Knoevenagel Condensation of Aldehydes with Meldrum's Acid in Ionic Liquids

Tahmassebi, Daryoush; Wilson, Levi J. A.; Kieser, Jerod M.

doi:10.1080/00397910802663345

Cited by 19 publications

(6 citation statements)

References 26 publications

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“…It is pertinent to mention here that Knoevenagel condensation is a facile and versatile method for the formation of acrylonitrile derivatives [42][43][44]. In the quest to achieve higher efficiency several catalysts have been employed viz Brønsted acid catalysts [45], Lewis acids such as MgBr 2 · OEt 2 [46], SnCl 2 [47], Al 2 O 3 [48] ionic liquids [C 6 [51], ethylammonium nitrate (EAN) [52] and silica supported acid catalyst [53,54].…”

Section: Introductionmentioning

confidence: 99%

Silica Bonded N-(Propylcarbamoyl)sulfamic acid (SBPCSA) Mediated Expeditious Approach to C–C Bond Formation: An Innovative Pathway for Acrylonitrile Derivatives

et al. 2016

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A new silica bonded N-(propylcarbamoyl)sulfamic acid (SBPCSA) catalyst has been prepared for the highly efficient synthesis of a series of acrylonitrile derivatives via solvent-free facile Knoevenagel condensation between differently substituted heterocyclic/aromatic aldehydes 1 (a-o) and 2-thiopheneacetonitrile (2). The catalyst was characterized by FT-IR, SEM-EDX and XRD techniques. The thermal stability of the catalyst was evaluated with TGA and DT analysis. The remarkable features of the present protocol are solvent free synthesis, recyclability of the catalyst, mild reaction conditions, shorter reaction profile, excellent yield of products with applicability to broader substrate scope (electron rich and electron deficient) and exclusive formation of E-isomer of the product. DFT calculations also revealed that E-isomer of compound 3f is stabilized by 12.53 kcal mol −1 more than the Z-isomer. Graphical AbstractEfficient and economical synthesis of acrylonitrile derivatives. H O Ar S CN Solvent-free Stirring/ 80 o C Examples:15 Yield: 92-98%

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Section: Introductionmentioning

confidence: 99%

Silica Bonded N-(Propylcarbamoyl)sulfamic acid (SBPCSA) Mediated Expeditious Approach to C–C Bond Formation: An Innovative Pathway for Acrylonitrile Derivatives

et al. 2016

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“…The same reaction was also carried out in water [375]. In addition, the Knoevenagel condensation of aromatic aldehydes with Meldrum's acid proceeded efficiently in the recyclable N. S. El-Gohary ionic liquid [bmim]BF 4 at room temperature and in the presence of a catalytic amount of piperidine [376]. Also, the same condensation was carried out in methanol at room temperature [377].…”

Section: Synthesis Of 5-arylidene Derivatives Of Barbituric and Thiobmentioning

confidence: 99%

Arylidene Derivatives as Synthons in Heterocyclic Synthesis

El‐Gohary¹

2014

OALib

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This review describes the synthetic procedures for the preparation of arylideneacetophenones, arylidenecycloalkanones, 2-arylidene-1-indanones, 2-arylidene-1-tetralones, 2-arylidene-1-benzosuberones, aurones, 1-thioaurones, 3-arylidene-4-chromanones, 3-arylidene-1-thio-4-chromanones, 3-arylideneflavanones, 3-arylidene-1-thioflavanones, arylideneanilines, arylidenemalononitriles, diethyl arylidenemalonates, ethyl arylidenecyanoacetates, arylidenecyanoacetamides, 5arylidene derivatives of barbituric and thiobarbituric acids, arylidene derivatives of Meldrum's acid and arylidene derivatives of dimedone. Also, it demonstrates the reactivity of these arylidene derivatives in heterocyclic synthesis with emphasis on the most recent findings. Some of these are the α,β-enones, víz. aurones and 3-arylidene-4-chromanones belong to the natural products. The others are synthetic substances which are convenient and important intermediates for the synthesis of a variety of useful and novel heterocyclic systems.

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“…Despite various solid catalysts have been employed for the Knoevenagel condensation reaction, such as mesoporous materials [29][30][31], ionic liquids [32,33], organometallic catalysts [34], zeolites [35,36], etc. only few sustainable methods that utilize basic heterogeneous catalyst were reported [37].…”

Section: Introductionmentioning

confidence: 99%