Search results for "Quinolizidine"

showing 4 items of 4 documents

Organocatalytic enantioselective synthesis of quinolizidine alkaloids (+)-myrtine, (-)-lupinine, and (+)-epiepiquinamide

2011

The organocatalytic synthesis of quinolizidine alkaloids (+)-myrtine, (-)-lupinine, and (+)-epiepiquinamide is described. It involved, as the key step, an enantioselective intramolecular aza-Michael reaction (IMAMR) catalyzed by Jorgensen catalyst I, affording the common precursor with high enantioselectivity. This compound was subsequently transformed into the three alkaloids in a highly diastereoselective manner. (C) 2011 Elsevier Ltd. All rights reserved.

MyrtineLupinineQuinolizidineStereochemistryOrganocatalysisOrganic ChemistryEnantioselective synthesisEpiquinamideBiochemistryEpiquinamideCatalysischemistry.chemical_compoundLupininechemistryOrganocatalysisIntramolecular forceDrug DiscoveryOrganic chemistryQuinolizidine alkaloidsIntramolecular aza-Michael reaction
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Double asymmetric intramolecular aza-Michael reaction: a convenient strategy for the synthesis of quinolizidine alkaloids.

2021

A new methodology to access the quinolizidine skeleton in an asymmetric fashion was devised. It involves two consecutive intramolecular aza-Michael reactions of sulfinyl amines bearing a bis-enone moiety, in turn generated by a monodirectional cross metathesis reaction. The sequence, which takes place with excellent yields and diastereocontrol, was applied to the total synthesis of alkaloids lasubine I and myrtine.

Turn (biochemistry)chemistry.chemical_compoundQuinolizidineStereochemistryChemistryIntramolecular forceOrganic ChemistrySalt metathesis reactionMichael reactionTotal synthesisMoietyPhysical and Theoretical ChemistryBiochemistryOrganicbiomolecular chemistry
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ChemInform Abstract: Stereoselective Synthesis of Quinolizidine Alkaloids: (-)-Lasubin II.

2008

Initially, lasubin II was synthesized diastereoselectively in racemic form [3]. Asymmetric syntheses of lasubin II were achieved based on stereoselective transformations of enantiomerically pure substrates [4] or, for example, via a diastereoselective aza-Diels-Alder reaction using a resolved chiral arylaldehyde tricarbonylchromium complex [5]. Recently, an enantioselectively catalyzed aza-Diels-Alder reaction [6] and a [2+2+2] cycloaddition reaction [7] were successfully used for the synthesis of enantiomerically pure lasubin II.

chemistry.chemical_compoundLasubin IIQuinolizidinechemistryStereochemistryOrganic chemistryStereoselectivityGeneral MedicineCycloadditionCatalysisChemInform
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Stereoselective Synthesis of Quinolizidine Alkaloids: (–)-Lasubin II

2008

Initially, lasubin II was synthesized diastereoselectively in racemic form [3]. Asymmetric syntheses of lasubin II were achieved based on stereoselective transformations of enantiomerically pure substrates [4] or, for example, via a diastereoselective aza-Diels-Alder reaction using a resolved chiral arylaldehyde tricarbonylchromium complex [5]. Recently, an enantioselectively catalyzed aza-Diels-Alder reaction [6] and a [2+2+2] cycloaddition reaction [7] were successfully used for the synthesis of enantiomerically pure lasubin II.

chemistry.chemical_compoundLasubin IIQuinolizidinechemistryStereochemistryStereoselectivityGeneral ChemistryCycloadditionCatalysisZeitschrift für Naturforschung B
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