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Asymmetric cyclopropanation of chalcones using chiral phase-transfer catalysts.

ABSTRACT: The first phase-transfer catalyzed cyclopropanation reaction of chalcones using bromomalonates as the nucleophiles in a Michael Initiated Ring Closing reaction (MIRC) was developed. Key to success was the use of a free OH-containing cinchona alkaloid ammonium salt catalyst and carefully optimized liquid/liquid reaction conditions. The reaction performed well for electron neutral and electron deficient chalcones giving the products in yields up to 98% and with enantiomeric ratios up to 91:9.

SUBMITTER: Herchl R

PROVIDER: S-EPMC3878557 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature

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Asymmetric cyclopropanation of chalcones using chiral phase-transfer catalysts.

Herchl Richard R Waser Mario M

Tetrahedron letters 20130501 20

The first phase-transfer catalyzed cyclopropanation reaction of chalcones using bromomalonates as the nucleophiles in a Michael Initiated Ring Closing reaction (MIRC) was developed. Key to success was the use of a free OH-containing cinchona alkaloid ammonium salt catalyst and carefully optimized liquid/liquid reaction conditions. The reaction performed well for electron neutral and electron deficient chalcones giving the products in yields up to 98% and with enantiomeric ratios up to 91:9. ...[more]

PMID: 24391288

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