Silica-supported ZnCl2 — A highly active and reusable heterogeneous catalyst for the one-pot synthesis of dihydropyrimidinones–thiones

2007 ◽  
Vol 85 (3) ◽  
pp. 197-201 ◽  
Author(s):  
Raman Gupta ◽  
Monika Gupta ◽  
Satya Paul ◽  
Rajive Gupta
Keyword(s):  
Zinc Chloride ◽  
Biginelli Reaction ◽  
Catalyst Loading ◽  
Reaction Conditions ◽  
One Pot ◽  
Highly Active ◽  
Chloride Catalyst ◽  
Biginelli Compounds ◽  
The One ◽  
Low Catalyst Loading

A novel silica-supported zinc chloride catalyst was prepared and investigated for the Biginelli reaction. The key features of the catalyst include rapid reaction with 100% conversion of aldehyde, good catalyst recyclability, and high stability under the reaction conditions (passes hot filtration test successfully). A low catalyst loading (12 mol% of ZnCl2) was required to achieve a quantitative reaction. Other catalysts such as SiO2–AlCl2, SiO2–AlCl2–ZnCl2 were also prepared and their activity was compared with SiO2–ZnCl2 for the Biginelli reaction.Key words: silica gel, zinc chloride, Biginelli compounds, heterogeneous catalysis, reusability.

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.

2-Phenyl-2,3-dihydrobenzo[d]thiazole: A Mild, Efficient, and Highly Active in situ Generated Chemoselective Reducing Agent for the One-Pot Synthesis of 5-Monoalkylbarbiturates in Water

Synlett ◽  
2017 ◽  
Vol 29 (04) ◽  
pp. 477-482 ◽  
Author(s):  
Dibakar Deka ◽  
Subarna Kalita
Keyword(s):  
Reducing Agent ◽  
High Yield ◽  
Purification Process ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Highly Active ◽  
The One ◽  
Operational Simplicity

A metal- and catalyst-free reductive alkylation protocol for the one-pot synthesis of 5-monoalkylbarbiturates from barbituric acids and aldehydes using the in situ generated chemoselective reducing agent 2-phenyl-2,3-dihydrobenzo[d]thiazole from 2-aminothiophenol and benzaldehyde is described. The notable advantages of the protocol are operational simplicity, mild reaction conditions, high yield, short reaction time, and simple workup and purification process which make it highly attractive.

Chiral α-substituted allylboronates in a one-pot three-component asymmetric allylic alkylation/carbonyl allylation reaction sequence — Applications to the syntheses of (+)-(3R,5R)-3-hydroxy-5-decanolide and (–)-massoialactone

2009 ◽  
Vol 87 (5) ◽  
pp. 650-661 ◽  
Author(s):  
Lisa Carosi ◽  
Dennis G. Hall
Keyword(s):  
Alkyl Substituent ◽  
Catalyst Loading ◽  
Allylic Alkylation ◽  
One Pot ◽  
Sequential Reaction ◽  
Three Component Reaction ◽  
Carbonyl Allylation ◽  
The One ◽  
Low Catalyst Loading ◽  
Very High

The use of different organomagnesium reagents in the copper-catalyzed allylic alkylation of 3-chloropropenyl boronates with chiral phosphoramidite ligands produces the desired α-substituted allylic boronate reagents in high regioselectivity and with modest to high enantioselectivities (up to 96% ee). The size of the incoming alkyl substituent from the organomagnesium reagent was found to impact the yield and selectivity of the allylic alkylation. A one-pot procedure for the preparation of these chiral allylic boronates followed by a Lewis acid (BF3) catalyzed addition to aldehydes delivers the desired allylboration products, homoallylic secondary alcohols, in good yields and very high diastereoselectivity. This three-component reaction methodology was applied to the syntheses of two lactone-containing natural products, (–)-massoialactone and (+)-(3R,5R)-3-hydroxy-5-decanolide. The key step of these syntheses involved the one-pot enantioselective copper-catalyzed allylic alkylation/allylboration reaction with a benzylic aldehyde, and afforded the desired product in 87% yield, 92% ee, and high E/Z selectivity in a ratio of 22:1. Remarkably, the allylic alkylation step of this sequential reaction was performed with a low catalyst loading of 2 mol% on a scale of >15 mmol that can provide multiple grams of the three-component product.

A Simple and efficient Synthesis of 3,4-Dihydropyrimidin-2-Ones catalysed by Amidosulfonic Acid

2002 ◽  
Vol 2002 (1) ◽  
pp. 37-39 ◽  
Author(s):  
Tongshou Jin ◽  
Suling Zhang ◽  
Suyun Zhang ◽  
Junjie Guo ◽  
Tongshuang Li
Keyword(s):  
Biginelli Reaction ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
The One ◽  
Better Than

A general and practical route for the synthesis of dihydropyrimidines by the one-pot cyclocondensation of aldehydes, β-ketoesters and urea is described using NH2SO3H as catalyst. Yields and selectivities are significantly better than under classical Biginelli reaction conditions.

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.

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...

Vegetable oil as a highly effective 100% bio-based alternative solvent for the one-pot multicomponent Biginelli reaction

2021 ◽  
Author(s):  
Pakin Noppawan ◽  
Suwiwat Sangon ◽  
Nontipa Supanchaiyamat ◽  
Andrew J. Hunt
Keyword(s):  
Vegetable Oil ◽  
Palm Oil ◽  
Biginelli Reaction ◽  
Environmentally Friendly ◽  
One Pot ◽  
Highly Effective ◽  
The One ◽  
Biginelli Reactions

Multicomponent one-pot Biginelli reactions have been successfully performed using vegetable oil as bio-based, non-toxic, and environmentally friendly solvents. Palm oil was demonstrated to be a highly effective greener solvent as...

Acceleration of Baylis-Hillman reaction using ionic liquid supported organocatalyst

2021 ◽  
Vol 08 ◽  
Author(s):  
Vivek Srivastava
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Catalyst Loading ◽  
Catalyst Recycling ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Highly Active ◽  
Low Catalyst Loading

Background: Baylis-Hillman reaction suffers from the requirement of cheap starting materials, easy reaction protocol, possibility to create the chiral center in the reaction product has increased the synthetic efficacy of this reaction, and high catalyst loading, low reaction rate, and poor yield. Objective: The extensive use of various functional or non-functional ionic liquids (ILs) with organocatalyst increases the reaction rate of various organic transformations as a reaction medium and as a support to anchor the catalysts. Methods: In this manuscript, we have demonstrated the synthesis of quinuclidine-supported trimethylamine-based functionalized ionic liquid as a catalyst for the Baylis-Hillman reaction. Results: We obtained the Baylis-Hillman adducts in good, isolated yield, low catalyst loading, short reaction time, broad substrate scope, accessible product, and catalyst recycling. N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide was also successfully synthesized using CATALYST-3 promoted Baylis-Hillman reaction. Conclusion: We successfully isolated the 25 types of Baylis-Hillman adducts using three different quinuclidine-supported ammonium-based ionic liquids such as Et3AmQ][BF4] (CATALYST-1), [Et3AmQ][PF6] (CATALYST-2), and [TMAAmEQ][NTf2](CATALYST-3) as new and efficient catalysts. Tedious and highly active N-((E,3S,4R)-5-benzylidene-tetrahydro-4-hydroxy-6-oxo-2H-pyran-3-yl) palmitamide derivative was also synthesized using CATALYST-3 followed by Baylis-Hillman reaction. Generally, all the responses demonstrated higher activity and yielded high competition with various previously reported homogenous and heterogeneous Catalytic systems. Easy catalyst and product recovery followed by six catalysts recycling were the added advantages of the prosed catalytic system.

scholarly journals Unravelling the one-pot conversion of biomass-derived furfural and levulinic acid to 1,4-pentanediol catalysed by supported RANEY® Ni–Sn alloy catalysts

RSC Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 241-250
Author(s):  
Rodiansono ◽  
Maria Dewi Astuti ◽  
Kamilia Mustikasari ◽  
Sadang Husain ◽  
Fathur Razi Ansyah ◽  
...  
Keyword(s):  
Levulinic Acid ◽  
Reaction Conditions ◽  
One Pot ◽  
The One ◽  
Alloy Catalysts

The RANEY® Ni–Sn(x) alloy catalysed the one-pot conversion of biomass-derived furfural and levulinic acid to allow remarkable yield of 1,4-pentanediol (up to 90%) under the mild reaction conditions.

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