6533b86efe1ef96bd12cb553
RESEARCH PRODUCT
Asymmetric, Three-Component, One-Pot Synthesis of Spiropyrazolones and 2,5-Chromenediones from Aldol Condensation/NHC-Catalyzed Annulation Reactions
Daniel HackKari RissanenPankaj ChauhanDieter EndersArne R. PhilippsLei WangRakesh PuttreddySun LiGerhard Raabesubject
Annulationsynthesis010405 organic chemistryChemistryspiropyrazolonesOrganic ChemistryOne-pot synthesisEnantioselective synthesisGeneral Chemistry010402 general chemistry01 natural sciencesCatalysis0104 chemical sciencesCatalysischemistry.chemical_compoundOrganic chemistryPyrazolonesAldol condensationta116Carbenedescription
A novel one-pot, three-component diastereo- and enantioselective synthesis of spiropyrazolones has been developed involving the aldol condensation of an enal to generate α,β-unsaturated pyrazolones, which react with a second equivalent of enal through an N-heterocyclic carbene (NHC)-catalyzed [3+2] annulation. The desired spirocyclopentane pyrazolones are obtained in moderate to good yields and good to excellent stereoselectivities. Alternatively, starting from cyclic 1,3-diketones, 2,5-chromenediones are available through [2+4] annulation.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-02-18 | Chemistry - A European Journal |