Selektive gekreuzte Tischtschenko‐Reaktion – eine abfallfreie Synthese von Benzylestern

Dzik, Wojciech I.; Gooßen, Lukas J.

doi:10.1002/ange.201105423

Cited by 9 publications

(2 citation statements)

References 26 publications

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“…Boric acid,3h ( i‐ Bu) 2 AlH,3i alkaline earth metal amides,3j,k LiBr/Et 3 N,3l NaH,3b,m,n Grignard reagents in combination with thiolates,3o, selenide ions,3p transition metal complexes based on Fe,4a,b Ru,4c–h Rh,4i–k Os,4l Ir,4m,n Ni,4o,p Zr,4q Hf4q and lanthanide complexes,5a–g particularly lanthanide amides,5b–e and organoactinide complexes5h,i have also been employed for this reaction. Quite recently, this disproportionation reaction between two different selected aldehydes could be accomplished to a certain extent 1f,4p. However, many of these auxiliaries are toxic, not commercially available or expensive, suffer from low reaction rates, require high catalyst loadings, are air‐ and moisture‐sensitive, undergo side reactions, react sluggishly and are inefficient for heteroaromatic aldehydes, which are known to be difficult to disproportionate to esters 3n,7…”

Section: Methodsmentioning

confidence: 99%

Alkali Metal tert‐Butoxides, Hydrides and Bis(trimethylsilyl)amides as Efficient Homogeneous Catalysts for Claisen–Tishchenko Reaction

Rajesh

Berke

2013

Adv Synth Catal

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Shelf-available alkali metal tert-butoxides, hydrides and bis(trimethylsilyl)amides were shown to be highly efficient homogeneous precatalysts for the disproportionation of aldehydes to the corresponding carboxylic esters. Potassium compounds in combination with 18-crown-6 ether could drastically increase the rate of reaction in a few cases. Alternatively, efficient aldol condensations were found for aldehydes possessing an enolizable methylene group at the a-position to the aldehyde functionality. The active species involved in this esterification using any of these alkali metal catalysts is expected to be the metal alkoxide. Potassium compounds were found to be much more efficient when compared to analogous sodium compounds and kinetic studies revealed the rate-determining step to be a second order concerted hydride transfer from a potassium hemiacetal species to another molecule of aldehyde.Simple, efficient and environmentally friendly transformations are challenging goals in chemical synthesis. The greatest achievements in these respects have evoked from the concept of catalysis. Featuring high atom economy, the dimerization or disproportionation of aldehydes to the corresponding carboxylic esters, named Claisen-Tishchenko [1] reaction (Scheme 1), has attracted wide attention for the last century and is applied in the food, polymer, dye and perfume industry as well as for the production of ethyl acetate. [2] A number of compounds of the main group elements, [3] transition metal [4] and rare earth [5] compounds, as well as N-heterocyclic carbenes [6] are found to be active to catalyze this reaction. Traditional catalysts for this process include mainly sodium [3a,b] and in particularly aluminium [3c-g] alkoxides. Boric acid, [3h] (i-Bu) 2 AlH, [3i] alkaline earth metal amides, [3j,k] LiBr/Et 3 N, [3l] NaH, [3b,m,n] Grignard reagents in combination with thiolates, [3o] , selenide ions, [3p] transition metal complexes based on Fe, [4a,b]

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Section: Methodsmentioning

confidence: 99%

Alkali Metal tert‐Butoxides, Hydrides and Bis(trimethylsilyl)amides as Efficient Homogeneous Catalysts for Claisen–Tishchenko Reaction

Rajesh

Berke

2013

Adv Synth Catal

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“…The allyl unit is not delivered by an organometallic reagent to generate a homoallylic alcoholate, but through a cross-disproportionation of a b,g-unsaturated carbonyl compound with another aldehyde to result in a homoallylic ester. Unlike in the crossed-Tishchenko reaction, [6] this disproportionation of two different aldehydes is not the result of a hydride transfer, instead it is brought about by an oxonia-Cope rearrangement to form homoallylic esters and lactones.…”

Section: Dedicated To Professor Georg Frµtermentioning

confidence: 99%

Tandem Cross‐Dimerisation/Oxonia‐Cope Reaction of Carbonyl Compounds to Homoallylic Esters and Lactones

et al. 2012

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Bu₄NI‐Catalyzed and tBuOOH‐Oxidized Esterification of Aldehydes with Alkyl Halides in Water

Wang

et al. 2016

Asian J Org Chem

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The importance of esters has stimulated significant efforts to develop efficient methods for their synthesis. In this study,a no xidative esterification of aldehydes with alkyl halidesb yu sing tert-butyl hydroperoxidea sa n oxidant, Bu 4 NI as catalyst, andw ater as solvent is presented. Notably,t his novel esterification protocol is suitable for both aromatic and aliphatic aldehydes, primary and secondary alkyl halides to give ester products with broad structural diversity. Through an intramolecular version of this novel esterification process, an alternative synthetic approach toward the biologically interesting isobenzofuran-1(3 H)-one was also realized. Compared with literature procedures, the synthetic strategies developed herein showed advantages such as direct use of commercially available and economical starting materials,w ide substrate scope, good tolerance of functional groups, sustainable oxidant, and no need of an inert atmosphere or dry solvents.

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Selektive gekreuzte Tischtschenko‐Reaktion – eine abfallfreie Synthese von Benzylestern

Cited by 9 publications

References 26 publications

Alkali Metal tert‐Butoxides, Hydrides and Bis(trimethylsilyl)amides as Efficient Homogeneous Catalysts for Claisen–Tishchenko Reaction

Alkali Metal tert‐Butoxides, Hydrides and Bis(trimethylsilyl)amides as Efficient Homogeneous Catalysts for Claisen–Tishchenko Reaction

Tandem Cross‐Dimerisation/Oxonia‐Cope Reaction of Carbonyl Compounds to Homoallylic Esters and Lactones

Bu₄NI‐Catalyzed and tBuOOH‐Oxidized Esterification of Aldehydes with Alkyl Halides in Water

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Selektive gekreuzte Tischtschenko‐Reaktion – eine abfallfreie Synthese von Benzylestern

Cited by 9 publications

References 26 publications

Alkali Metal tert‐Butoxides, Hydrides and Bis(trimethylsilyl)amides as Efficient Homogeneous Catalysts for Claisen–Tishchenko Reaction

Alkali Metal tert‐Butoxides, Hydrides and Bis(trimethylsilyl)amides as Efficient Homogeneous Catalysts for Claisen–Tishchenko Reaction

Tandem Cross‐Dimerisation/Oxonia‐Cope Reaction of Carbonyl Compounds to Homoallylic Esters and Lactones

Bu4NI‐Catalyzed and tBuOOH‐Oxidized Esterification of Aldehydes with Alkyl Halides in Water

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Bu₄NI‐Catalyzed and tBuOOH‐Oxidized Esterification of Aldehydes with Alkyl Halides in Water