The enantioselective trifluoromethylation of aromatic aldehydes by quaternary ammonium bromide and (IPr)CuF at low catalyst loading

2013 ◽  
Vol 148 ◽  
pp. 19-29 ◽  
Author(s):  
Shaoxiang Wu ◽  
Jiyi Guo ◽  
Muhammad Sohail ◽  
Chengyao Cao ◽  
Fu-Xue Chen
Keyword(s):  
Quaternary Ammonium ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
Ammonium Bromide ◽  
Low Catalyst Loading

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.

scholarly journals Cobalt(II) Chloride Hexahydrate as an Efficient and Inexpensive Catalyst for the Preparation of Biscoumarin Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Mohammad Reza Nazarifar
Keyword(s):  
Aqueous Media ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Catalyst Loading ◽  
One Pot ◽  
Efficient Catalyst ◽  
Chloride Hexahydrate ◽  
The One ◽  
Low Catalyst Loading ◽  
Electron Donating Groups

Cobalt(II) chloride hexahydrate (CoCl2·6H2O) has been found to be an efficient catalyst for the one-pot synthesis of biscoumarin derivatives through a combination of aromatic aldehydes and 4-hydroxycoumarin in aqueous media at 70°C. Several types of aromatic aldehyde, containing electron-withdrawing groups as well as electron-donating groups, were used in the reaction and in all cases the desired products were synthesized successfully. The present approach offers remarkable advantages such as short reaction times, excellent yields, straightforward procedure, easy purification, environment friendliness, and low catalyst loading.

Nano-NiZr4(PO4)6 as a superior catalyst for the synthesis of propargylamines under ultrasound irradiation

2018 ◽  
Vol 73 (3-4) ◽  
pp. 185-189 ◽  
Author(s):  
Hossein Shahbazi-Alavi ◽  
Seyed Hadi Nazemzadeh ◽  
Abolfazl Ziarati ◽  
Javad Safaei-Ghomi
Keyword(s):  
Rapid Method ◽  
Aromatic Aldehydes ◽  
Ultrasound Irradiation ◽  
Catalyst Loading ◽  
Atom Economy ◽  
Three Component Reaction ◽  
Wide Range ◽  
Low Catalyst Loading ◽  
Short Times

AbstractAn easy and rapid method for the synthesis of propargylamines has been achieved through a three-component reaction of phenylacetylene, aromatic aldehydes, and morpholine or piperidine using nano-NiZr4(PO4)6under ultrasound irradiation. Atom economy, a wide range of products, excellent yields in short times, reusability of the catalyst, and low catalyst loading are some of the important features of this protocol.

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.

Synthesis of 2,4-diamino-6-aryl-5-pyrimidinecarbonitrile promoted by amino-functionalized CoFe2O4@SiO2 nanoparticles under conventional heating, microwave and ultrasound irradiations

2018 ◽  
Vol 73 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Samaneh Barkhordarion-Mohammadi ◽  
Javad Safaei-Ghomi
Keyword(s):  
Guanidine Hydrochloride ◽  
Aromatic Aldehydes ◽  
Sio2 Nanoparticles ◽  
Conventional Heating ◽  
Catalyst Loading ◽  
Reaction Conditions ◽  
One Pot ◽  
Efficient Catalyst ◽  
The One ◽  
Low Catalyst Loading

AbstractAmino-functionalized CoFe2O4@SiO2 nanoparticles have been used as an efficient catalyst for the preparation of 2,4-diamino-6-arylpyrimidine-5-carbonitrile derivatives by the one-pot reaction of aromatic aldehydes, malononitrile, and guanidine hydrochloride under conventional heating, microwave, and ultrasound irradiations. This method provides several advantages including mild reaction conditions, the reusability of the catalyst and low catalyst loading, and the use of microwave and ultrasonic irradiation as a valuable and powerful tool.

Y(OTf)3-catalyzed Phosphorylation of 2H-Chromene Hemiacetals with P(O)-H compounds to 2-Phosphorylated 2H-Chromenes

2021 ◽  
Author(s):  
Long Chen ◽  
Shi-Lu Zheng ◽  
Yun-Xiang Zou ◽  
Zhong Wen ◽  
Jiafu Lin ◽  
...  
Keyword(s):  
Catalyst Loading ◽  
Facile Synthesis ◽  
Reaction Conditions ◽  
Low Catalyst Loading

Facile synthesis of 2-phosphorylated 2H-chromenes has been accomplished herein via a Y(OTf)3-catalyzed dehydrative coupling of 2H-chromene hemiacetals with P(O)-H compounds. This protocol features low catalyst loading, mild reaction conditions, broad...

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