Enantioselective Synthesis of Spirorhodanine-Pyran Derivatives via Organocatalytic [3 + 3] Annulation Reactions between Pyrazolones and Rhodanine-Derived Ketoesters
Dongsheng Ji, Yong‐Chun Luo, Xiu‐Qin Hu, Peng‐Fei Xu
Abstract
A series of novel biselectrophilic β,γ-unsaturated α-ketoesters were designed and synthesized from rhodanine. Under the catalysis of chiral squaramides, the enantioselective [3 + 3] annulation reaction of these novel ketoesters with pyrazolones was developed. This reaction offers an efficient method for the synthesis of chiral 2′-thioxo-5,6-dihydrospiro[pyrano[2,3-c]pyrazole-4,5′-thiazolidin]-4′-ones.
Topics & Concepts
PyrazolonesRhodanineChemistryEnantioselective synthesisPyranAnnulationSquaramideOrganocatalysisCatalysisCombinatorial chemistryOrganic chemistryAsymmetric Synthesis and CatalysisChemical synthesis and alkaloidsSynthetic Organic Chemistry Methods