A heteronuclear .mu.-alkyne complex, [.mu.-(CF3)2C2]CoMo(CO)5(.eta.-C5H5)

Jensen, S.; Robinson, Brian H.; Simpson, Jim

doi:10.1021/om00139a029

Cited by 43 publications

(8 citation statements)

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“…A check of the Cambridge Structural Database reveals that 5 represents the first crystallographically characterized benzylidyne-bridged CoMo dinuclear compound. The Co(1)-Mo(1) bond distance of 2.789(1) Å agrees well with those Co-Mo distances in simple ligand-bridged dinuclear compounds [28] and CoMo polynuclear clusters [9,11,22,21,29]. The Co(1)-C(39) and Mo(1)-C(39) bond distances of 1.974 (6) and 1.856(6) Å , respectively, and the 93.4(3)°for the Co(1)-C(39)-Mo(1) atoms are consistent with bridging of the Co-Mo bond by the benzylidyne moiety.…”

Section: 2supporting

confidence: 75%

Ligand substitution in the tetrahedrane clusters RCCo2Mo(η5-indenyl)(CO)8 with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd): Influence of the carbyne and indenyl ligands on the stability of the substitution products and X-ray diffraction structures of HCCo2Mo(η5-indenyl)(CO)6(μ-bpcd) and CoMo(η5-indenyl)(μ-CPh)(CO)2(μ-bpcd)Cl

Watson¹,

Poola²,

Richmond³

2006

Journal of Organometallic Chemistry

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Section: 2supporting

confidence: 75%

Ligand substitution in the tetrahedrane clusters RCCo2Mo(η5-indenyl)(CO)8 with 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd): Influence of the carbyne and indenyl ligands on the stability of the substitution products and X-ray diffraction structures of HCCo2Mo(η5-indenyl)(CO)6(μ-bpcd) and CoMo(η5-indenyl)(μ-CPh)(CO)2(μ-bpcd)Cl

Watson¹,

Poola²,

Richmond³

2006

Journal of Organometallic Chemistry

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“…All complexes show a large number of strong terminal carbonyl absorption bands located at 2093−1878 cm -1 in the IR spectra, whereas in the IR spectra of 4 − 6 , besides the terminal carbonyl absorption bands, there are absorption bands in the region 1821−1849 cm -1 characteristic of semibridging carbonyls. The absorption of carbonyl ligands coordinated to Co atoms occurs at higher wavenumbers than those coordinated to Mo atoms. , The 1 H NMR spectra of all clusters show the presence of hydrogen atoms in their corresponding organic groups. For the substituted cyclopentadienyl rings, the 1 H NMR spectra of b and c exhibit four asymmetric singlets in the range δ 5.99−5.28 instead of two groups of triplets (A 2 B 2 type), comprising two upfield singlets assignable to the two protons at the 3,4-positions of the substituted cyclopentadienyl rings and two downfield singlets assignable to the 2,5-protons, resulting from the different deshielding effects of electron-withdrawing groups COCH 3 and COOC 2 H 5 on these nuclei. , However, the protons of unsubstituted cyclopentadienyl appear as a singlet in the range δ 5.39−5.27.…”

Section: Resultsmentioning

confidence: 92%

Reactions of 1,8-Nonadiyne with Co₂(CO)₈ and Mo₂(C₅H₄R)₂(CO)₄ and Crystal Structures of [M₂L₂(CO)₄][μ-HC₂(CH₂)₅C₂H-μ][Mo₂(C₅H₄R)₂(CO)₄] (M = Co, L = CO; M = Mo, L = C₅H₄R, R = H, COCH₃, COOC₂H₅)

et al. 1999

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Reaction of [{M(r/5-CsHs)(/z-CI)}2{/z-(~5-CsH4-'05-C5H4)}] (M = Ti, 1; Zr, 2) or [{M(r/5-C5H5)C1E}2{/z-(r/5-C5H4-r/5-CsH4)}], (M = Ti, 5; Zr, 6) with one or two equivalents of LiPPh 2 afforded the new phosphanidometal(III) complexes [{M(C5Hs)(/x-PPhE)}Z{/.~-(r/5-CsH4-~/5-CsH4)}], (M = Ti, 3; Zr, 4). Reaction of 2 with Li~'-CSiMe 3 led to the diamagnetic zirconium(III) alkynyl derivative [{Zr(C5Hs)(/~-C~-CSiMea)}E(/X-r/5-CsH4-r/5-CsH4] , 7. Alkylation of 6 with LiCH2CMe2Ph gave [{Zr(r/5-CsHs)(CHECMeEPh)E}E{/Z-('05-CsH4-r/5-CsH4)}], 8. A detailed NMR study of complexes 3 and 4 allowed the observation of the spectral behaviour of the eight different fulvalene protons through their coupling to the 31p nucleus. The fluxional behaviour of complex 7 was studied by dynamic DNMR, and kinetic parameters for the tr-Tr-conversion of the alkynyl iigand were determined. The molecular structures of complexes 3 and 7 were determined by X-ray diffraction methods.

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“…These coupling reactions are intramolecular arene-alkyne coupling, [352,353] the Friedel-Crafts alkenylations of arenes, [354] the heteroarylations of alkynes, [355,356] and the isomerizations of an α-arylprogargl alcohol, [357,358] etc. [359] For example, platinium-catalyzed coupling reaction of arene-alkyne proceed via intramolecular electrophilic hydroarylation as shown in eqn (38). [353]…”

Section: Coupling Reactions With Iminesmentioning

confidence: 99%

Three characteristic reactions of alkynes with metal compounds in organic synthesis

Omae

2008

Applied Organom Chemis

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IntroductionBoth alkynes and alkenes are compounds having at least one π -electron bond. Therefore, in these compounds, reactions such as the addition of hydrogen, the addition of halogens, the addition of hydrogen halides, metathesis, oxidation and polymerization, proceed in the presence of metal compounds.However, alkynes have another set of π -electron bonds. These two sets of π -electron bonds in alkynes are mutually orthogonal. Hence, the reactions of alkynes in the presence of the metal compounds are different from the reactions of alkenes.As described in the next section, the two sets of mutually orthogonal π -electron bonds tend to easily bond with d-electrons in transition metals. Consequently, the characteristic reactions of alkynes occur in the presence of the transition metals. In these transition metal compounds, especially, a Co-Co bond in (CO) 4 Co-Co(CO) 4 , very easily form a mutually bridged bond with the two sets of π -electron bonds in alkynes. These reactions of alkynes with alkenes in the presence of Co 2 (CO) 8 are the most characteristic reactions of alkynes with the transition metals in organic synthesis.This first type of characteristic reaction of alkynes with organocobalt compounds is the Pauson-Khand reactions. Reactions that are similar to the Pauson-Khand reactions, Pauson-Khand-type reactions, occur in the presence of the other transition metal compounds besides the cobalt carbonyl compounds, and also proceed as the first type of characteristic reactions. The Pauson-Khand reactions and Pauson-Khand-type reactions are the reactions of alkynes, alkenes and carbon monoxide. In these three components, alkynes and carbon monoxide have two sets of π -electron bonds and alkenes have one set of π -electron bond. These reactions are also called as the [2 + 2 + 1] cyclizations.The second type of characteristic reactions of alkynes with the transition metal compounds is other cyclizations in which alkynes react with compounds having π -electron bonds such as other alkynes, alkenes, allenes, aldehydes, ketones, imines, carbon monoxide, carbon dioxide and nitriles. These reactions are cyclooligomerizations and cycloadditions.The third type of characteristic reaction of alkynes in the presence of the metal compounds is coupling reactions in which the negative charge of the carbon atom in alkynes is involved in addition to the high reactivity to the π -electron bond. The reactions are carbonylations, dioxycarbonylations, coupling reactions with aldehydes, ketones, imines, alkenes, allyl compounds, alkynes, other oxygen-containing compounds or nitrogen-containing compounds, Sonogashira reactions and other coupling reactions.The characteristic reactions of alkynes with organocobalt compounds in organic synthesis have been reported in a previous review article. [1] This present review reports mainly on three characteristic reactions of alkynes with the metal compounds in organic synthesis, excluding the organocobalt compounds. * Correspondence to : Iwao Omae, Nihon Pharmaceutical University, 10281 ...

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A heteronuclear .mu.-alkyne complex, [.mu.-(CF3)2C2]CoMo(CO)5(.eta.-C5H5)

Cited by 43 publications

References 0 publications

Reactions of 1,8-Nonadiyne with Co₂(CO)₈ and Mo₂(C₅H₄R)₂(CO)₄ and Crystal Structures of [M₂L₂(CO)₄][μ-HC₂(CH₂)₅C₂H-μ][Mo₂(C₅H₄R)₂(CO)₄] (M = Co, L = CO; M = Mo, L = C₅H₄R, R = H, COCH₃, COOC₂H₅)

Three characteristic reactions of alkynes with metal compounds in organic synthesis

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A heteronuclear .mu.-alkyne complex, [.mu.-(CF3)2C2]CoMo(CO)5(.eta.-C5H5)

Cited by 43 publications

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Reactions of 1,8-Nonadiyne with Co2(CO)8 and Mo2(C5H4R)2(CO)4 and Crystal Structures of [M2L2(CO)4][μ-HC2(CH2)5C2H-μ][Mo2(C5H4R)2(CO)4] (M = Co, L = CO; M = Mo, L = C5H4R, R = H, COCH3, COOC2H5)

Three characteristic reactions of alkynes with metal compounds in organic synthesis

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Reactions of 1,8-Nonadiyne with Co₂(CO)₈ and Mo₂(C₅H₄R)₂(CO)₄ and Crystal Structures of [M₂L₂(CO)₄][μ-HC₂(CH₂)₅C₂H-μ][Mo₂(C₅H₄R)₂(CO)₄] (M = Co, L = CO; M = Mo, L = C₅H₄R, R = H, COCH₃, COOC₂H₅)