title: Regio- and chemoselective bromination of 2,3-diarylcyclopent-2-en-1-ones.
abstract: The bromination of 2,3-diarylcyclopent-2-en-1-ones under various conditions has been studied. It was found that depending on the brominating reagent and nature of solvent the bromine atom can be introduced at the 4- or 5-position of the ethene "bridge", as well as into the aryl moieties. Aryl group bromination is accomplished with such reagents as molecular bromine, N-bromosuccinimide, or tetrabutylammonium tribromide. 5-Bromocyclopentenones with very high efficiency can be obtained by the reaction with copper(II) bromide in methanol, while 4-bromoketones are prepared in n-propyl acetate. The developed methods can be highly useful for the synthesis of bromo-substituted 2-cyclopenten-1-ones and their close analogues, which are important synthons in organic synthesis and for the preparation of a variety of useful substances.
authors.affiliation: N.D. Zelinsky Institute of Organic Chemistry RAS, 47 Leninsky prosp., 119991 Moscow, Russian Federation. shir@ioc.ac.ru
authors.forename: Valerii Z
authors.initials: VZ
authors.lastname: Shirinian
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Lonshakov
authors.forename: Vadim V
authors.initials: VV
authors.lastname: Kachala
authors.forename: Igor V
authors.initials: IV
authors.lastname: Zavarzin
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Shimkin
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Lvov
authors.forename: Mikhail M
authors.initials: MM
authors.lastname: Krayushkin