Selective synthesis of α-substituted β-keto esters from aldehydes and diazoesters on mesoporous silica catalysts

Murata, Hiroaki; Ishitani, Haruro; Iwamoto, Masakazu

doi:10.1016/j.tetlet.2008.05.077

Cited by 39 publications

(14 citation statements)

References 20 publications

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“…Therefore, Al-MCM-41 has been shown to catalyze several organic transformations. [13][14][15][16][17][18][19] However, most of these reactions are vapor phase or high-temperature reactions, [13][14][15][16][17] and there has been relatively few reports on the synthetic application of Al-MCM-41 as a solid acid catalyst for liquid-phase reactions under mild reaction conditions. 18,19 Herein, we report the facile catalytic system for the reaction of aldehydes with allylsilanes by using Al-MCM-41.…”

Section: Introductionmentioning

confidence: 99%

“…[13][14][15][16][17][18][19] However, most of these reactions are vapor phase or high-temperature reactions, 13-17 and there has been relatively few reports on the synthetic application of Al-MCM-41 as a solid acid catalyst for liquid-phase reactions under mild reaction conditions. 18,19 Herein, we report the facile catalytic system for the reaction of aldehydes with allylsilanes by using Al-MCM-41.Al-MCM-41 (Si/Al = 26) was synthesized by a known procedure with slight modification, 20,21 and was used after drying at 120°C for 1 h under vacuum. First, the effect of solvent was examined for the reaction of benzaldehyde (1.0 mmol) and allyltrimethylsilane (1.5 mmol) in the presence of Al-MCM-41 (30 mg).…”

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confidence: 99%

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Mesoporous aluminosilicate-catalyzed allylation of aldehydes with allylsilanes

Ito

Yamaguchi

Kubota

et al. 2009

Tetrahedron Letters

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Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Mesoporous aluminosilicate-catalyzed allylation of aldehydes with allylsilanes

Ito

Yamaguchi

Kubota

et al. 2009

Tetrahedron Letters

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“…These reaction pathways were further supported by the following experiments. Mesoporous silica materials containing very small amounts of aluminum ions, MCM-41, were reported to exhibit weak and uniform acid sites [29][30][31][32][33][34][35][36][37][38][39][40][41]. The uniformity of MCM-41 resulted in excellent selectivity of products in various organic synthesis reactions [29][30][31][32][33][34][35].…”

Section: Reaction Pathways and Reactivity Of Various Compoundsmentioning

confidence: 99%

“…Mesoporous silica materials containing very small amounts of aluminum ions, MCM-41, were reported to exhibit weak and uniform acid sites [29][30][31][32][33][34][35][36][37][38][39][40][41]. The uniformity of MCM-41 resulted in excellent selectivity of products in various organic synthesis reactions [29][30][31][32][33][34][35]. In the current reaction on MCM-41, C5 and C3 compounds were obtained stoichiometrically with 100% conversions of 2-octanol at 623-773 K, and no further reaction, such as the scission reaction of C-C bonds of the C5 compounds, was observed due to the weak acidity of the MCM-41 catalyst [36][37][38][39][40][41].…”

Section: Reaction Pathways and Reactivity Of Various Compoundsmentioning

confidence: 99%

Selective Production of Aromatics from 2-Octanol on Zinc Ion-Exchanged MFI Zeolite Catalysts

2015

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Abstract:The aromatization of 2-octanol derived from castor oil as a byproduct in the formation of sebacic acid was investigated on various zeolite catalysts. Zn ion-exchanged MFI (ZSM-5) zeolites with small silica/alumina ratios and zinc contents of 0.5 to 2.0 wt. % were determined to exhibit good and stable activity for the reaction at 623 to 823 K. The yield of aromatics was 62% at 773 K and the space velocity 350 to 1400 h −1. The temperature and contact time dependences of the product distributions indicated the reaction pathways of 2-octanol→dehydration to 2-octene→decomposition to C5 and C3 compounds→further decomposition to small alkanes and alkenes→aromatization with dehydrogenation. Alcohols with carbon numbers of 5 to 8 exhibited similar distributions of products compared to 2-octanol, while corresponding carbonyl compounds demonstrated different reactivity.

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“…These factors revealed that using β-keto esters as an intermediate is the broadest and most efficient way to synthesize pyrazolones. There are methods to synthesize β-keto esters from esters [34-37] (Claisen condensation) and aldehydes [38,39], but these methods have main limitation in varying the substituents. Often, a number of methods such as acylation of enolates of malonates [40,41], acylation of Meldrum's acid [42-45], mixed malonate esters [46,47] and bistrimethylsilylmalonate [48,49] have a chelating effect employed to lock the enolate anion of malonate using lithium and magnesium salts [50,51]; however, these methods suffer from inconsistent yields in the case of aliphatic acylation.…”

Section: Introductionmentioning

confidence: 99%

β-Keto esters from ketones and ethyl chloroformate: a rapid, general, efficient synthesis of pyrazolones and their antimicrobial, in silico and in vitro cytotoxicity studies

et al. 2013

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BackgroundPyrazolones are traditionally synthesized by the reaction of β-keto esters with hydrazine and its derivatives. There are methods to synthesize β-keto esters from esters and aldehydes, but these methods have main limitation in varying the substituents. Often, there are a number of methods such as acylation of enolates in which a chelating effect has been employed to lock the enolate anion using lithium and magnesium salts; however, these methods suffer from inconsistent yields in the case of aliphatic acylation. There are methods to synthesize β-keto esters from ketones like caboxylation of ketone enolates using carbon dioxide and carbon monoxide sources in the presence of palladium or transition metal catalysts. Currently, the most general and simple method to synthesize β-keto ester is the reaction of dimethyl or ethyl carbonate with ketone in the presence of strong bases which also requires long reaction time, use of excessive amount of reagent and inconsistent yield. These factors lead us to develop a simple method to synthesize β-keto esters by changing the base and reagent.ResultsA series of β-keto esters were synthesized from ketones and ethyl chloroformate in the presence of base which in turn are converted to pyrazolones and then subjected to cytotoxicity studies towards various cancer cell lines and antimicrobial activity studies towards various bacterial and fungal strains.ConclusionThe β-keto esters from ethyl chloroformate was successfully attempted, and the developed method is simple, fast and applicable to the ketones having the alkyl halogens, protecting groups like Boc and Cbz that were tolerated and proved to be useful in the synthesis of fused bicyclic and tricyclic pyrazolones efficiently using cyclic ketones. Since this method is successful for different ketones, it can be useful for the synthesis of pharmaceutically important pyrazolones also. The synthesized pyrazolones were subjected to antimicrobial, docking and cytotoxicity assay against ACHN (human renal cell carcinoma), Panc-1 (human pancreatic adenocarcinoma) and HCT-116 (human colon cancer) cell line, and lead molecules have been identified. Some of the compounds are found to have promising activity against different bacterial and fungal strains tested.

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Selective synthesis of α-substituted β-keto esters from aldehydes and diazoesters on mesoporous silica catalysts

Cited by 39 publications

References 20 publications

Mesoporous aluminosilicate-catalyzed allylation of aldehydes with allylsilanes

Mesoporous aluminosilicate-catalyzed allylation of aldehydes with allylsilanes

Selective Production of Aromatics from 2-Octanol on Zinc Ion-Exchanged MFI Zeolite Catalysts

β-Keto esters from ketones and ethyl chloroformate: a rapid, general, efficient synthesis of pyrazolones and their antimicrobial, in silico and in vitro cytotoxicity studies

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