Construction of Substituted Benzene Rings by Palladium-Catalyzed Direct Cross-Coupling of Olefins: A Rapid Synthetic Route to 1,4-Naphthoquinone and Its Derivatives
作者:Peng Hu、Shijun Huang、Jing Xu、Zhang-Jie Shi、Weiping Su
DOI:10.1002/anie.201103380
日期:2011.10.10
the changes: The direct cross‐coupling of electron‐deficient 1,4‐benzoquinone or itsderivatives with electron‐rich alkyl vinyl ethers proceeds in a tandem manner to produce substituted benzene rings with good selectivity and in good to excellent yields (see scheme). The reaction has the potential for the rapid synthesis of diverse substituted benzene rings as it is not limited by substituent effects
Solar photochemistry: optimisation of the photo Friedel–Crafts acylation of naphthoquinones
作者:Lorna J. Mitchell、William Lewis、Christopher J. Moody
DOI:10.1039/c3gc41477a
日期:——
A practical and robust photo FriedelâCrafts acylation of naphthoquinones is described. Although the reaction proceeds slowly in sunlight, the optimised conditions offer a substantial improvement to those already reported, by the utilisation of a more reliable and practical âsun-mimickingâ light source, a less hazardous solvent system (trifluorotoluene) and faster reaction times. Using these conditions, the reaction scope has been expanded to include functionalised aldehyde and naphthoquinone substrates, affording the desired photo-products in acceptable to excellent yields (17â81%). Factors influencing the regiochemistry of the photo FriedelâCrafts reaction on unsymmetrical naphthoquinones have also been investigated.
Studies on the syntheses of tetracycline derivatives. II. Thermolytic cycloaddition of o-quinodimethanes with tetrahydronaphthoquinone and naphthoquinone.
Tetrahydronaphthoquinone (8) and naphthoquinone reacted with the o-quinodimethanes, generated in situ from the benzocyclobutenes (7) and (14), to give the naphthacene-5, 12-quinone derivatives (9, 15 and 25).