Water-Assisted Organocatalysis: An Enantioselective Green Protocol for the Henry Reaction

2013 ◽  
Vol 66 (6) ◽  
pp. 661 ◽  
Author(s):  
Prashant B. Thorat ◽  
Santosh V. Goswami ◽  
Wamanrao N. Jadhav ◽  
Sudhakar R. Bhusare
Keyword(s):  
Hydrogen Bonding ◽  
Room Temperature ◽  
Enantioselective Synthesis ◽  
Henry Reaction ◽  
Reaction Conditions ◽  
Green Protocol ◽  
Excellent Yield ◽  
Water As Solvent ◽  
Nitroaldol Reaction ◽  
Work Up

We report an enantioselective Henry (nitroaldol) reaction catalysed by an organocatalyst using water as solvent. The enantioselective synthesis of β-nitroalcohols was achieved by using a neutral chiral organocatalyst, through strong hydrogen bonding, which results in the formation of corresponding products in excellent yield and enantioselectivity at room temperature. Other attractive features of the method are the eco-friendly, non-hazardous, and mild reaction conditions, inexpensive catalyst, and simple work up conditions.

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Abdullah Mohamed Asiri ◽  
Afaf Mohamed Abdel Hameed ◽  
Reham R. Awed ◽  
Kamal Usef Sadek
Keyword(s):  
Ambient Temperature ◽  
Environmental Pollution ◽  
Ammonium Nitrate ◽  
Room Temperature ◽  
Catalytic Amount ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Work Up ◽  
Cerium Iv Ammonium Nitrate

AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.

scholarly journals Synthesis of Pyrazolo-Fused 4-Azafluorenones in an Ionic Liquid. Mechanistic Insights by Joint Studies Using DFT Analysis and Mass Spectrometry

Catalysts ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 820
Author(s):  
Efraín Polo ◽  
Valentina Arce-Parada ◽  
Xaviera A. López-Cortés ◽  
Jesús Sánchez-Márquez ◽  
Alejandro Morales-Bayuelo ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Density Functional ◽  
Room Temperature ◽  
Theoretical Study ◽  
Environmentally Benign ◽  
Reaction Conditions ◽  
Conceptual Density Functional Theory ◽  
Functional Theory ◽  
Three Component Reaction ◽  
Work Up

A series of pyrazolo-fused 4-azafluorenones (indeno[1,2-b]pyrazolo[4,3-e]pyridines, IPP) were synthesized via the three-component reaction between arylaldehydes, 3-methyl-1H-pyrazol-5-amine and 1,3-indanedione in an ionic liquid as a catalyst at room temperature. The applied synthetic route has the advantages of easy work-up under mild reaction conditions presenting moderate yields and an environmentally benign procedure. A theoretical study based on conceptual-density functional theory has been done, bond reactivity indices have been calculated and an electrophilic and nucleophilic character of localized orbitals has been determined to analyze the possible electronic mechanisms.

Facile and direct synthesis of symmetrical acid anhydrides using a newly prepared powerful and efficient mixed reagent

2015 ◽  
Vol 69 (3) ◽  
Author(s):  
Hamed Rouhi-Saadabad ◽  
Batool Akhlaghinia
Keyword(s):  
Carboxylic Acids ◽  
Room Temperature ◽  
Low Cost ◽  
Direct Synthesis ◽  
Reaction Conditions ◽  
Experimental Procedure ◽  
Short Reaction Time ◽  
Acid Anhydrides ◽  
Work Up ◽  
Trichloroisocyanuric Acid

AbstractAn efficient mixed reagent for direct synthesis of symmetrical carboxylic anhydrides from carboxylic acids has been prepared. Carboxylic acids are converted to anhydrides using triphenylphosphine/ trichloroisocyanuric acid under mild reaction conditions at room temperature. Short reaction time, excellent yields of products, low cost, availability of reagents, simple experimental procedure, and easy work-up of the products are the main advantages of the presented method.

scholarly journals ZnO-beta zeolite mediated simple and efficient method for the one-pot synthesis of quinoxaline derivatives at room temperature

2010 ◽  
Vol 8 (2) ◽  
pp. 320-325 ◽  
Author(s):  
Santosh Katkar ◽  
Pravinkumar Mohite ◽  
Lakshman Gadekar ◽  
Balasaheb Arbad ◽  
Machhindra Lande
Keyword(s):  
Efficient Method ◽  
Room Temperature ◽  
Environmentally Benign ◽  
Beta Zeolite ◽  
Reaction Conditions ◽  
One Pot ◽  
One Pot Synthesis ◽  
Quinoxaline Derivatives ◽  
The One ◽  
Work Up

AbstractA rapid and an efficient one-pot method for the synthesis of quinoxalines catalysed by ZnO-beta zeolite at room temperature is described. This environmentally benign method provides several advantages over methods that are currently employed such as a simple work-up, mild reaction conditions, good to excellent yields, and a process to recover and reuse the catalyst for several cycles with consistent activity.

Green Photoorganocatalytic Synthesis of Phenols from Arylboronic Acids

Synlett ◽  
2017 ◽  
Vol 29 (10) ◽  
pp. 1324-1328 ◽  
Author(s):  
Christoforos Kokotos ◽  
Ioanna Sideri ◽  
Errika Voutyritsa
Keyword(s):  
Functional Groups ◽  
Room Temperature ◽  
Boronic Acids ◽  
Light Irradiation ◽  
Reaction Conditions ◽  
Arylboronic Acids ◽  
Water As Solvent ◽  
High Yields

A green and cheap protocol for the photocatalytic hydroxylation of arylboronic acids is presented. 2,2-Dimethoxy-2-phenylacetophenone proved to be the best photoinitiator, among a range of organocatalysts in promoting this reaction. This photocatalytic protocol can be expanded into a wide substrate scope of aromatic boronic acids bearing various functional groups, leading to the corresponding phenols in good to high yields under mild reaction conditions, which include water as solvent, light irradiation provided from standard light-bulbs at room temperature.

scholarly journals Electron-deficient pyridinium salts/thiourea cooperative catalyzed O-glycosylation via activation of O-glycosyl trichloroacetimidate donors

2017 ◽  
Vol 13 ◽  
pp. 2385-2395 ◽  
Author(s):  
Mukta Shaw ◽  
Yogesh Kumar ◽  
Rima Thakur ◽  
Amit Kumar
Keyword(s):  
Hydrogen Bonding ◽  
Catalytic System ◽  
Room Temperature ◽  
Pyridinium Salt ◽  
Pyridinium Salts ◽  
Thiourea Derivative ◽  
Reaction Conditions ◽  
Thiourea Derivatives ◽  
Wide Range

The glycosylation of O-glycosyl trichloroacetimidate donors using a synergistic catalytic system of electron-deficient pyridinium salts/aryl thiourea derivatives at room temperature is demonstrated. The acidity of the adduct formed by the 1,2-addition of alcohol to the electron-deficient pyridinium salt is increased in the presence of an aryl thiourea derivative as an hydrogen-bonding cocatalyst. This transformation occurs under mild reaction conditions with a wide range of O-glycosyl trichloroacetimidate donors and glycosyl acceptors to afford the corresponding O-glycosides in moderate to good yields with predictable selectivity. In addition, the optimized method is also utilized for the regioselective O-glycosylation by using a partially protected acceptor.

Trimethylsilyl Chloride Catalyzed Highly Efficient Synthesis of Schiff Bases of Thiazole in Glycerol under Microwave Irradiation

2019 ◽  
Vol 4 (2) ◽  
pp. 109-112
Author(s):  
Mujahed Shaikh ◽  
Ashvini Sonone ◽  
Mazahar Farooqui ◽  
Ayesha Durrani
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Schiff Bases ◽  
Room Temperature ◽  
Environmentally Benign ◽  
Green Solvent ◽  
Efficient Synthesis ◽  
Acidic Catalyst ◽  
Excellent Yield ◽  
Work Up

A green and environmentally benign protocol is developed for the synthesis of Schiff bases of sulphur containing compound by irradiating thiazole and pyrazole aldehyde in glycerol under microwave irradiation at 70 ºC with trimethylsilyl chloride (TMSCl) as a catalyst. The method has advantages such as excellent yield, use of green solvent, easy work-up and most important the reaction completed within 2.5 min by using TMSCl catalyst. The TMSCl is an acidic catalyst, which enhances the yield of product, reaction time (with microwave, with reflux at 75 ºC and with stirring at room temperature) which can be easily removed from reaction mask.

Metal-Free One-Pot Chemoselective Thiocyanation of Imidazothiazoles and 2-Aminothiazoles with in situ Generated N-Thiocyanatosuccinimide

Synlett ◽  
2018 ◽  
Vol 29 (14) ◽  
pp. 1902-1908 ◽  
Author(s):  
Bhaskar Dawane ◽  
Shuddhodan Kadam ◽  
Ajay Ambhore ◽  
Madhav Hebade ◽  
Rahul Kamble ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Electrophilic Substitution ◽  
Room Temperature ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Free ◽  
Excellent Yield

A chemoselective thiocyanation of imidazothiazoles and 2-aminothiazoles with use of in situ generated N-thiocyanatosuccinimide (NTS) at room temperature is described. The protocol offers mild reaction conditions and high chemoselectivity for electrophilic substitution in imidazothiazoles over nucleophilic substitution. This method provides metal-free and easy conversion of imidazothiazoles and 2-aminothiazoles into their corresponding C-3 and C-5 thiocyanates, respectively, in good to excellent yield. The present protocol also offers the effective thiocyanation of bifunctional imidazothiazoles containing ­aliphatic –OH and C(sp2)–H bond functionalities.

scholarly journals Fe3O4@Sap/Cu(ii): an efficient magnetically recoverable green nanocatalyst for the preparation of acridine and quinazoline derivatives in aqueous media at room temperature

RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15989-16003
Author(s):  
Milad Kazemnejadi ◽  
Mohammad Ali Nasseri ◽  
Safoora Sheikh ◽  
Zinat Rezazadeh ◽  
Seyyedeh Ameneh Alavi Gol
Keyword(s):  
Heterogeneous Catalyst ◽  
Room Temperature ◽  
Aqueous Media ◽  
Reaction Conditions ◽  
Green Protocol ◽  
Highly Efficient ◽  
Quinazoline Derivatives ◽  
Efficient Heterogeneous Catalyst

A highly efficient, robust, and green protocol has been developed for the synthesis of acridine and quinazoline derivatives in water under mild reaction conditions using a Fe3O4@Sap/Cu(ii) nanocomposite as an efficient heterogeneous catalyst.

Urea-Catalyzed Functionalization of Unactivated C–H Bonds

2020 ◽  
Author(s):  
Alex L. Bagdasarian ◽  
Stasik Popov ◽  
Benjamin Wigman ◽  
Wenjing Wei ◽  
woojin lee ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Organic Synthesis ◽  
High Energy ◽  
Acid Catalysts ◽  
Potential Utility ◽  
New Paradigm ◽  
Lewis Acid Catalysts ◽  
Reaction Conditions ◽  
Highly Active ◽  
Acidic Nature

Herein we report the 3,5bistrifluoromethylphenyl urea-catalyzed functionalization of unactivated C–H bonds. In this system, the urea catalyst mediates the formation of high-energy vinyl carbocations that undergo facile C–H insertion and Friedel–Crafts reactions. We introduce a new paradigm for these privileged scaffolds where the combination of hydrogen bonding motifs and strong bases affords highly active Lewis acid catalysts capable of ionizing strong C–O bonds. Despite the highly Lewis acidic nature of these catalysts that enables triflate abstraction from sp<sup>2</sup> carbons, these newly found reaction conditions allow for the formation of heterocycles and tolerate highly Lewis basic heteroaromatic substrates. This strategy showcases the potential utility of dicoordinated vinyl carbocations in organic synthesis.<br>

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