title: Selective mono- and 1,2-difunctionalisation of cyclopentene derivatives via Mg and Cu intermediates.
abstract: A single Br/Mg exchange of 1,2-dibromocyclopentene with iPrMgCl LiCl provides the corresponding beta-bromocyclopentenylmagnesium reagent, which can then be reacted with various electrophiles (yields: 65-82 %). In the presence of a secondary alkylmagnesium halide and Li2CuCl4 (2 mol %), these 2-bromoalkenylmagnesium compounds undergo bromine substitution and can then further react with electrophiles to give 1,2-difunctionalised cyclopentenes (63-79 %). The mechanism of this process is discussed.
authors.affiliation: Department Chemie und Biochemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377 München, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Despotopoulou
authors.forename: Richard C
authors.initials: RC
authors.lastname: Bauer
authors.forename: Arkady
authors.initials: A
authors.lastname: Krasovskiy
authors.forename: Peter
authors.initials: P
authors.lastname: Mayer
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Stryker
authors.forename: Paul
authors.initials: P
authors.lastname: Knochel