Complete regioselective addition of grignard reagents to pyrazine N-oxides, toward an efficient enantioselective synthesis of substituted piperazines
2010 (English)In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 12, no 2, 284-6 p.Article in journal (Refereed) Published
A conceptually new one-pot strategy for the synthesis of protected substituted piperazines via the addition of Grignard reagents to pyrazine N-oxides is presented. This strategy is high yielding (33-91% over three steps), step-efficient, and fast. The synthesized N,N-diprotected piperazines are convenient to handle and allow for orthogonal deprotection at either nitrogen for selective transformations. In addition, this is a synthetic route to enantiomerically enriched piperazines by using a combination of phenyl magnesium chloride and (-)-sparteine, which resulted in enantiomeric excesses up to 83%.
Place, publisher, year, edition, pages
American Chemical Society , 2010. Vol. 12, no 2, 284-6 p.
IdentifiersURN: urn:nbn:se:umu:diva-30813DOI: 10.1021/ol902619hISI: 000273428800021PubMedID: 20000607OAI: oai:DiVA.org:umu-30813DiVA: diva2:287216