Acetylenic Esters Research Articles

Heteropolyacid-Catalyzed One-Pot Synthesis of 2-Pyridone Derivatives

An efficient Keggin-type heteropolyacid-catalyzed reaction for the synthesis of 2-pyridone derivatives using amines, acetylenic esters, and malonic esters or acid is reported. Optimum conditions were developed in i-PrOH at 60–100 °C. The activity of immobilized H3PW12O40 on the traditional amorphous silica was also examined.

Green approach to stereoselective synthesis of benzo[d]chromeno[3,4- h]oxathiazonine derivatives via MCRs in water: a combined experimental and DFT study.

(7S, 14S, 16R)- dialkyl 6-oxo-6,7,13,14-tetrahydro-7,14-methanobenzo[d]chromeno[3,4- h][1,6,3]oxathiazo-nine-14,16-dicarboxylates 4 and (S)-methyl 2-(2-methoxy-2-oxoethyl)-2,3- dihydrobenzo[d]thiazole-2-carboxylates 5 were readily synthesized in a ratio 3:1 and moderated yield by multicomponent reactions of 4-hydroxycoumarin and acetylenic esters with benzothiazole without using a catalyst. Also, The GIAO/DFT approach at the B3LYP/6-31G** level of theory was used to calculate the (1)H, (15)N, (17)O and (13)C NMR chemical shifts of product 4b. These computations are performed on the basis of X-ray structural data which are collected at 120(2) K temperature. In order to take into account intermolecular hydrogen bonds and the van der Waals effects, two different sizes of clusters (two model of trimeric and pentameric clusters) have been considered. A comparison between the experimental (Exp.) and calculated (Cal.) (1)H and (13)C NMR chemical shifts may reveal that the solution contains monomer, trimer1, trimer2, and pentamer models.

Reaction between thiocarbamidoalkyl naphthols and acetylenic esters: An interesting cyclocondensation reaction for the synthesis of new thiazolidin-4-one derivatives

This investigation was set to provide derivatives of thiazolidin-4-ones incorporated with aminoalkyl naphthols in a molecular frame work. For this purpose, a series of 1-thiocarbamidoalkyl-2-naphthols was prepared by the three component condensation of aromatic aldehydes, phenylthiourea and 2-naphthol. In the next step, these compounds underwent reaction with dialkyl acetylenedicarboxylates at ambient temperature in ethanol to afford the corresponding 4-thiazolidinones in high yields. Following the completion of the reaction, the products were solidified and isolated by filtration. The method is easy, inexpensive, chemoselective and environmentally benign and illustrates an interesting instance of click chemistry.

Regioselective and Stereoselective Addition of Tetrazole Derivatives to Electron‐poor Acetylenic Esters in the Presence of Triphenylphosphine

Protonation of the highly reactive 1:1 intermediates produced in the reaction between triphenylphosphine and acetylenic esters by tetrazole derivatives leads to the formation of vinyltriphenylphosphonium salts. The cation of these salts undergoes an addition reaction with the counter anion in CH2Cl2 at room temperature to yield the corresponding stabilized phosphorus ylides. Elimination of triphenylphosphine from the stabilized phosphorus ylides leads to the corresponding electron‐poor N‐vinyl tetrazoles in fairly high yields. Structures of N‐vinyl tetrazoles were determined by IR, 1H NMR, 13C NMR and single crystal X‐ray structure analyses. The reaction is fairly regioselective and stereoselective.

ChemInform Abstract: Four‐Component Reaction of Alkyl Isocyanide, Acetylenic Esters, Phenols and Pyrrole; Synthesis of Dialkyl 2‐[(Alkylimino)(1H‐pyrrol‐2‐yl)methyl]‐3‐(aryloxy) Succinate.

A new series of dialkyl 2-[(alkylimino)(1H-pyrrol-2-yl)methyl]-3-(aryloxy)succinate derivatives have been synthesised using alkyl isocyanids, acetylenic esters, phenols with electron-withdrawing groups and pyrrole in CH2Cl2 at ambient temperature.

ChemInform Abstract: I2‐Promoted Denitration Strategy: One‐Pot Three Component Synthesis of Pyrrole‐Fused Benzoxazines.

AbstractCoupling of 2‐aminophenols with acetylenic ester (II) affords alkylidene benzoxazine intermediates.

Synthesis of 5,6-dihydroquinolines and succinates via the reaction of α,α-dicyanoolefins and acetylenic esters in a ratio of 2:1

A one-pot, convergent method for the synthesis of 5,6-dihydroquinolines by simple mixing of two equivalents of acyclic α,α-dicyanoolefins and one equivalent of acetylenic ester in the presence of Et3N is described. Three new C–C and one C–N bonds are created in this operation. In the same reaction, cyclic α,α-dicyanoolefins led to the formation of succinates. Further hydrolysis and decarboxylation of 5,6-dihydroquinoline led to quinoline.

Ga(DS)3-catalysed double hydroarylation of acetylenic esters with indoles for the synthesis of bisindolyl propanoates

An efficient synthetic method for bisindolyl propanoates has been developed. Ga(DS)3-catalysed double hydroarylation of acetylenic esters with indoles in water afforded regioselective products with up to 99% yield.

Four-Component Reaction of Alkyl Isocyanide, Acetylenic Esters, Phenols and Pyrrole; Synthesis of Dialkyl 2-[(alkylimino)(1H-pyrrol-2-yl)methyl]-3-(aryloxy) Succinate

A new series of dialkyl 2-[(alkylimino)(1H-pyrrol-2-yl)methyl]-3-(aryloxy)succinate derivatives have been synthesised using alkyl isocyanids, acetylenic esters, phenols with electron-withdrawing groups and pyrrole in CH2Cl2 at ambient temperature.

ChemInform Abstract: Pyridine‐Mediated N‐Vinylation of Heterocyclic Compounds: A Mild, Stereoselective and General Synthesis.

AbstractA variety of N‐vinylated heterocyclic compounds (III) are obtained by simple and effective one‐pot reaction of acetylenic esters and various NH heterocyclic compounds using pyridine as efficient catalyst.

Copper(II)-Catalyzed β-Borylation of Acetylenic Esters in Water

A method for the β-borylation of alkynoates has been developed. In the presence of bis(pinacolato)diboron and catalytic amounts of both copper(II) and 4-picoline, substituted alkynoates undergo borylation in a regio-, stereo-, and chemoselective fashion. The reaction is performed under mild conditions using water as solvent and open to the atmosphere to exclusively afford (<i>Z</i>)-β-boryl-α,β-unsaturated esters.

ChemInform Abstract: A Mild and Efficient Method to Functionalize Azines (Quinoline, Isoquinoline, and Phenanthridine) Using Acetylenic Esters and Heterocyclic NH or 1,3‐Dicarbonyl Compounds.

AbstractA one‐pot three‐component reaction of various N‐heterocycles with acetylenic esters and cyclic secondary amines is developed.

I2-promoted denitration strategy: one-pot three component synthesis of pyrrole-fused benzoxazines

A facile and efficient protocol for the synthesis of pyrrole-fused benzoxazines has been developed via a novel molecular iodine-promoted denitration strategy, involving 2-amino phenols, acetylenic esters and β-nitrostyrene derivatives. This method offers the advantages of being nature friendly by avoiding use of metal catalyst and Brønsted acids, wide substrate scope, good yields, clean and simple methodology.

Facile and Efficient One-Pot Synthesis of Highly Functionalised 1,2,3,5-Tetrahydroimidazo[1,2-A]Pyrimidines

The one-pot, three-component reaction between isocyanides, electron-deficient acetylenic esters and 2-amino-1-methyl-1H-imidazol-4(5H)-one efficiently leads to highly functionalised 1,2,3,5-tetrahydroimidazo[1,2-a]pyrimidines without any activation in excellent yields at room temperature.

ChemInform Abstract: An Approach to the Synthesis of Spiro[indene‐pyridoisoquinoline] Derivatives via 1,4‐Dipolar Cycloaddition of Isoquinoline and Acetylene Esters, and (1,3‐Dihydro‐1,3‐dioxo‐2H‐inden‐2‐ylidene)malononitrile.

A concise and efficient approach to the spiro-tetrahydroisoquinoline derivatives has been developed by 1,4-dipolar cycloaddition of zwitterions resulting from isoquinoline and acetylene esters and (1,3-dihydro-1,3-dioxo-2H-inden-2-ylidene)malononitrile in MeCN at room temperature. The significance of this method lies in good yields and ease of product purification, and no inert atmosphere is required. The structures of the products were confirmed spectroscopically (IR, 1H- and 13C-NMR, and EI-MS) and by elemental analyses. A plausible mechanism for this reaction is proposed (Scheme).

ChemInform Abstract: A Facile Access to Highly Functionalized Triphenylphosphoranylidene Succinimides Through a Three‐Component Reaction and DFT Investigation of the Reaction Mechanism.

AbstractA novel one‐pot reaction of zwitterions generated in situ from triphenylphosphine and acetylenic esters with aroyl isocyanates affords the title compounds (IV) without using any catalyst or activation.

One-Pot Synthesis of Alkyl 4-alkyl-2,8-dioxo-2H,8H-pyrano[2,3- f]chromene-10-carboxylates and Alkyl 2(E)-3-[(4-alkyl-2-oxo-2H-chromen- 7-yl)oxy]acrylates

We report the synthesis of novel alkyl 4-alkyl-2,8-dioxo-2H,8H-pyrano[2,3-f]chromene-10-carboxylates by the reaction of 7-hydroxy coumarins and dialkyl acetylenedicarboxylates in the presence of triphenylphosphine, when alkyl propiolates were employed O-vinylated coumarin derivatives were obtained. Keywords: Acetylenic esters, 7-Hydroxy coumarin derivatives, One-pot synthesis, Triphenylphosphine.

Hydrotelluration of acetylenic esters: structural characterization of stereoisomers of methyl/ethyl β-(aryltelluro)acrylates

Synthesis of tellurated acrylates, ArTeCHCHCOOR and their solid state structures have been explored. The 125Te chemical shift and 2J(1H–125Te) are useful indicators of their geometry in solution.

A green and efficient protocol for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives via a one-pot, four component reaction by grinding method

An efficient grinding protocol for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives from acetylene ester, hydrazine hydrate, aryl aldehydes and malononitrile under solvent free conditions has been achieved with excellent yields. The structures of the synthesized compounds were deduced by spectroscopic techniques and the compounds were further evaluated for their in vitro antioxidant and antimicrobial activities.

Two component reaction for the synthesis of Quinolines in the presence of γ-Al 2 O 3 and Cu/ZnO nanoparticles

Two-component reaction of 2-aminobenzophenones with acetylenic esters in the presence of γ-Al2O3 and Cu/ZnO as suitable heterogeneous catalysts has been studied. Nano γ-Al2O3 and Cu/ZnO showed high activities when used as surface catalysts for the synthesis of quinoline derivatives. After completion of the reaction, the catalyst was recovered and reused several times under the same reaction conditions.