One-pot organocatalytic domino michael/α-alkylation reactions: Direct catalytic enantioselective cyclopropanation and cyclopentanation reactions

Ismail Ibrahem, Gui Ling Zhao, Ramon Rios, Jan Vesely, Henrik Sundén, Pawel Dziedzic, Armando Córdova

Research output: Contribution to journalArticlepeer-review

147 Scopus citations

Abstract

The development of one-pot organocatalytic domino Michael/α- alkylation reactions between bromomalonates or bromoacetoacetate esters and α,β-unsaturated aldehydes is presented. The chiral-amine-catalyzed reactions with bromomalonates as substrates give access to the corresponding 2-formylcyclopropane derivatives in high yields with excellent diastereoselectivity and up to 99% ee. The catalytic domino Michael/α- alkylation reactions between 4-bromo-acetoacetate and enals provide a route for the synthesis of functionalized cyclopentanones in good to high yields with 93-99 % ee. The products from the organocatalytic reactions were also reduced with high diastereoselectivity to the corresponding cyclopropanols and cy-clopentanols, respectively. Moreover, one-pot combinations of amine and heterocyclic carbene catalysis (AHCC) enabled the highly enantioselective synthesis of β-malonate esters (91-97% ee) from the reaction between bromomalonates and enals. The tandem catalysis included the catalytic domino reaction followed by catalytic in situ chemoselective ring-opening of the 2-formylcyclopropane intermediates.

Original languageBritish English
Pages (from-to)7867-7879
Number of pages13
JournalChemistry - A European Journal
Volume14
Issue number26
DOIs
StatePublished - 8 Sep 2008

Keywords

  • Asymmetric catalysis
  • Cyclopentanes
  • Cyclopropanes
  • Domino reactions
  • Organocatalysis
  • Unsaturated aldehydes

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