Steroid imines as chiral ligands. Diastereoselective formation of (1-azadiene)Fe(CO)₃ complexes by sterically tuning the ligand coordination spheres
Tetrahedron : Asymmetry. Bd. 10. H. 15. Amsterdam: Elsevier 1999 S. 2983 - 2995
Erscheinungsjahr: 1999
ISBN/ISSN: 0957-4166
Publikationstyp: Zeitschriftenaufsatz
Sprache: Englisch
Doi/URN: 10.1016/S0957-4166(99)00281-5
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Inhaltszusammenfassung
The condensation of steroid amines with alpha,beta-unsaturated aldehydes leads to the formation of chiral 1-azadiene ligands with a steroid core attached to nitrogen. If the azadiene chain is situated at the D-ring of the steroid at C-16 or C-17, respectively, the two diastereotopic faces of the ligand may be discriminated by different neighbouring substituents and their configuration. The reaction of these ligands with Fe-2(CO)(9) produces mixtures of diastereomeric (1-azadiene)Fe(CO)(3) com...The condensation of steroid amines with alpha,beta-unsaturated aldehydes leads to the formation of chiral 1-azadiene ligands with a steroid core attached to nitrogen. If the azadiene chain is situated at the D-ring of the steroid at C-16 or C-17, respectively, the two diastereotopic faces of the ligand may be discriminated by different neighbouring substituents and their configuration. The reaction of these ligands with Fe-2(CO)(9) produces mixtures of diastereomeric (1-azadiene)Fe(CO)(3) complexes. By increasing the steric demands of the neighbouring groups it is possible to improve the diastereoselectivity of this complexation reaction from 1:1 mixtures using the least sterically hindered ligands to complete diastereoselectivity using the azadiene derived from cinnamaldehyde and 16 beta-amino-3-methoxy-estra-1,3,5(10)-triene-17 beta-ol. In addition, the molecular structure of [17 beta-(3-phenyl-prop-2-enyliden)-amino-3-methoxy-estra-1,3,5(10)-triene]Fe(CO)(3) was determined by X-ray structure analysis. (C) 1999 Elsevier Science Ltd. All rights reserved. » weiterlesen» einklappen