scholarly journals Camphor-10-sulfonic acid catalyzed condensation of 2-naphthol with aromatic/aliphatic aldehydes to 14-aryl/alkyl-14H-dibenzo[a,j]xanthenes

2014 ◽  
Vol 79 (9) ◽  
pp. 1051-1058 ◽  
Author(s):  
Kshama Kundu ◽  
Sandip Nayak
Keyword(s):  
Microwave Irradiation ◽  
Sulfonic Acid ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
Alkyl Aryl ◽  
Aliphatic Aldehydes ◽  
Acid Catalyzed ◽  
High Yields ◽  
Low Catalyst Loading ◽  
Sole Product

(?)-Camphor-10-sulfonic acid (CSA) catalyzed condensation of 2-naphthol with both aliphatic/aromatic aldehydes at 80?C yielded 14-alkyl/aryl-dibenzoxanthenes as the sole product in high yields. However, the same condensation with benzaldehyde at 25?C afforded a mixture of intermediate 1,1-bis-(2-hydroxynaphthyl)phenylmethane and 14-phenyl-dibenzoxanthene while the condensation with aliphatic aldehydes at 25?C furnished the corresponding 14-alkyl-dibenzoxanthenes as the sole product. Moreover, condensation of 2-naphthol with aromatic/aliphatic aldehydes with low catalyst loading (2 mol%) was greatly accelerated under microwave irradiation to afford the corresponding 14-aryl/alkyl-dibenzoxanthenes as the sole product in high yields.

Three-Component Synthesis of 4-Arylidene-3-alkylisoxazol-5(4H)-ones in the presence of potassium 2,5-dioxoimidazolidin-1-ide

2021 ◽  
Vol 25 ◽  
Author(s):  
Neda Reihani ◽  
Hamzeh Kiyani
Keyword(s):  
Ethylene Glycol ◽  
Ethyl Acetoacetate ◽  
Reaction Medium ◽  
Hydroxylamine Hydrochloride ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
Efficient Synthesis ◽  
Current Process ◽  
High Yields ◽  
Low Catalyst Loading

: An efficient synthesis of 4-arylidene-3-alkylisoxazole-5(4H)-ones has been implemented via the three-component cyclocondensation of aryl(heteroaryl)aldehydes with hydroxylamine hydrochloride and β-ketoesters. The potassium 2,5-dioxoimidazolidin-1-ide has been introduced as the new organocatalyst to facilitate of this heterocyclization. In the current process, three starting materials, including substituted benzaldehydes/heterocyclic aromatic aldehydes, hydroxylamine hydrochloride, and ethyl acetoacetate/propyl acetoacetate/butyryl acetoacetate have been successfully used for the synthesize of the number of substituted isoxazole-5(4H)-ones in good to high yields in ethylene glycol as a green reaction medium at 80 ºC. The low catalyst loading is also a main advantage over the some reported catalysts.

scholarly journals Synthesis of pyrimidines by Fe3O4@SiO2-L-proline nanoparticles

2020 ◽  
Vol 43 (1) ◽  
pp. 117-124
Author(s):  
Javad Safaei-Ghomi ◽  
Zahra Samadi
Keyword(s):  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
High Yields ◽  
Low Catalyst Loading ◽  
Ft Ir Spectroscopy

AbstractFe3O4@SiO2-L-proline nanoparticles have been used as an effective catalyst for the preparation of pyrimidines by three-component reactions of 1,3-dimethylbarbituric acid, aromatic aldehydes and 4-methyl aniline or 4-methoxy aniline under reflux condition in ethanol. Fe3O4@SiO2-L-proline nanoparticles have been characterized by scanning electronic microscopy (SEM), powder X-ray diffraction (XRD), vibrating sample magnetometer (VSM), thermal gravimetric analysis (TGA), energy dispersive X-ray (EDS), dynamic light scattering (DLS) and FT-IR spectroscopy. This method provides several advantages including, the reusability of the catalyst, low catalyst loading, atom economy, short reaction times and high yields of products.

scholarly journals Enantioselective Au(I)-Catalyzed Multicomponent Annulation via Tethered Counterion-Directed Catalysis

2021 ◽  
Author(s):  
Zhenhao Zhang ◽  
Nazarii Sabat ◽  
Gilles Frison ◽  
Angela Marinetti ◽  
Xavier GUINCHARD
Keyword(s):  
Phosphoric Acid ◽  
Dft Calculations ◽  
Multicomponent Reaction ◽  
Multicomponent Reactions ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
Broad Scope ◽  
Chiral Phosphoric Acid ◽  
High Yields ◽  
Low Catalyst Loading

Gold(I) complexes of a new chiral phosphoric acid functionalized phosphine of the CPA-Phos series enable the enantioselective multicomponent reactions between aldehydes, hydroxylamines and cyclic yne-enones, leading to 3,4-dihydro-1H-furo[3,4-d][1,2]oxazines. This represents the first example of highly enantioselective multicomponent reaction in gold(I) catalysis. The reactions proceed at low catalyst loading, provide high yields, total diastereoselectivity and enantiomeric excesses up to 99%. Silver-free conditions can be applied. The method has a very broad scope, as it applies to both aliphatic and aromatic aldehydes and hydroxylamines, to a variety of cyclic yne-enones, as well as to yne-enone derived oximes. DFT calculations are reported that enlighten the enantiocontrol pathway.

Tin(II)chloride Mediated Addition Reaction of Bromonitromethane to Aldehydes

2005 ◽  
Vol 60 (4) ◽  
pp. 416-418 ◽  
Author(s):  
Ali S. Mahasneh
Keyword(s):  
Mass Spectroscopy ◽  
Elemental Analysis ◽  
Addition Reaction ◽  
Aromatic Aldehydes ◽  
Aliphatic Aldehydes ◽  
Type Reaction ◽  
High Yields

Bromonitromethane adds to aliphatic aldehydes in the presence of tin(II) chloride to yield β -nitro alcohols via a Reformatsky-type reaction in high yields, while aromatic aldehydes give low yields. The products were characterized by IR, NMR, and mass spectroscopy and by elemental analysis

SiO2·12WO3·24H2O: a Highly Efficient Catalyst for the Synthesis of 5-Arylidene Barbituric Acid in the Presence of Water

2009 ◽  
Vol 62 (4) ◽  
pp. 353 ◽  
Author(s):  
Ji-Tai Li ◽  
Ming-Xuan Sun
Keyword(s):  
Room Temperature ◽  
Barbituric Acid ◽  
Aqueous Media ◽  
Aromatic Aldehydes ◽  
Efficient Catalyst ◽  
Highly Efficient ◽  
Efficient Route ◽  
Acid Catalyzed ◽  
High Yields

The condensation of aromatic aldehydes and barbituric acid catalyzed by SiO2·12WO3·24H2O in aqueous media at room temperature gave 5-arylidene barbituric acid in high yields with or without the use of ultrasound, providing a simple and efficient route to synthesis of these compounds.

scholarly journals Enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by binaphthyl-derived organocatalysts

2012 ◽  
Vol 8 ◽  
pp. 699-704 ◽  
Author(s):  
Saet Byeol Woo ◽  
Dae Young Kim
Keyword(s):  
Michael Addition ◽  
Catalyst Loading ◽  
High Yields ◽  
Low Catalyst Loading

The highly enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes, promoted by binaphthyl-modified chiral bifunctional organocatalysts is described. This reaction afforded the chiral functionalized naphthoquinones in high yields (81–95%) and excellent enantioselectivities (91–98% ee) under low catalyst loading (1 mol %).

1,3-Dibromo-5,5-dimethylhydantoin as a useful reagent for efficient synthesis of 3,4-dihydropyrimidin-2-(1H)-ones under solvent-free conditions

2009 ◽  
Vol 63 (1) ◽  
Author(s):  
Mohammad Abdollahi-Alibeik ◽  
Zahra Zaghaghi
Keyword(s):  
Microwave Irradiation ◽  
Ethyl Acetoacetate ◽  
Biginelli Reaction ◽  
Reaction Times ◽  
Solvent Free ◽  
Efficient Synthesis ◽  
One Pot ◽  
Aliphatic Aldehydes ◽  
Solvent Free Conditions ◽  
High Yields

AbstractEfficient syntheses of 3,4-dihydropyrimidin-2-(1H)-ones and the corresponding thioxo derivatives using 1,3-dibromo-5,5-dimethylhydantoin (DBH) catalysis of a one-pot three-component Biginelli reaction of aldehydes, ethyl acetoacetate, and urea or thiourea under microwave irradiation are described. The advantages of this method are its short reaction times, high yields of the products, inexpensive and commercially available catalyst, and solvent-free conditions. Typical isolated yields exceed 70 % for arylaldehydes (9 examples) and aliphatic aldehydes (2 examples).

Potassium Hydroxide Catalysed Intermolecular Aza-Michael Addition of 3-Cyanoindole to Aromatic Enones

Synlett ◽  
2017 ◽  
Vol 28 (10) ◽  
pp. 1227-1231 ◽  
Author(s):  
Jingya Yang ◽  
Tianyuan Li ◽  
Hongyan Zhou ◽  
Nana Li ◽  
Dongtai Xie ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Michael Addition ◽  
Potassium Hydroxide ◽  
Michael Reaction ◽  
Pharmaceutical Compounds ◽  
Catalyst Loading ◽  
Good Substrate ◽  
Substrate Tolerance ◽  
High Yields ◽  
Low Catalyst Loading

Indole is one of the utmost important heterocycles as it is an essential nucleus of many pharmaceutical compounds. Its aza-Michael reaction, however, is underdeveloped because of the moiety’s inherent characteristics. Here, a potassium hydroxide catalysed intermolecular aza-Michael reaction of 3-cyanoindole with aromatic enones is described. A variety of chalcone derivatives are well tolerated and afford the corresponding N-adducts in moderate to high yields. The use of a cheap catalyst, low catalyst loading, mild reaction temperature, and good substrate tolerance make this procedure a direct and facile method for the preparation of N1-functionalized indoles.

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