Highly regioselective preparation of heteroaryl-magnesium reagents by using a Br/Mg exchange.
Disubstituted thienyl-, furyl- and pyridylmagnesium derivatives are regioselectively prepared from a Br/Mg exchange of the corresponding dibromo compounds by using either iPrMgCl⋅LiCl or hindered arylmagnesium reagents, such as isitylmagnesium bromide⋅lithium chloride (isityl = 2,4,6-triisopropyl-phenyl) complexed with a diamine ligand, in difficult cases. The selective functionalisations of these heterocyclic scaffolds by using Negishi cross-coupling reactions, acylations or addition to aldehydes were readily achieved.
Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377 München, Germany.
Christoph
C
Sämann
Benjamin
B
Haag
Paul
P
Knochel
D001965:Bromides / Q000737:chemistry*; D002384:Catalysis; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry*; D007477:Ions / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*; D015394:Molecular Structure; D013237:Stereoisomerism
D001965:Bromides; D006571:Heterocyclic Compounds; D007202:Indicators and Reagents; D007477:Ions; D008274:Magnesium