Author: Gert Callebaut

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AUTHOR

Gert Callebaut

showing 5 related works from this author

Asymmetric synthesis of α,β-diamino acid derivatives with an aziridine-, azetidine- and γ-lactone-skeleton via Mannich-type additions across α-chloro…

2012

The efficient asymmetric synthesis of new chiral γ-chloro-α,β-diamino acid derivatives via highly diastereoselective Mannich-type reactions of N-(diphenylmethylene) glycine esters across a chiral α-chloro-N-p-toluenesulfinylimine was developed. The influence of the base, LDA or LiHMDS, used for the formation of the glycine enolates, was of great importance for the anti-/syn-diastereoselectivity of the Mannich-type reaction. The γ-chloro-α,β-diamino acid derivatives proved to be excellent building blocks for ring closure towards optically pure anti- and syn-β,γ-aziridino-α-amino esters, and subsequent ring transformation into trans-3-aminoazetidine-2-carboxylic acid derivatives and α,β-diami…

Models MolecularStereochemistryAziridinesAzetidineDiamino acidRing (chemistry)BiochemistryLactoneschemistry.chemical_compoundBiosynthesisAmino AcidsPhysical and Theoretical Chemistryta116chemistry.chemical_classificationMolecular StructureSulfur CompoundsOrganic ChemistryEnantioselective synthesisStereoisomerismAziridinechemistryGlycineAzetidinesIminesChlorine CompoundsLactoneOrganic & Biomolecular Chemistry

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Asymmetric synthesis of chloroisothreonine derivatives via syn-stereoselective Mannich-type additions across N-sulfinyl-α- chloroimines

2014

Mannich-type reactions of O-Boc glycolic esters across chiral N-sulfinyl-α-chloroaldimines resulted in the efficient and syn-stereoselective synthesis of new γ-chloro-α-hydroxy-β-amino esters (dr > 99:1). The α-coordinating ability of the chlorine atom was of great importance for the diastereoselectivity of the Mannich-type reaction and overruled the chelation of the sulfinyl oxygen with the lithium ion of the incoming E-enolate in the transition state model. These novel chloroisothreonine derivatives proved to be excellent building blocks in asymmetric synthesis of novel syn-β,γ-aziridino-α-hydroxy esters and biologically relevant trans-oxazolidinone carboxylic esters.

Models MolecularThreonineState modelStereochemistryOrganic ChemistryChlorine atomEnantioselective synthesischemistry.chemical_elementEstersStereoisomerismCrystallography X-RayBiochemistryOxygenMannich BaseschemistryHydrocarbons ChlorinatedSide chainLithiumStereoselectivityChelationIminesPhysical and Theoretical Chemistryta116Organic and Biomolecular Chemistry

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CCDC 977961: Experimental Crystal Structure Determination

2014

Related Article: Gert Callebaut, Filip Colpaert, Melinda Nonn, Loránd Kiss, Reijo Sillanpää, Karl W. Törnroos, Ferenc Fülöp, Norbert De Kimpe, Sven Mangelinckx|2014|Org.Biomol.Chem.|12|3393|doi:10.1039/C4OB00243A

Space GroupCrystallographyCrystal System(R~S~2R2'S)-Ethyl 2-(t-butoxycarbonyloxy)-2-(1-t-butanesulfinylaziridin-2-yl)acetateCrystal StructureCell ParametersExperimental 3D Coordinates

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CCDC 977962: Experimental Crystal Structure Determination

2014

Space GroupCrystallographyCrystal SystemCrystal StructureCell Parameters(R~S~2R3R)-Ethyl 4-chloro-2-hydroxy-4-methyl-3-(t-butanesulfinylamino)pentanoateExperimental 3D Coordinates

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CCDC 977960: Experimental Crystal Structure Determination

2014

Space GroupCrystallographyCrystal SystemMethyl (S~S~2S3S)-2-((t-butoxycarbonyl)oxy)-4-chloro-4-methyl-3-(((4-methylphenyl)sulfinyl)amino)pentanoateCrystal StructureCell ParametersExperimental 3D Coordinates

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