Carboxylates as pronucleophiles in the phosphine-catalyzed γ-addition reaction

Alvarez‐Ibarra, Carlos; Csákÿ, Aurelio G.; Oliva, Cristina Gómez de la

doi:10.1016/s0040-4039(99)01775-x

Cited by 36 publications

(18 citation statements)

References 8 publications

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“…Eine interessante Möglichkeit ist der nucleophile Angriff durch ein externes Reagens an der gPosition von XXVIII, da dies der a 4 -Reaktivitätsumpolung des ursprünglichen Alkinoats entspricht. [123] Alkohole, [124] Amine, [125] Carbonsäuren, [126] Malonate, [127] Glycinimine und Nitroalkane [128] reagieren unter g-Addition an XXXV oder XXXVI zu den Produkten 84 bzw. 85 (Schema 29).…”

Section: 3unclassified

Lewis‐Base‐Katalyse in der organischen Synthese

2008

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Das Erbe von Gilbert Newton Lewis (1875–1946) ist im Wörterbuch der chemischen Bindung und Reaktivität allgegenwärtig. Die Bedeutung seines Konzepts der Donor‐Akzeptor‐Bindung kommt in den eponymen Grundbegriffen für Elektronenpaarakzeptoren (Lewis‐Säuren) und ‐donoren (Lewis‐Basen) zum Ausdruck. Lewis erkannte, dass Säuren nicht automatisch Wasserstoff enthalten müssen (Brønsted‐Säuren) und trug so zum Sturz des “modernen Protonenkults” bei. Seine Entdeckung läutete zunächst die Entwicklung von Lewis‐Säuren als Reagentien und Katalysatoren für organische Reaktionen ein, in den letzten Jahren wurde aber offensichtlich, dass für diese Zwecke auch Lewis‐Basen eingesetzt werden können. Bezüglich der Beschleunigung chemischer Reaktionen ergänzen Lewis‐Basen die entsprechenden Lewis‐Säuren nicht nur elektronisch: Tatsächlich können Lewis‐Basen die Elektrophilie wie auch die Nucleophilie der Verbindungen verstärken, an die sie gebunden werden. Diese unterschiedliche Reaktivität resultiert in einer bemerkenswerten Vielfalt Lewis‐Base‐katalysierter Reaktionen.

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Section: 3unclassified

Lewis‐Base‐Katalyse in der organischen Synthese

2008

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“…Alvarez-Ibarra reported carboxylates as pronucleophiles in a similar phosphine-catalyzed g-addition to both alkynyl esters and ketones, with both aliphatic and aromatic carboxylic acids (Scheme 5.5). [54] Potential exists for asymmetric synthesis using chiral phosphines in the g-addition reaction. Recently Zhang and coworkers reported the application of their phosphabicyclo[2.2.1]heptane catalysts to this problem (Scheme 5.6).…”

Section: Nucleophilic Addition To the A-and Gpositions Of Activated Amentioning

confidence: 99%

Nucleophilic Phosphine Organocatalysis

2004

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Phosphines have recently become popular choices as nucleophilic catalysts in organic synthesis. The unique reactivity of phosphines compared to amines has allowed the discovery of new nucleophilic addition reactions at the a-and g-positions of unsaturated carbonyl compounds, as well as novel [3 þ 2] and [4 þ 2] cycloaddition reactions of activated alkynes and alkenes. The accessibility of chiral phosphines has rendered several of these transformations enantioselective and has made possible the kinetic resolution of racemic secondary alcohols by phosphine-catalyzed acylation. This mini-review presents recent advances in nucleophilic phosphine organocatalysis for carbon-carbon bond formation.

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“…Overall, after 8 h of reaction, moderate yields were obtained for ketone-, aldehyde-and tosylamine-containing substrates (compounds [27][28][29]. Of note the cross-metathesis involving eugenol (essential oil of clove) did not require the protection of its phenolic function to obtain 28.…”

Section: Resultsmentioning

confidence: 99%

Ruthenium‐Indenylidene Complexes: Scope in Cross‐Metathesis Transformations

et al. 2008

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A comparative study examining the catalytic activity of a series of five indenylidene-containing ruthenium complexes in olefin cross-metathesis reactions is presented. Results reveal the greater efficiency of precatalyst 5, highlighting the key role of the N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) ligand for this transformation. The scope of this precatalyst was investigated and several microwave experiments were carried out allowing for catalyst loadings as low as 0.1 mol%. Overall, crossmetathesis products were isolated in moderate to excellent yields with high stereoselectivity.

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Carboxylates as pronucleophiles in the phosphine-catalyzed γ-addition reaction

Cited by 36 publications

References 8 publications

Lewis‐Base‐Katalyse in der organischen Synthese

Lewis‐Base‐Katalyse in der organischen Synthese

Nucleophilic Phosphine Organocatalysis

Ruthenium‐Indenylidene Complexes: Scope in Cross‐Metathesis Transformations

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