ansa-Vanadocene Complexes - Syntheses, Structures and Ligand Exchange Reactions

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Title:ansa-Vanadocene Complexes - Syntheses, Structures and Ligand Exchange Reactions
Creators:
Dorer, Birgit
Prosenc, Marc-Heinrich
Rief, Ursula
Brintzinger, Hans-Herbert
Journal or Publication Title:
Collection of Czechoslovak Chemical Communications, 62, 2, pp. 265-278
Uncontrolled Keywords:Vanadium, Chiral, <i>ansa</i>-Metallocenes, Acetylacetonato complex, Enantioseparation

Abstract

Tetramethylethano-bridged vanadocene dichlorides (CH<sub>3</sub>)<sub>4</sub>C<sub>2</sub>(3-R-C<sub>5</sub>H<sub>3</sub>)<sub>2</sub>VCl<sub>2</sub> with R = H, Me, <i>t</i>-Bu are obtained by reacting the corresponding ligand MgCl salts with vanadium(III) acetylacetonato compounds, followed by oxidation with PCl<sub>3</sub> or AgCl. Smooth ligand exchange reactions of these <i>ansa</i>-vanadocene dichlorides afford acetylacetonato cations and binaphtholate complexes; from these, the dichlorides are regenerated by exposure to MgCl<sub>2 </sub>in THF solution. Separation of <i>meso</i> and <i>rac</i> isomers (as well as enantiomer separation) is achieved <i>via</i> corresponding binaphtholate complexes; conversion to the vanadium(III) diisonitrile cations (CH<sub>3</sub>)<sub>4</sub>C<sub>2</sub>(3-R-C<sub>5</sub>H<sub>3</sub>)<sub>2</sub>V(CN<i>t</i>-Bu)<sub>2</sub><sup>+</sup> allows an assessment of diastereoisomer ratios by <sup>1</sup>H NMR. Lewis-acidic bistriflate derivatives of these <i>ansa</i>-vanadocene complexes are obtained from the dichlorides by reaction with silver triflate.

Title:ansa-Vanadocene Complexes - Syntheses, Structures and Ligand Exchange Reactions
Creators:
Dorer, Birgit
Prosenc, Marc-Heinrich
Rief, Ursula
Brintzinger, Hans-Herbert
Uncontrolled Keywords:Vanadium, Chiral, <i>ansa</i>-Metallocenes, Acetylacetonato complex, Enantioseparation
Divisions:Life and Chemical Sciences > Institute of Organic Chemistry and Biochemistry > Collection of Czechoslovak Chemical Communications
Journal or Publication Title:Collection of Czechoslovak Chemical Communications
Volume:62
Number:2
Page Range:pp. 265-278
ISSN:0010-0765
E-ISSN:1212-6950
Publisher:Institute of Organic Chemistry and Biochemistry
Related URLs:
URLURL Type
http://dx.doi.org/10.1135/cccc19970265UNSPECIFIED
ID Code:1113
Item Type:Article
Deposited On:06 Feb 2009 17:06
Last Modified:06 Feb 2009 16:06

Citation

Dorer, Birgit; Prosenc, Marc-Heinrich; Rief, Ursula; Brintzinger, Hans-Herbert (1997) ansa-Vanadocene Complexes - Syntheses, Structures and Ligand Exchange Reactions. Collection of Czechoslovak Chemical Communications, 62 (2). pp. 265-278. ISSN 0010-0765

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