Stabilisation de l'acetylenedicarbaldehyde. preparation et structure de complexes acetylenedicarbaldehyde-cobaltcarbonyle.

Meyer, Andreas; Gorgues, A.; Floc'h, Y. Le; Pineau, Y.; Guillevic, J.; Marouille, J. Y. Le

doi:10.1016/s0040-4039(01)92453-0

Cited by 30 publications

(23 citation statements)

References 3 publications

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“…Full Xray diffraction data are consistent with partial data previously reported. [2] As in the case of 6, [6] the crystal structure of 4 displays no hint of a possible [Co···C ϩ ϪO Ϫ ] interaction ( Figure 1, Table 1). While no selective electrophilicity is observed in complex 6, regioselectivity is restored at the organic carbonyl centers in complex 4.…”

Section: Resultsmentioning

confidence: 92%

“…[6] In contrast to the typical electronic and steric deactivation of the ketoyl functions in complex 6, the study of the strain-free electrophilicity of the formyl functions in complex 4 deserved separate investigations. According to Gorgues and Meyer's reports, [2,3] diacetal 2 was prepared from acetylene dimagnesium bromide and diethylphenylorthoformate. This diacetal behaves as a normal alkyne ligand of transition metals.…”

Section: Resultsmentioning

confidence: 99%

“…To fit the experimental conditions closer, the model was refined by adding two THF ligands on lithium and one THF ligand on magnesium bromide. With this model, ESFF molecular mechanic calculations showed that in both cases [i.e., M ϭ Li(THF) 2 and M ϭ MgBr(THF)] the minimum-energy structures had quasi-C s conformations, while no quasi-C 2 conformations exist as minima. The minimum C s conformations are of the pseudo-boat type B[M] (Figure 3).…”

Section: Discussionmentioning

confidence: 99%

“…6%) containing 20% of reduced product 7a (δ H ϭ 3.46 ppm). [14] TLC (pentane/Et 2 Trimethylsilyl-3-methoxy-3-phenylhexa-1,4-diyne (MeC 2 )(OMe)-PhC(C 2 SiMe 3 ): This compound was obtained as a byproduct formed during the preparation of 11h by exhaustive methylation of 1-trimethylsilyl-3-hydroxy-3-phenylpenta-1,4-diyne (HC 2 )PhC(OH)-(C 2 SiMe 3 ) with CH 3 I. [21] 1-Trimethylsilyl-3-(2-tetrahydropyranyl)oxypenta-1,4-diyne (11i): A mixture of racemic 1-trimethylsilylpenta-1,4-diyn-3-ol (1.006 g, 6.62 mmol), dihydropyran (1.8 mL, 20 mmol) and p-toluenesulfonic acid (22.9 mg, 0.12 mmol) in toluene (40 mL) was stirred for 6 h at room temp.…”

Section: Acetylenedicarbaldehyde Complexmentioning

confidence: 99%

“…[2,3] Reactions of 4 have been described with amines, [4] phosphorus ylides, [5] and enol ethers. [6] The numerous applications of the Co 2 (CO) 6 -activated substitution of oxypropyne derivatives (Nicholas reactions of propargylic alcohols, ethers, esters, [7] and acetals [8] ) involve formally uncharged nucleophiles [9] (except borohydrides [10] ) in either monopropargylic or bispropargylic versions.…”

Section: Introductionmentioning

confidence: 99%

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Regio‐ and Stereoselective Double Addition of Anionic C‐Nucleophiles to Cobalt‐Stabilized Acetylenedicarbaldehyde

et al. 2003

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Though intrinsically unstable, Gorgues’ acetylenedicarbaldehyde is an appealing, highly functional C4 synthon, which can be stabilized by η2 complexation to a Co2(CO)6 unit. In contrast to the homologous dibenzoylacetylene complex, it can be used as a normal, doubly electrophilic, non‐conjugated γ‐dicarbonyl substrate toward alkyl‐, aryl‐, and alkynyllithium compounds or magnesium bromides; these anionic C‐nucleophiles do not predominantly attack at the metal‐carbonyl center. The 1,4‐dialkyl‐ and 1,4‐diphenylbut‐2‐yne‐1,4‐diol products are obtained with significant meso/dl diastereoselectivity (4−66% de), which can be explained by a simple model based on X‐ray diffraction data and MM calculations. The alkyl‐ and arylmagnesium bromide reactants are more selective than their lithium counterparts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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Section: Resultsmentioning

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Acetylenedicarbaldehyde Complexmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Regio‐ and Stereoselective Double Addition of Anionic C‐Nucleophiles to Cobalt‐Stabilized Acetylenedicarbaldehyde

et al. 2003

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Strategien zum Aufbau molekularer und polymerer Kohlenstoffallotrope

1992

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Das Leben auf der Erde beruht auf Verbindungen mit einem Kohlenstoffgerust. Bis zum heutigen Tage haben Chemiker die Welt der Biomolekule und Biopolymere um etwa lo7 verschiedene synthetische Molekiile und Polymere erweitert, deren Struktur ebenfalls von der Bildung stabiler C-C-Bindungen abhangt. Obwohl die Stabilitat von C-C-Bindungen seit iiber hundert Jahren wohlbekannt ist, waren Graphit und Diamant bis vor kurzem die einzigen auf der Erde in makroskopischen Mengen verfiigbaren und strukturell charakterisierten Kohlenstoffallotrope. Mit der Darstellung makroskopischer Mengen an Buckminsterfulleren C,, und an hoheren Fullerenen wie C,,, C,,, und C,, sowie der Erforschung der faszinierenden Eigenschaften dieser Kohlenstoffkugeln hat sich diese Situation inzwischen drastisch geandert. Im Laufe der kommenden Jahrzehnte wird der Entwurf, die Darstellung und das Studium neuer molekularer und polymerer allotroper Formen des Kohlenstoffs eine zentrale Stellung in der Chemie einnehmen. Dies wird zu einer wesentlichen Vertiefung unserer grundlegenden Kenntnisse iiber die aus Kohlenstoff aufgebaute Materie fiihren und -wie die aktuelle C60-Forschung zeigt -vollig neue Perspektiven fur technologische Entwicklungen bieten. Dieser Artikel gibt eine Ubersicht iiber organisch-chemische Synthesestrategien fur ausschlieljlich aus Kohlenstoff aufgebaute Molekiile und Polymere, welche strukturell von den bekannten Graphit-und Diamant-Netzwerken und auch von den Fullerenen abweichen. Wir diskutieren auch die aktuelle Fullerenforschung, wobei wir besonderes Gewicht auf die Synthesestrategien legen wollen, welche zu den Fullerenen sowie deren Ubergangsmetallkomplexen fuhren.

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Synthetic Approaches toward Molecular and Polymeric Carbon Allotropes

Diederich

Rubin

1992

Angew. Chem. Int. Ed. Engl.

642

249

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Life on earth is based on compounds that have carbon frames and backbones. Today, chemists have added to the world of biomolecules and biopolymers approximately lo7 different synthetic molecules and polymers, the structures of which also depend on the formation of strong, stable carbon-carbon bonds. Although the stability of carbon-carbon bonds has been recognized for more than a century, the two natural modifications graphite and diamond were, until recently. the only allotropic forms of carbon on earth that were available in macroscopic quantities and were structurally well characterized. With the synthesis of macroscopic quantities of buckminsterfullerene (C6,) and the higher fullerenes (C,,, C 7 6 , C,,, etc.) and the exploration of the fascinating properties of these all-carbon spheres, this situation has completely changed. In the coming decades, the design, preparation, and study of novel molecular and polymeric allotropic forms of carbon will be a central topic in chemistry. Research in this area will dramatically advance the fundamental knowledge on carbon-based matter and, as already illustrated by the ongoing work on C,, , generate unprecedented technological perspectives. This review surveys synthetic organic-chemical approaches toward the preparation and study of all-carbon molecules and polymers that differ from the familiar networks of graphite and diamond as well as from the fullerenes. We will also discuss the ongoing research on fullerenes with a particular focus on the synthetic approaches to these all-carbon spheres and their transition metal complexes.

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Stabilisation de l'acetylenedicarbaldehyde. preparation et structure de complexes acetylenedicarbaldehyde-cobaltcarbonyle.

Cited by 30 publications

References 3 publications

Regio‐ and Stereoselective Double Addition of Anionic C‐Nucleophiles to Cobalt‐Stabilized Acetylenedicarbaldehyde

Regio‐ and Stereoselective Double Addition of Anionic C‐Nucleophiles to Cobalt‐Stabilized Acetylenedicarbaldehyde

Strategien zum Aufbau molekularer und polymerer Kohlenstoffallotrope

Synthetic Approaches toward Molecular and Polymeric Carbon Allotropes

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