Author: Karl W. Törnroos

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AUTHOR

Karl W. Törnroos

showing 6 related works from this author

Syntheses, crystal structures and magnetic properties of copper(II) polynuclear and dinuclear compounds with 2,3-bis(2-pyridyl)pyrazine (dpp) and pse…

2001

Abstract The preparation, crystal structures and magnetic properties of four heteroleptic copper(II) complexes with 2,3-bis(2-pyridyl)pyrazine (dpp) and azide, cyanate or thiocyanate as ligands are reported, [Cu(dpp)(N3)2]n (1), [Cu(dpp)(NCO)2]n (2), [Cu(dpp)(NCS)2]2 (3) and [Cu(H2O)(dpp)(NCS)2]2·2H2O (4). Compounds 1 and 2 are isomorphous, triclinic, space group P1, and consist of mononuclear building blocks featuring copper atoms with close to square planar coordination geometries. The mononuclear units are, however, associated into chains through weak axial Cu–N bonds formed by end-on asymmetrically bridging azido/cyanato groups and by pyridyl nitrogen atoms. Taking these contacts into a…

ThiocyanatePyrazineStereochemistrychemistry.chemical_elementCrystal structureTriclinic crystal systemCyanateCopperSquare pyramidal molecular geometryInorganic Chemistrychemistry.chemical_compoundCrystallographychemistryMaterials ChemistryMoleculePhysical and Theoretical ChemistryInorganica Chimica Acta

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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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Rare-earth metal bis(tetramethylaluminate) complexes supported by a sterically crowded triazenido ligand

2010

Complexes [NNN]Ln(AlMe(4))(2) (Ln = Y, La, Nd, Lu) bearing the sterically demanding aryl-substituted triazenido ligand [(Tph)(2)N(3)] (Tph = [2-(2,4,6-iPr(3)C(6)H(2))C(6)H(4)]) can be obtained from homoleptic complexes Ln(AlMe(4))(3) in moderate yields, both via protonolysis with [(Tph)(2)N(3)]H and a salt metathesis reaction pathway utilizing [(Tph)(2)N(3)]K. In the solid state the Y and Lu derivatives are isostructural, with both tetramethylaluminate groups coordinated in an eta(2) fashion, while one of the [AlMe(4)] ligands of the Nd derivative features a distorted eta(2) coordination mode. Due to the high affinity of the triazenido ligand toward the more Lewis-acidic and harder aluminiu…

Steric effectsChemistryLigandStereochemistryMedicinal chemistryInorganic ChemistryMetalchemistry.chemical_compoundvisual_artvisual_art.visual_art_mediumSalt metathesis reactionRedistribution (chemistry)ProtonolysisIsostructuralHomolepticDalton Transactions

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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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