Die Beckmannsche Umlagerung des Cyclohexanonoxims. Kinetik der Reaktions-Endphase. I.

Wichterle, O.; Rocek, Jan

doi:10.1135/cccc19510591

Cited by 20 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As a first example of the powerful hetero‐Diels–Alder reaction we highlight a case where two heteroatoms are present in the dienophilic unit. Despite a report in the 1950s that describes the ability of N ‐sulfinylaniline to undergo reaction with 1,3‐dienes in Diels–Alder fashion,49 this particular variant of the Diels–Alder cycloaddition remained, for the most part, an obscure entry in the literature until extensive studies much later honed this mode of reaction into a sharp synthetic tool. The overall power of this hetero‐Diels–Alder‐based methodology is beautifully illustrated in the total synthesis of agelastatin A ( 99 , Scheme 14) by Weinreb and co‐workers,50 the climax of extensive mechanistic studies and several creative syntheses achieved in this arena by this research group 51.…”

Section: Hetero‐diels–alder Reactionsmentioning

confidence: 99%

The Diels-Alder Reaction in Total Synthesis

Nicolaou

Snyder

Montagnon

et al. 2002

Angew. Chem. Int. Ed.

1,655

778

View full text Add to dashboard Cite

The Diels–Alder reaction has both enabled and shaped the art and science of total synthesis over the last few decades to an extent which, arguably, has yet to be eclipsed by any other transformation in the current synthetic repertoire. With myriad applications of this magnificent pericyclic reaction, often as a crucial element in elegant and programmed cascade sequences facilitating complex molecule construction, the Diels–Alder cycloaddition has afforded numerous and unparalleled solutions to a diverse range of synthetic puzzles provided by nature in the form of natural products. In celebration of the 100th anniversary of Alder's birth, selected examples of the awesome power of the reaction he helped to discover are discussed in this review in the context of total synthesis to illustrate its overall versatility and underscore its vast potential which has yet to be fully realized.

show abstract

Section: Hetero‐diels–alder Reactionsmentioning

confidence: 99%

The Diels-Alder Reaction in Total Synthesis

Nicolaou

Snyder

Montagnon

et al. 2002

Angew. Chem. Int. Ed.

1,655

778

View full text Add to dashboard Cite

show abstract

“…Most fast chemical processes require premixing of all reactants for process initiation and intensive mixing for high conversion and selectivity [6][7][8]. For the reaction discussed here, the activation energy is reported [1] as 104 ± 2 kJ mol -1 . These reaction rates are on their own dependent on their local concentrations.…”

Section: Introductionmentioning

confidence: 93%

“…The selectivity of a chemical reaction is dependent on the reaction rate to the desired product and the reaction rate to by-products. At this temperature, the reaction rate with fuming sulfuric acid is very high [1][2][3]. The selectivity of the Beckmann rearrangement is very much dependent on the mixing conditions of the reactants [1,2,9].…”

Section: Introductionmentioning

confidence: 96%

Beckmann Rearrangement of Cyclohexanone Oxime to ϵ‐Caprolactam in a Microreactor

et al. 2012

View full text Add to dashboard Cite

The selectivity and conversion of the sulfuric acid-catalyzed Beckmann rearrangement of cyclohexanone oxime, dissolved in cyclooctane, to e-caprolactam are determined in a microreactor for conditions with a high concentration of e-caprolactam. The microreactor consists of a low-temperature mixing zone followed by a high-temperature reaction zone. The mixing is conducted in a splitand-recombine micromixer and a microchannel at 65°C, followed immediately by a second microchannel at 100-127°C to obtain complete conversion. Under these conditions a selectivity of 99 % is achieved. The residence time of the reactants in the microreactor setup is about 10 s. In literature, a selectivity of about 95 % for the same reaction in a similar setup is reported, but at a uniform temperature of 120-130°C for mixing and reaction. So, suppressing the reaction during mixing is a major tool to enhance the selectivity to e-caprolactam.

show abstract

“…Als erstes Beispiel für die äußerst leistungsfähige Hetero‐Diels‐Alder‐Reaktion möchten wir einen Fall vorstellen, in dem die Dienophil‐Einheit zwei Heteroatome enthält. Obwohl bereits in den 50er Jahren von der Möglichkeit berichtet wurde, N ‐Sulfinylanilin als 1,3‐Dien in der Diels‐Alder‐Reaktion einzusetzen,49 blieb diese Variante der Diels‐Alder‐Cycloaddition ein obskurer Einzelfall in der Literatur, bis ausgiebige Studien diesen Prozess etliche Jahre später in ein brauchbares Hilfsmittel für die Synthese umwandelten. Die Stärke dieses Hetero‐Diels‐Alder‐Prozesses zeigt sich eindrucksvoll in der Totalsynthese von Agelastatin A 99 (Schema ) von Weinreb et al,50 die einen Höhenpunkt der ausgiebigen Studien von Reaktionsmechanismen und kreativen Totalsynthesen dieser Gruppe darstellt 51.…”

Section: Die Hetero‐diels‐alder‐reaktionunclassified

Die Diels-Alder-Reaktion in der Totalsynthese

et al. 2002

View full text Add to dashboard Cite

In den letzten Jahrzehnten hat wohl keine andere Reaktion das Forschungsgebiet der Totalsynthese mehr geprägt als die Diels‐Alder‐Reaktion. Mit einer Vielzahl von Anwendungen dieser großartigen pericyclischen Reaktion, oftmals als entscheidendes Element einer eleganten Kaskadenreaktion zur Herstellung komplexer Molekülstrukturen, ermöglichte die Diels‐Alder‐Cycloaddition die Lösung einer Reihe unterschiedlicher, von der Natur in Form von Naturstoffen gestellter Syntheseprobleme. Zur Feier des hundertjährigen Jubiläums von Alders Geburtstag soll dieser Aufsatz die ungemeine Leistungsfähigkeit der von ihm entdeckten Reaktion anhand ausgewählter Beispiele im Kontext der Totalsynthese verdeutlichen und ihre Vielseitigkeit sowie ihr gewaltiges, noch immer nicht vollständig erfasstes Potential unterstreichen.

show abstract

Die Beckmannsche Umlagerung des Cyclohexanonoxims. Kinetik der Reaktions-Endphase. I.

Cited by 20 publications

References 0 publications

The Diels-Alder Reaction in Total Synthesis

The Diels-Alder Reaction in Total Synthesis

Beckmann Rearrangement of Cyclohexanone Oxime to ϵ‐Caprolactam in a Microreactor

Die Diels-Alder-Reaktion in der Totalsynthese

Contact Info

Product

Resources

About