| Autor: |
Voloshin YZ; A. N. Nesmeyanov Institute of Organoelement Compounds of the Russian Academy of Sciences, 119991, Moscow, Russian Federation. voloshin@ineos.ac.ru, Belov AS, Varzatskii OA, Shul'ga SV, Stuzhin PA, Starikova ZA, Lebed EG, Bubnov YN |
| Jazyk: |
angličtina |
| Zdroj: |
Dalton transactions (Cambridge, England : 2003) [Dalton Trans] 2012 Jan 21; Vol. 41 (3), pp. 921-8. Date of Electronic Publication: 2011 Nov 16. |
| DOI: |
10.1039/c1dt11285f |
| Abstrakt: |
Monoribbed-substituted mono- and dicyano-functionalized iron(II) macrobicycles were obtained for the first time by the reaction of iron(II) diiodoclathrochelate precursor with copper(I) cyanide-triphenylphosphine complex under mild conditions. The target dinitrile clathrochelate is a minor product of this reaction, whereas the major product contains only one cyano group. The clathrochelates obtained were characterized using elemental analysis, (1)H and (13)C{(1)H} NMR, IR and UV-vis spectroscopy, MALDI-TOF spectrometry and X-ray diffraction crystallography. The geometry of their FeN(6)-coordination polyhedra is intermediate between a trigonal prism (TP) and a trigonal antiprism (TAP); the distortion angles, φ, are 22.6-24.7°. In the molecule of the precursor, the Fe-N distances are close, whereas in the mononitrile macrobicycles those for their functionalized chelate fragments are substantially smaller than the corresponding distances in the α-benzyldioximate moieties. The heights, h, of the TP-TAP coordination polyhedra and the average bite angles, α, (2.33 Å and 39°, respectively) are the same for the X-rayed clathrochelates. The UV-vis spectra indicate a dramatic redistribution of the electron density in the π-conjugated clathrochelate framework caused by functionalization with inherent nitrile substituents. The proposed mechanism of the dehalogenation-reduction reaction of iron(II) diiodoclathrochelate resulting in substitution of their iodine atoms by a cyano group and hydrogen atom includes the anion-radical hydrodehalogenation of this precursor with acetonitrile as a source of hydrogen atom. Then, the monomethinemonoiodine macrobicyclic product underwent a substitution with a cyano group only. The copper(I) cyanide-triphenylphosphine-acetonitrile system is proposed as a tool for the synthesis of nitrile derivatives of electron-withdrawing heterocycles starting from their halogen-containing precursors. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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