Asymmetric carbon-carbon bond formations in conjugate additions of lithiated N-Boc allylic and benzylic amines to nitroalkenes: Enantioselective synthesis of substituted piperidines, pyrrolidines, and pyrimidinones

Timothy A. Johnson, Doo Ok Jang, Brian W. Slafer, Michael D. Curtis, Peter Beak

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(-)-Sparteine mediated lithiations of N-Boc-allylic and benzylic amines provide configurationally stable intermediates which on conjugate additions to nitroalkenes provide highly enantioenriched enecarbamate products in good yields, and with high diastereoselectivities. Straightforward transformations of these adducts offer general routes to substituted 3,4-substituted piperidines, 3,4-substituted pyrrolidines, and 4,5-substituted pyrimidinones. Diastereoselective substitutions of intermediate lactams followed by reduction provide 3,4,5-substituted piperidines and 3,4-trisubstituted pyrrolidines. Lithiation adjacent to nitrogen of 3,4-substituted piperidines and pyrrolidines followed by diastereoselective substitution opens a route to 2,4,5- and 2,4,5,6-substituted piperidines as well as 2,3,4- and 2,3,4,5-substituted pyrrolidines. The enantiomers of the enecarbamate and 3,4-substituted piperidine products may be accessed by stannylation/transmetalation sequences as well as by further manipulation of 4-substituted piperidones. The methodology is used to synthesize both enantiomers of an aspartic peptidase inhibitor intermediate, 3-hydroxy-4-phenylpiperidine, as well as the antidepressant (+)-femoxetine.

Original languageEnglish
Pages (from-to)11689-11698
Number of pages10
JournalJournal of the American Chemical Society
Issue number39
Publication statusPublished - 2002 Oct 2


All Science Journal Classification (ASJC) codes

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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