title: Synthesis of enones, pyrazolines and pyrrolines with gem-difluoroalkyl side chains.
abstract: Starting from easily accessible gem-difluoropropargylic derivatives, a DBU-mediated isomerisation affords enones in fair yields with a gem-difluoroalkyl chain. These derivatives were used to prepare pyrazolines and pyrrolines with the desired gem-difluoroalkyl side chain by cyclocondensations in good yields and with excellent stereoselectivity. A one-pot process was also successfully developed for these sequential reactions. By carrying out various types of Pd-catalyzed coupling reactions for compounds with a p-bromophenyl substituent a route to focused chemical libraries was demonstrated.
authors.affiliation: Université de Rennes 1, Institut des Sciences Chimiques de Rennes, CNRS UMR 6226, Avenue du Général Leclerc, 35042 Rennes Cedex, France ; Laboratory for Medicinal Chemistry and Natural Products, Lebanese University, Faculty of Sciences (1) and PRASE-EDST, Hadath, Beyrouth, Lebanon.
authors.forename: Assaad Nasr
authors.initials: AN
authors.lastname: El Dine
authors.forename: Ali
authors.initials: A
authors.lastname: Khalaf
authors.forename: Danielle
authors.initials: D
authors.lastname: Grée
authors.forename: Olivier
authors.initials: O
authors.lastname: Tasseau
authors.forename: Fares
authors.initials: F
authors.lastname: Fares
authors.forename: Nada
authors.initials: N
authors.lastname: Jaber
authors.forename: Philippe
authors.initials: P
authors.lastname: Lesot
authors.forename: Ali
authors.initials: A
authors.lastname: Hachem
authors.forename: René
authors.initials: R
authors.lastname: Grée
keywords: 19F/1H HOESY; gem-difluoroalkyl derivatives; organo-fluorine compounds; palladium catalysis; pyrazolines; pyrrolines