Organocatalytic enantioselective decarboxylative Michael addition of β-ketoacids to α,β-unsaturated ketones
作者:Young Ku Kang、Hyun Joo Lee、Hyoung Wook Moon、Dae Young Kim
DOI:10.1039/c2ra21945j
日期:——
EnantioselectivedecarboxylativeMichaeladdition reactions promoted by chiral primary amine organocatalysts have been developed, allowing the facile synthesis of the corresponding chiral 1,5-diketones with excellent enantioselectivity (up to 97% ee). The method reported represents a valuable approach of utilizing β-ketoacids as synthetic equivalents of aryl methyl ketones.
Primary β-Amino Acid Salt-catalyzed Asymmetric Michael Addition of Benzoylacetates to Cyclic Enones and Its Application for the Synthesis of Enantioenriched 1,5-Diketones
作者:Masanori Yoshida、Ami Kubara、Shoji Hara
DOI:10.1246/cl.2013.180
日期:2013.2.5
The asymmetric Michael addition of benzoylacetates to cyclic enones was successfully carried out by using a primary β-amino acid salt catalyst. The reactions proceeded under mild reaction conditions to produce Michael adducts in high yields and with high enantioselectivities. The obtained Michael adducts were converted into β-benzoylmethylated cyclic ketones by decarboxylation without a significant loss of enantiomeric excess.
4-Chloro-2-fluoro-5-nitrobenzoic acid is a commercially available multireactive buildingblock that can serve as a starting material in heterocyclic oriented synthesis (HOS) leading to various condensed nitrogenous cycles. This work describes its ability for the preparation of substituted nitrogenous heterocycles having 5–7-membered cycles via polymer-supported o-phenylendiamines. Immobilization of