Rhodium and Ruthenium Complexes with Optically Active Chelate Cyclopentadienyl-Phosphine Bidentate Ligands

Kataoka, Yasutaka; Saito, Yoshinori; Nagata, Koji; Kitamura, Kenichi; Shibahara, Atsushi; Tani, Kazuhide

doi:10.1246/cl.1995.833

Cited by 26 publications

(16 citation statements)

References 13 publications

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“…Compared to the number of cyclopentadienyl chelate complexes with a phosphane tether known, the number of respective indenyl chelate complexes that have been reported is comparably small. Most of the known indenyl chelates with a phosphane tether are complexes of rhodium − and ruthenium. ,,, In addition some complexes of iridium and of chromium have been reported. Particularly interesting in this context are some results of Zargarian et al, who attempted the synthesis of indenyl nickel chelates.…”

Section: Introductionmentioning

confidence: 99%

The First η⁵-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether

et al. 2009

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The synthesis of the first indenylnickel chelate complexes with a pendant phosphane ligand is described. In contrast to earlier attempts by others directed to chelates with a tethered diphenylphosphino ligand in our hands, the synthesis was successful with a di-tert-butylphosphino ligand. The anionic ligand system was generated by a nucleophilic ring-opening of spiroindene 3 with lithium di-tert-butylphosphide, a reaction that was significantly accelerated by microwave irradiation. Alternatively, the borane-protected ligand was obtained by using the lithiated borane adduct of di-tert-butylphosphane. Reaction of the anionic ligand with nickel(II) chloride gave chloro chelate 8, which was transformed to azido, cyano, and isothiocyanato complexes 9−11, the cationic acetonitrile complex 12, and representatives containing nickel−carbon bonds, including the methyl and the ethynyl derivatives 13 and 18. A crystal structure analysis of methyl chelate 13 is also included. The 13C NMR data of a quarternized 2-pyridylethynyl derivative 20 suggest a significant contribution of the respective allenylidene resonance formulas 21 and 22. Finally, bimetallic ferrocenylethynyl complex 23 has been included as a bimetallic representative. Some of the complexes were characterized by cyclovoltammetry.

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Section: Introductionmentioning

confidence: 99%

The First η⁵-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether

et al. 2009

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“…The complexes were characterized spectroscopically. According to HMQC measurements 1 The syntheses as well as reactions of cyclopentadienyl or indenyl rhodium chelate complexes bearing a phosphane tether have been reported by Poilblanc et al, 50 Tani et al, [51][52][53][54][55][56] Nelson et al, 57,58 Saunders et al, [38][39][40][59][60][61] Hidai et al, 62 Jones et al, 63 Green et al, 64 Salzer et al, [65][66][67][68] Cole-Hamilton et al, 69 Lalinde et al, 70 and Whitby et al 71 In most cases the phosphane tether bears phenyl substituents, however, there are also some in which alkyl, pentafluorophenyl or more complicated substituents are present. To our knowledge there are no examples with tert-butyl substituents, which, according to our experience with cobalt complexes, increase the stability of the complexes and improve their crystallization properties.…”

Section: Resultsmentioning

confidence: 97%

New cyclopentadienylethylphosphane chelate complexes with unsymmetrical phosphane substitution

Janssen

Butenschön

2011

New J. Chem.

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The syntheses, characterization, and some reactions of (phosphanylethyl)cyclopentadienyl chelate complexes of cobalt, rhodium, iridium, nickel, and chromium with unsymmetrical substitution at the phosphorus atom are described. The ligand systems were prepared by nucleophilic ring opening of spiro[2.4]hepta-4,6-diene with lithium tert-butylphenylphosphide or lithium tert-butylcyclohexylphosphide. The anionic ligands give the respective chelate complexes by treatment with metal halide reagents. In three cases it was possible to obtain X-ray crystal structure analyses. The cobalt chelate complex undergoes oxidative addition with a dihydrosilane, the reaction results in the formation of products with three stereogenic centers at phosphorus, cobalt, and silicon, which show dynamic behavior as indicated by VTNMR. The rhodium chelate complex undergoes oxidative addition of iodomethane with diastereoselective formation of the respective Rh(III) chelate. While diastereoselectivity caused by a planar chiral indenyl ligand or by a stereogenic carbon center in the chelate backbone has earlier been observed, this is the first case of a stereoinduction by the stereogenic phosphorus ligand. Activation energies for the rotation of cobalt and rhodium chelates have also been determined by VTNMR.

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“…The observed diastereomer ratios ranged from 59+41 up to > 99+ < 1. In contrast to complexes 39-41, [26][27][28] where the chirality resides in the backbone of the structure and has to be transmitted to the metal centre by P-bonded aryl groups, the P coordinated Ru atom is closely located to the chiral donor group in the case of the phosphaferrocene derivatives 42 and 43, which leads to particularly high isomer ratios. 29 [Fig.…”

Section: Cp-ligands With Tethered Chiral Donor Groupsmentioning

confidence: 91%

Chiral organometallic half-sandwich complexes with defined metal configuration

Ganter

2003

Chem. Soc. Rev.

150

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Chiral organometallic half-sandwich complexes with stereogenic metal atoms are close relatives of chiral organic compounds with stereogenic carbon atoms. Similarities and differences between these two classes of compounds are outlined. Some representative metal complexes are discussed in an introductory section followed by a more detailed treatment of the available strategies to control the metal configuration by means of chiral auxiliaries. Special sections are devoted to the discussion of the configurational stability of chiral-at-metal complexes and their applications in stoichiometric and catalytic stereoselective reactions.

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Rhodium and Ruthenium Complexes with Optically Active Chelate Cyclopentadienyl-Phosphine Bidentate Ligands

Cited by 26 publications

References 13 publications

The First η⁵-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether

The First η⁵-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether

New cyclopentadienylethylphosphane chelate complexes with unsymmetrical phosphane substitution

Chiral organometallic half-sandwich complexes with defined metal configuration

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Rhodium and Ruthenium Complexes with Optically Active Chelate Cyclopentadienyl-Phosphine Bidentate Ligands

Cited by 26 publications

References 13 publications

The First η5-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether

The First η5-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether

New cyclopentadienylethylphosphane chelate complexes with unsymmetrical phosphane substitution

Chiral organometallic half-sandwich complexes with defined metal configuration

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The First η⁵-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether

The First η⁵-Indenylnickel Chelate Complexes with a Pendant Phosphane Tether