A new and efficient route to 4-carboxymethylcoumarins mediated by vinyltriphenylphosphonium salt

Yavari, Issa; Hekmatshoar, Rahim; Zonouzi, Afsaneh

doi:10.1016/s0040-4039(98)00206-8

Cited by 265 publications

(134 citation statements)

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“…The synthesis of coumarin molecules has been established using different approaches such as Pechmann condensation [22][23][24][25], Perkin reaction [26][27][28], Witting reaction [29][30][31], Claisen rearrangement [32], Reformatsky reaction [33], Knoevenagel condensation [34][35][36][37], and flash vacuum pyrolysis [38]. Among the mentioned methods, the Pechmann reaction remains one of the most successful techniques to synthesize coumarin compounds.…”

Section: Introductionmentioning

confidence: 99%

Catalytic Activity of Sulfated and Phosphated Catalysts towards the Synthesis of Substituted Coumarin

et al. 2018

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New modified acidic catalysts were prepared from the treatment of silica, titania and silica prepared from hydrolyzed tetraethyl orthosilicate (TEOS) with sulfuric and phosphoric acid. The sulfated and phosphated silica synthesized from TEOS were calcined at 450 and 650 • C. These catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), and scanning electron microscope (SEM). The surface areas, total pore volume, and mean pore radius of the acidic catalysts were investigated, while the pore size distribution was determined by the Barrett, Joyner and Halenda (BJH) method. The catalytic activity of the sulfated and phosphated silica and/or titania were examined with the Pechmann condensation reaction, in which different phenols reacted with ethyl acetoacetate as a neat reaction to obtain the corresponding coumarin derivatives. The results indicated that the treatment of the catalysts with sulfuric or phosphoric acid led to a decrease in the phases' crystallinity to a certain degree. The morphology and the structure of the acidified catalysts were examined and their particle size was calculated. Furthermore, the amount of the used catalysts played a vital role in controlling the formation of the products as well as their performance was manipulated by the number and nature of the active acidic sites on their surfaces. The obtained results suggested that the highest catalytic conversion of the reaction was attained at 20 wt % of the catalyst and no further increase in the product yield was detected when the amount of catalyst exceeded this value. Meanwhile the phenol molecules were a key feature in obtaining the final product.

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Section: Introductionmentioning

confidence: 99%

Catalytic Activity of Sulfated and Phosphated Catalysts towards the Synthesis of Substituted Coumarin

et al. 2018

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“…Furthermore, although P(RNCH 2 CH 2 ) 3 N as an efficient promoter (Kisanga et al, 2002) has been introduced recently, the reaction has to be conducted in benzene or isobutyronitrile, which are not environmentally friendly solvents. Alternatively, coumarins could also be synthesized by other methods including Pechmann (Gu et al, 2005;Fang et al, 2008), Perkin (Camur and Bulut, 2008), Reformatsky (Chen et al, 2005), Wittig (Yavari et al, 1998) reactions, and by flash vacuum pyrolysis (Cartwright and McNab, 1997).…”

Section: Introductionmentioning

confidence: 99%

L-Proline as an efficient and reusable promoter for the synthesis of coumarins in ionic liquid

Liu

Fan

Liu

et al. 2008

J. Zhejiang Univ. Sci. B

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Abstract:The effect of L-proline as a promoter on the condensation reaction of salicylaldehyde or its derivatives with ethyl acetoacetate in neutral ionic liquid [emim]BF 4 was studied. All reactions were carried out under mild reaction conditions and achieved high yields. Moreover, the ionic liquid containing L-proline could be recycled and reused for several times without noticeably decreasing in productivity. The results show that the L-proline-[emim]BF 4 system has a potential in contribution to the development of environmentally friendly and inexpensive processes in organic syntheses.

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“…Mechanistically, 15,16 it is conceivable that the reaction involves the initial formation of a zwitterionic intermediate between Ph 3 P and the acetylenic compound and subsequent protonation of reactive 1:1 adduct followed by electrophilic attack of vinyltriphenylphosphonium cation on the aromatic ring at the ortho position relative to the strong activation group. The product is presumably produced by intramolecular lactonization of the unsaturated diester 5 (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

“…[10][11][12][13][14] We have recently described a new and operationally convenient approach to the synthesis of carboxymethyl coumarines based on aromatic electrophilic substitution reaction between the conjugate base of substituted phenols, catechol, resorcinol, hydroquinone, and pyrogallol. 15,16 In continuation of our current interest in the development of new routes to heterocyclic and carbocyclic systems, [17][18][19] we report here a simple one-pot synthesis of functionalized 5-Aza coumarines 3, 4. Thus, reaction of 3-hydroxypyridine 1 with dialkyl acetylenedicarboxylate 2 in the presence of triphenylphosphine leads to the corresponding coumarins 3, 4 (Scheme 1).…”

Section: Introductionmentioning

confidence: 98%

Synthesis of Aza Coumarines by Nucleophilic Addition of Acetylenic Esters Catalysed by Ph3P

Mohtat¹,

Yavari²,

Ameri³

et al. 2011

Croat. Chem. Acta

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A new and efficient route to 4-carboxymethylcoumarins mediated by vinyltriphenylphosphonium salt

Cited by 265 publications

References 5 publications

Catalytic Activity of Sulfated and Phosphated Catalysts towards the Synthesis of Substituted Coumarin

Catalytic Activity of Sulfated and Phosphated Catalysts towards the Synthesis of Substituted Coumarin

L-Proline as an efficient and reusable promoter for the synthesis of coumarins in ionic liquid

Synthesis of Aza Coumarines by Nucleophilic Addition of Acetylenic Esters Catalysed by Ph3P

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