title: Reactions between Grignard reagents and heterocyclic N-oxides: stereoselective synthesis of substituted pyridines, piperidines, and piperazines.
abstract: In this perspective we discuss the recent developments of stereoselective synthesis of substituted pyridines, piperidines, and piperazines from cheap and commercially readily available starting materials. Pyridine N-oxides and pyrazine N-oxides are reacted with alkyl, aryl, alkynyl and vinyl Grignard reagents to give a diverse set of heterocycles in high yields. Optically active substituted piperazines are obtained by an asymmetric reaction from pyrazine N-oxides using sparteine as chiral ligand. In addition, a stereoselective synthesis of dienal-oximes from the reaction between pyridine N-oxides and Grignard reagents is presented, which results in a useful intermediate for the synthesis of a diverse set of compounds.
authors.affiliation: Umeå University, Department of Chemistry, Linnaeus väg, Umeå SE-90187, Sweden.
authors.forename: Hans
authors.initials: H
authors.lastname: Andersson
authors.forename: Roger
authors.initials: R
authors.lastname: Olsson
authors.forename: Fredrik
authors.initials: F
authors.lastname: Almqvist