Disulfonimid‐katalysierte asymmetrische vinyloge und bisvinyloge Mukaiyama‐Aldolreaktionen

Ratjen, Lars; García‐García, Pilar; Lay, Frank; Beck, Michael Edmund; List, Benjamin

doi:10.1002/ange.201005954

Cited by 66 publications

(22 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The catalyst was shown to be quite broad in scope, providing aldol products from isobutyrate- and acetate-derived ketene acetals in high yields and enantioselectivity (Scheme 24a). [98] …”

Section: Chiral Anion-directed Catalysismentioning

confidence: 99%

Asymmetric Ion‐Pairing Catalysis

2012

View full text Add to dashboard Cite

Charged intermediates and reagents are ubiquitous in organic transformations. The interaction of these ionic species with chiral neutral, anionic, or cationic small molecules has emerged as a powerful strategy for catalytic, enantioselective synthesis. This review describes developments in the burgeoning field of asymmetric ion-pairing catalysis with an emphasis on the insights that have been gleaned into the structural and mechanistic features that contribute to high asymmetric induction.

show abstract

“…The catalyst was shown to be quite broad in scope, providing aldol products from isobutyrate- and acetate-derived ketene acetals in high yields and enantioselectivity (Scheme 24a). [98] …”

Section: Chiral Anion-directed Catalysismentioning

confidence: 99%

Asymmetric Ion‐Pairing Catalysis

2012

View full text Add to dashboard Cite

show abstract

“…[71] Im ersteren Fall lieferte die Reaktion von 2-Naphthaldehyd 82 mit dem Nucleophil 93 das Aldol 94 in einer ausgezeichneten Ausbeute und Enantioselektivität sowie mit vollständiger Regioselektivität. [71] Im ersteren Fall lieferte die Reaktion von 2-Naphthaldehyd 82 mit dem Nucleophil 93 das Aldol 94 in einer ausgezeichneten Ausbeute und Enantioselektivität sowie mit vollständiger Regioselektivität.…”

Section: Anwendungen In Der Lewis-säurekatalyseunclassified

Asymmetrische Gegenanionen‐vermittelte Katalyse: Konzept, Definition und Anwendungen

2012

Self Cite

View full text Add to dashboard Cite

Seit einiger Zeit hat sich die Verwendung enantiomerenreiner Gegenanionen zur Induktion von Enantioselektivität in Reaktionen über kationische Intermediate als interessantes neues Konzept hervorgetan, das als “asymmetrische Gegenanionen‐vermittelte Katalyse” (ACDC) bezeichnet wird. Trotz seines Erfolgs ist das Konzept bisher noch nicht vollständig definiert und systematisch diskutiert worden. Dieser Aufsatz schließt diese Lücke, indem eine klare Definition von ACDC gegeben wird und auf sowohl eindeutige als auch mehrdeutige Beispiele angewendet wird, um die Unterschiede und Gemeinsamkeiten zu anderen Katalysekonzepten hervorzuheben.

show abstract

“…[8,9] We hypothesized that such a catalyst could also promote the mechanistically related HDA reactions of 1,3-bis(silyloxy)-1,3-dienes, which surprisingly have previously been utilized only in non-asymmetric catalysis. [10][11][12] Our interest in this particular transformation was further stimulated by speculating that the lack of established catalytic asymmetric HDA reactions might stem from a competing silylium-catalyzed background reaction.…”

mentioning

confidence: 99%

Highly Enantioselective Hetero‐Diels–Alder Reaction of 1,3‐Bis(silyloxy)‐1,3‐dienes with Aldehydes Catalyzed by Chiral Disulfonimide

2012

Self Cite

View full text Add to dashboard Cite

Originating from observation by Danishefsky et al. that hetero-Diels-Alder (HDA) reactions of 1-methoxy-3-(trimethylsilyloxy)butadiene (Danishefskys diene) with aldehydes are accelerated by Lewis acids [Eq. (1); TMS = trimethylsilyl], [1] asymmetric variants became extensively studied and utilized in the synthesis of enantioenriched six-membered oxygen-containing heterocycles.[2] Indeed, several efficient metal-based chiral Lewis acids have been developed for this reaction.[3] Recently, Rawal and co-workers introduced a metal-free, hydrogen-bonding catalyst for asymmetric HDA reactions of 1-dimethylamino-3-tert-butyldimethylsilyloxy-1,3-butadiene (Rawals diene) with aldehydes [Eq. (1), TBS = tert-butyldimethylsilyl].[4] Despite all this progress however, the present catalytic systems for asymmetric HDA reactions are largely limited to the originally introduced dienes, and substituted and functionalized dienes have proven to be highly challenging substrates.[3c,e,g, 5] As a consequence, only few catalytic asymmetric syntheses of 2,6-disubstituted dihydropyrones have been reported and the catalytic enantioselective synthesis of 2,5,6-trisubstituted dihydropyrones is entirely unknown. [6,7] Herein, we report a highly enantioselective HDA reaction of aldehydes with substituted 1,3-bis(silyloxy)-1,3-dienes catalyzed by a novel, highly fluorinated, chiral disulfonimide [Eq. (2)].Recently our group has introduced chiral disulfonimides (DSI) as effective catalysts of asymmetric Mukaiyama and vinylogous Mukaiyama aldol reactions with aldehydes. [8,9] We hypothesized that such a catalyst could also promote the mechanistically related HDA reactions of 1,3-bis(silyloxy)-1,3-dienes, which surprisingly have previously been utilized only in non-asymmetric catalysis. [10][11][12] Our interest in this particular transformation was further stimulated by speculating that the lack of established catalytic asymmetric HDA reactions might stem from a competing silylium-catalyzed background reaction.[13] We had previously shown that disulfonimide-based catalysis offers an efficient solution to this problem in Mukaiyama aldolizations.To explore the principal utility of our DSI catalysts in HDA reactions, we initially studied our previously used chiral disulfonimide catalyst 1 in the reaction of 2-naphthaldehyde with the commercially available diene 3. These experiments showed that the product 4 could indeed be obtained in the presence of 5 mol % of catalyst 1 at À78 8C in Et 2 O in good yield and reasonable enantioselectivity (Table 1, entry 1). We reasoned that improving the steric and electronic properties of the catalyst by incorporating large perfluorinated substitu- e.r.

show abstract

Disulfonimid‐katalysierte asymmetrische vinyloge und bisvinyloge Mukaiyama‐Aldolreaktionen

Cited by 66 publications

References 62 publications

Asymmetric Ion‐Pairing Catalysis

Asymmetric Ion‐Pairing Catalysis

Asymmetrische Gegenanionen‐vermittelte Katalyse: Konzept, Definition und Anwendungen

Highly Enantioselective Hetero‐Diels–Alder Reaction of 1,3‐Bis(silyloxy)‐1,3‐dienes with Aldehydes Catalyzed by Chiral Disulfonimide

Contact Info

Product

Resources

About