scholarly journals Cyanuric Chloride as an Efficient Catalyst for the Synthesis of 2,3-UnsaturatedO-Glycosides by Ferrier Rearrangement

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
Xiaojuan Yang ◽  
Na Li
Keyword(s):  
Room Temperature ◽  
Cyanuric Chloride ◽  
Efficient Catalyst ◽  
Experimental Procedure ◽  
Wide Range ◽  
Ferrier Rearrangement ◽  
High Yields

Cyanuric chloride has been found to be an efficient catalyst for the synthesis of 2,3-unsaturatedO-glycosides from the reaction of 3,4,6-tri-O-acetyl-D-glucal and a wide range of alcohols in dichloromethane at room temperature. The experimental procedure is simple, and the products are obtained in high yields.

Michael Addition of Aryl Thiols to 3-(2,2,2-Trifluoroethylidene)Oxindoles under Catalyst-Free Conditions: The Rapid Synthesis of Sulfur-Containing Oxindole Derivatives

2018 ◽  
Vol 42 (4) ◽  
pp. 210-214
Author(s):  
Bo Chen ◽  
Jiaheng Lei ◽  
Junling Zhao
Keyword(s):  
Michael Addition ◽  
Room Temperature ◽  
Rapid Synthesis ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
Catalyst Free ◽  
Wide Range ◽  
High Yields ◽  
The Michael Addition ◽  
Sulfur Containing

A mild and efficient catalyst-free method for the rapid synthesis at room temperature of 3-thiomethylated oxindole derivatives has been achieved via the Michael addition of aryl thiols to ring and 1-substituted 3-(2,2,2-trifluoroethylidene)oxindoles in dichloromethane. The method was applicable to a wide range of thiols and variously substituted 3-(2,2,2-trifluoroethylidene)oxindoles under mild conditions as demonstrated by the synthesis in high yields with good diastereoselectivities of 30 3-thiomethylated oxindoles bearing a trifluoromethyl group.

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.

An operationally simple green procedure for the synthesis of dihydropyrimido[4,5-d]pyrimidinetriones using CuI nanoparticles as a highly efficient catalyst

2015 ◽  
Vol 70 (3) ◽  
pp. 171-176 ◽  
Author(s):  
Shahrzad Abdolmohammadi ◽  
Maryam Afsharpour
Keyword(s):  
Room Temperature ◽  
Aqueous Media ◽  
Coupling Reaction ◽  
Aromatic Aldehydes ◽  
Significant Loss ◽  
Efficient Catalyst ◽  
Nano Crystalline ◽  
Simple Protocol ◽  
High Yields ◽  
Green Procedure

AbstractA green, efficient and simple protocol was developed for the synthesis of dihydropyrimido[4,5-d]pyrimidinetrione derivatives via a coupling reaction of 6-aminouracils, aromatic aldehydes and urea in aqueous media in the presence of nano-crystalline CuI at room temperature. The products were obtained in high yields. CuI nanoparticles can be recycled three times without significant loss of catalytic activity.

Activated Carbon/MoO3: Efficient Catalyst for Green Synthesis of Chromeno[d]pyrimidinediones and Xanthenones

2020 ◽  
Vol 23 ◽  
Author(s):  
Niloofar Sabet Mehr ◽  
Shahrzad Abdolmohammadi ◽  
Maryam Afsharpour
Keyword(s):  
Activated Carbon ◽  
Room Temperature ◽  
Bulk Material ◽  
Biological Activities ◽  
Reaction Times ◽  
Aromatic Aldehydes ◽  
Biologically Active ◽  
Efficient Catalyst ◽  
Calcium Blockers ◽  
High Yields

Background: Nanoscale metal oxide catalysts have been extensively employed in organic reactions because they have been found to influence the chemical and physical properties of the bulk material. The chromene (benzopyran) nucleus constitutes the core structure in a major class of many biologically active compounds, and interest in their chemistry consequently continues because of their numerous biological activities. The xanthene (dibenzopyran) derivatives are classified as highly significant compounds which display a number of various bioactive properties. Pyrimidinones have also gained interest due to their remarkable biological utilization such as antiviral, antibacterial, antihypertensive, antitumor and calcium blockers effects. Objective: Our aim in the work presented herein was to prepare activated carbon/MoO3 nanocomposite and explore its role as a green and recyclable catalyst for the synthesis of chromeno[d]pyrimidinediones and xanthenones under ethanol-drop grinding at room temperature. Methods: The activated carbon/MoO3 nanocomposite was prepared successfully via a simple route in which carbonization of gums as new natural precursors was used for the synthesis of activated carbon. This nanocomposite was then effectively used in a reaction of 3,4- methylenedioxyphenol, aromatic aldehydes and active methylene compounds including 1,3-dimethylbarbituric acid and dimedone to synthesize a series of chromeno[d]pyrimidinediones and xanthenones in high yields. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), Powder x-ray diffractometry (XRD), Scanning electron microscope (SEM), Raman spectroscopy, and also by TGA analysis. Confirmation of the structures of compounds 5(a-g) and 6(a-g) were also established with IR, 1 H NMR and 13C NMR spectroscopic data and also by elemental analyses. Results: A number of 6,8-dimethyl-10-phenyl-6,10-dihydro-7H-[1,3]dioxolo[4΄,5΄:6,7]chromeno[2,3-d]pyrimidine-7,9(8H)-diones and 7,7- dimethyl-10-(4-methylphenyl)-6,7,8,10-tetrahydro-9H-[1,3]dioxolo[4,5-b]xanthen-9-ones were effectively synthesized using activated carbon/MoO3 nanocomposite (0.05 gr) as catalyst under ethanol-drop grinding at room temperature. The desired products were obtained in high yields (93-97%) within short reaction times (15-20 min). Conclusion: This paper investigates the catalytic potential of the synthesized activated carbon/MoO3 nanocomposite for the prepataion of chromeno[d]pyrimidinediones and xanthenones under ethanol-drop grinding procedure. The mildness of the reaction conditions, high yields of products, short reaction times, experimental simplicity, and avoid the use of harmful solvents or reagents makes this procedure preferable for the synthesis of these compounds.

Iodosulfonation of alkenes with benzenesulfinic acid – N-iodosuccinimide — Facile preparation of α,β-unsaturated sulfones

2006 ◽  
Vol 84 (4) ◽  
pp. 667-675 ◽  
Author(s):  
Russell R Wolff ◽  
Vikram Basava ◽  
Robert M Giuliano ◽  
Walter J Boyko ◽  
J Herman Schauble
Keyword(s):  
Room Temperature ◽  
High Yield ◽  
Allylic Alcohols ◽  
Neutral Alumina ◽  
Silyl Ethers ◽  
Step Procedure ◽  
Ferrier Rearrangement ◽  
Facile Preparation ◽  
High Yields ◽  
Yield And Purity

Reaction of alkenes and alkenols with N-iodosuccinimide (NIS) and benzenesulfinic acid in dichloromethane at room temperature affords vic-iodophenylsulfonyl adducts in good to high yields. Treatment of the iodosulfones with neutral alumina in dichloromethane at room temperature results in dehydroiodination to give the corresponding vinyl sulfones in high yield and purity by this convenient two-step procedure. Application of the iodosulfonation–dehydroiodination sequence to allylic alcohols and silyl ethers gave γ-oxygenated, α,β-unsaturated phenylsulfones, while the attempted iodosulfonation of glycals, as intermediates to vinyl sulfones, resulted in addition of benzenesulfinic acid with double bond shift (Ferrier rearrangement). Key words: iodosulfonation, vinyl sulfones, benzenesulfinic acid, N-iodosuccinimide, dehydroiodination.

scholarly journals Copper Perchlorate Hexahydrate: An Efficient Catalyst for the Green Synthesis of Polyhydroquinolines under Ultrasonication

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Saurabh Puri ◽  
Balbir Kaur ◽  
Anupama Parmar ◽  
Harish Kumar
Keyword(s):  
Ethyl Acetoacetate ◽  
Room Temperature ◽  
Ammonium Acetate ◽  
Condensation Reaction ◽  
Reaction Times ◽  
Ultrasound Irradiation ◽  
Synthetic Method ◽  
Efficient Catalyst ◽  
High Yields ◽  
Perchlorate Hexahydrate

Copper perchlorate hexahydrate as an efficient catalyst was used for the synthesis of polyhydroquinolines by four-component condensation reaction of aldehyde, ethyl acetoacetate, dimedone, and ammonium acetate in excellent yields and short reaction times at room temperature under ultrasound irradiation. This novel synthetic method is especially favoured because it provides a synergy between copper perchlorate hexahydrate and ultrasound irradiation which offers the advantages of high yields, short reaction times, simplicity, and easy workup compared to the conventional methods reported in the literature.

scholarly journals SbCl3-Catalyzed conversion of ketones and aldehydes into gem-dihydroperoxides (DHPs) with 30% H2O2

2015 ◽  
Vol 11 (5) ◽  
pp. 3547-3553 ◽  
Author(s):  
Davood Azarifar ◽  
Boshra Mahmoudi ◽  
Kaveh Khosravi
Keyword(s):  
Present Method ◽  
Room Temperature ◽  
Reaction Times ◽  
Experimental Procedure ◽  
Mild Conditions ◽  
Efficient Conversion ◽  
High Yields ◽  
Catalyzed Oxidation

A simple and efficient conversion of ketones and aldehydes into corresponding gem-dihydroperoxides (DHPs) has been developed by SbCl3-catalyzed oxidation with 30% H2O2 at room temperature. The reactions proceeded smoothly under mild conditions at room temperature. Simple experimental procedure, use of inexpensive and non-toxic catalyst, high yields and low reaction times are the main merits of the present method.

A simple, highly regioselective and efficient reaction of indole with epoxides under solvent-free conditions

2006 ◽  
Vol 84 (5) ◽  
pp. 800-803 ◽  
Author(s):  
Najmedin Azizi ◽  
Shokopheh Mehrazma ◽  
Mohammad R Saidi
Keyword(s):  
Carbon Atom ◽  
Styrene Oxide ◽  
Lithium Perchlorate ◽  
Solvent Free ◽  
Nucleophilic Attack ◽  
Efficient Catalyst ◽  
Experimental Procedure ◽  
Solvent Free Conditions ◽  
Ring Opening Of Epoxides ◽  
High Yields

Lithium perchlorate has been found to be an inexpensive and efficient catalyst for the ring opening of epoxides by indole and N-methylindole, which provides an environmentally friendly method for the synthesis of substituted indoles. A complete regioselectivity in favor of nucleophilic attack at the benzylic carbon atom of aromatic epoxides, such as styrene oxide, is observed. However, aliphatic unsymmetrical alkene oxides undergo selective nucleophilic attack at the sterically less-hindered carbon atom. This catalyst offers several advantages, such as short reaction time, high yields, lower catalytic loading, simple experimental procedure, and easy isolation of the products, under solvent-free conditions.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Evaluation of 99mTc-Label led Vitamin K4 as an Agent for Testicular Imaging

1991 ◽  
Vol 30 (01) ◽  
pp. 35-39 ◽  
Author(s):  
H. S. Durak ◽  
M. Kitapgi ◽  
B. E. Caner ◽  
R. Senekowitsch ◽  
M. T. Ercan
Keyword(s):  
Soft Tissue ◽  
Room Temperature ◽  
Normal Subjects ◽  
Left Testis ◽  
Wide Range ◽  
Activity Ratios ◽  
The Right ◽  
Radioactivity Levels

Vitamin K4 was labelled with 99mTc with an efficiency higher than 97%. The compound was stable up to 24 h at room temperature, and its biodistribution in NMRI mice indicated its in vivo stability. Blood radioactivity levels were high over a wide range. 10% of the injected activity remained in blood after 24 h. Excretion was mostly via kidneys. Only the liver and kidneys concentrated appreciable amounts of radioactivity. Testis/soft tissue ratios were 1.4 and 1.57 at 6 and 24 h, respectively. Testis/blood ratios were lower than 1. In vitro studies with mouse blood indicated that 33.9 ±9.6% of the radioactivity was associated with RBCs; it was washed out almost completely with saline. Protein binding was 28.7 ±6.3% as determined by TCA precipitation. Blood clearance of 99mTc-l<4 in normal subjects showed a slow decrease of radioactivity, reaching a plateau after 16 h at 20% of the injected activity. In scintigraphic images in men the testes could be well visualized. The right/left testis ratio was 1.08 ±0.13. Testis/soft tissue and testis/blood activity ratios were highest at 3 h. These ratios were higher than those obtained with pertechnetate at 20 min post injection.99mTc-l<4 appears to be a promising radiopharmaceutical for the scintigraphic visualization of testes.

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