title: Regioselective functionalization of trisubstituted pyridines using a bromine-magnesium exchange.
abstract: A tosyloxy substituent in position 2 allows a highly regioselective Br/Mg exchange reaction on 3,5-dibromopyridine derivatives using iso-PrMgCl.LiCl. The resulting functionalized pyridylmagnesium reagents react with various electrophiles in position 3. Acylated pyridines of this type can be readily converted into pyrazolo [3,4-b] pyridines.
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377, München, Germany.
authors.forename: Hongjun
authors.initials: H
authors.lastname: Ren
authors.forename: Paul
authors.initials: P
authors.lastname: Knochel