

One-Pot Synthesis and Conformational Analysis of Six-Membered Cyclic Iodonium Salts

“…The analytical data is in accordance with literature data. [22] 2-(Trifluoromethyl)-10H-dibenzo[b,e]iodinin-5-ium trifluoromethanesulfonate (7e)…”