Efficient Synthesis of 4-Fluorocyclohexa-2,5-dienone Derivatives Using N-Fluoro-1,4-diazoniabicyclo[2.2.2]octane Salt Analogues
作者:Stojan Stavber、Marjan Jereb、Marko Zupan
DOI:10.1055/s-1999-2840
日期:1999.9
4-Fluorocyclohexa-2,5-dienone derivatives were obtained in high yield by reaction of para substituted phenols with 1-fluoro-4-chloromethyl-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoro-borate) (1a, SelectfluorTM F-TEDA-BF4) or its 4-hydroxy analogue (1b, AccufluorTM NFTh) in acetonitrile. Estrogen steroids were readily converted to 10β-fluoro-1,4-estradiene-3-one derivatives in high yields.
Efficient oxidative ipso-fluorination of para-substituted phenols using pyridinium polyhydrogen fluoride in combination with hypervalent iodine(III) reagents
4-fluorocyclohexa-2,5-dienones in a good yield. (R,S)-1,1′-Bi-5,6,7,8-tetrahydro-2-naphthol (and its monoacetate) yields atropoisomericfluorocyclohexadienones. The 4-substituted carbamate open-chain phenols were readily converted to fluorohydroindolenone and fluorohydroquinolenone derivatives by intramolecular conjugate addition.
Nucleophilic para-fluorination of 4-alkylphenols by hypervalent iodine reagent and pyridinium polyhydrogen fluoride (PPHF) a novel route to 4-fluorocyclohexa-2,5-dienones