Enantioselective cyclopropanation reactions with planar-chiral pyridinium ylides: A substituent effect and a remote steric effect

Nobuhiro Kanomata, Ryo Sakaguchi, Kazuki Sekine, Satomi Yamashita, Hiroko Tanaka

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Novel planar-chiral pyridinium ylides were designed, and generated in situ from the corresponding pyridinium salts with triethylamine. Ylides with a common parapyridinophane skeleton reacted efficiently with electron-deficient dicyanoalkenes, or malononitriles, to produce optically active cyclopropane derivatives with high enantioselectivity (up to 99% ee). Remote steric effects were observed on the enantioselectivities, where the R2 groups of the pyridinophane core resulted in higher ee values of the products. Density function theory (DFT) calculations are in good agreement with our experimental results: the energetically favored transition state leads to the major stereoisomer, namely the trans-cyclopropane products.

Original languageEnglish
Pages (from-to)2966-2978
Number of pages13
JournalAdvanced Synthesis and Catalysis
Volume352
Issue number17
DOIs
Publication statusPublished - 2010 Nov 22

Keywords

  • cyclophanes
  • cyclopropanes
  • enantioselectivity
  • heterocycles
  • planar chirality
  • ylides

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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