Complete regioselective addition of grignard reagents to pyrazine N-oxides, toward an efficient enantioselective synthesis of substituted piperazines

Research output: Contribution to journalArticle


(Figure presented) 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%.


  • Hans Andersson
  • Thomas Sainte Luce Banchelin
  • Sajal Das
  • Magnus Gustafsson
  • Roger Olsson
  • Fredrik Almqvist
External organisations
  • Umeå University
  • ACADIA Pharmaceuticals AB
  • University of Gothenburg
Original languageEnglish
Pages (from-to)284-286
Number of pages3
JournalOrganic Letters
Issue number2
Publication statusPublished - 2010 Jan 15
Publication categoryResearch
Externally publishedYes