Sulfonic Acid-Catalyzed Autoxidative Carbon-Carbon Coupling Reaction under Elevated Partial Pressure of Oxygen
作者:Áron Pintér、Martin Klussmann
DOI:10.1002/adsc.201100563
日期:2012.3
reactivity at ambient pressure. The benzylicCHbonds of xanthene, acridanes, isochromane and related heterocycles could be functionalized with nucleophiles including ketones, 1,3‐dicarbonyl compounds and aldehydes. Electron‐rich arenes could be utilized as nucleophiles at elevated temperatures. The reactions are believed to proceed via autoxidation of the benzylicCHbonds to the hydroperoxides and subsequent
Oxidation of xanthenes with manganese(III) acetate in the presence of active methylene compounds such as 1,3-dicarbonyl compounds, malononitrile derivatives, acetone, and nitromethane selectively gives 9-substituted xanthene derivatives in good yields. A similar oxidation of thioxanthene also yields 2-(9-thioxanthenyl)-1,3-dicarbonyl compounds in 57-91% yields. The obtained 2-(9-xanthenyl)-1,3-dicarbonyl compounds are readily converted to 2-(9-xanthenylidene)-1,3-dicarbonyl derivatives using manganese(III) complexes or 2,3-dichloro-5, 6-dicyano-1,4-benzoquinone. The mechanisms for the formation of 9-substituted xanthenes are discussed on the basis of the reaction of intermediates, the electron-donating substituent effect on the xanthene ring system, effect of additives, and comparison with a reaction of radical-trapping reagents.
Fosse, Bulletin de la Societe Chimique de France, 1906, vol. <3> 35, p. 1005
作者:Fosse
DOI:——
日期:——
Fosse; Robyn, Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1906, vol. 143, p. 240,241
作者:Fosse、Robyn
DOI:——
日期:——
Electrochemical dehydrogenative cross-coupling of xanthenes with ketones
作者:Yong-Zheng Yang、Yan-Chen Wu、Ren-Jie Song、Jin-Heng Li
DOI:10.1039/d0cc02580a
日期:——
functionalized 9-alkyl-9H-xanthenes was developed. This method enables the formation of a new C(sp3)–C(sp3) bond through release of H2 as the major byproduct at room temperature, and features mild conditions, high atom economy, excellent functional-group tolerance, scalability and facile applications in pharmaceutical chemistry.