scholarly journals Iodination of Alkylbenzenes using Benzyltriphenylphosphonium Dichromate / I2 System

2009 ◽  
Vol 6 (4) ◽  
pp. 1164-1166 ◽  
Author(s):  
R. Sathiyapriya ◽  
R. Joel Karunakaran
Keyword(s):  
Rapid Method ◽  
Aromatic Compounds ◽  
Solvent System ◽  
Molecular Iodine ◽  
High Yields ◽  
Alkyl Benzenes

An efficient and rapid method have been found using benzyltriphenylphosphonium dichromate (PhCH2PPh3)2Cr2O7as an oxidant along with molecular iodine for the iodination of aromatic compounds. Iodination of a wide variety of alkyl benzenes were done under dichloromethane solvent system and high yields of iodo products were obtained

I2-Catalyzed Oxidative Coupling of Ketone Oximes and Dialkyl/Diarylphosphine Oxides

Synlett ◽  
2020 ◽  
Vol 32 (01) ◽  
pp. 75-80
Author(s):  
Qingle Zeng ◽  
Nutao Li ◽  
Yiding Wang ◽  
Hongqin Yang ◽  
Ze He
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Coupling ◽  
Molecular Iodine ◽  
Oxidizing Agent ◽  
Atom Economy ◽  
High Yields

AbstractA new protocol for the oxidative coupling of ketone oximes with dialkyl/diarylphosphine oxides to synthesize O-(dialkylphosphinyl)ketone oximes has been developed. Hydrogen peroxide is used as a green oxidizing agent, and molecular iodine is used as a nonmetal catalyst. The reaction has a high atom economy, with water as the only byproduct. O-(Dialkylphosphinyl)ketone oximes with 26 examples have been obtained with high yields. Furthermore, the product may be transformed into other molecules, i.e., by reduction.

A rapid method to produce high yields of purified rotavirus particles

2002 ◽  
Vol 104 (1) ◽  
pp. 9-19 ◽  
Author(s):  
Guillermo Adolfo Villegas ◽  
Marcelo Horacio Argüelles ◽  
Alejandro Andrés Castello ◽  
Neus Jiménez Mas ◽  
Graciela Glikmann
Keyword(s):  
Rapid Method ◽  
High Yields

scholarly journals Friedel-Crafts benzoylation reaction of aromatic compounds using zinc oxide nanoparticles in deep eutectic solvent (choline chloride/urea) under microwave irradiation

2019 ◽  
Vol 2 (2) ◽  
pp. 62-70
Author(s):  
Hai Truong Nguyen ◽  
Dung Thi Kim Ngo ◽  
Thinh Nguyen Huu Pham ◽  
Phuong Hoang Tran
Keyword(s):  
Zinc Oxide ◽  
Microwave Irradiation ◽  
Aromatic Compounds ◽  
Zinc Oxide Nanoparticles ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Reaction Times ◽  
Oxide Nanoparticles ◽  
X Ray ◽  
High Yields

Synthesis of zinc oxide nanoparticles (ZnO) which was found to be effective catalyst for Friedel-Crafts benzoylation reaction in the presence of deep eutectic solvent (DES). The method is one of the most important intermediates for preparing fine chemicals in the field of pharmaceuticals, which is a tool for organic syntheses of aromatic ketones. ZnO precursor was prepared from Zn(CH3COO)2.2H2O and H2C2O4.2H2O, ZnO nanoparticles were characterized by using X-ray Powder Diffraction (XRD), Scanning Electron Microscope (SEM). The benzoylation of aromatic compounds and benzoyl chloride using nanoparticles ZnO/ [CholineCl][Urea]2, under microwave irradiation afforded the desired products in high yields and short reaction times. The catalyst/solvent could be recycled several times without loss of efficient catalytic activity.

scholarly journals Mesoscale Assembly of Bisteroidal Esters from Terephthalic Acid

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1213 ◽  
Author(s):  
Gabriel Guerrero-Luna ◽  
María Guadalupe Hernández-Linares ◽  
Sylvain Bernès ◽  
Alan Carrasco-Carballo ◽  
Diana Montalvo-Guerrero ◽  
...  
Keyword(s):  
Self Assembly ◽  
Terephthalic Acid ◽  
Van Der Waals ◽  
Solvent System ◽  
Van Der Waals Interactions ◽  
Show Evidence ◽  
Non Covalent Interactions ◽  
Solvent Systems ◽  
High Yields ◽  
Covalent Interactions

A new series of bisteroidal esters was synthesized using a spacer group, sterols and sapogenins as substrates. Steroidal dimers were prepared in high yields employing diesters of terephthalic acid as linkages at the 3β, 3′β steroidal positions. In all attempts to crystallize bisteroids, it was observed that the compounds tended to self-organize in solution, which was detected when employing various solvent systems. The non-covalent interactions (van der Waals) of the steroidal moieties of this series of symmetrical bisteroids, the polarity of the solvents systems, and the different solubilities of the bisteroid aggregates, indeed induce the molecules to self-assemble into supramolecular structures with well-defined organization. Our results show that the self-assembled structures for the bisteroidal derivatives depend on the solvent system used: with hexane/EtOAc, membrane-shaped structures were obtained, while pure EtOAc afforded strand-shaped arrangements. In the CHCl3/CH3OH system, thin strands were formed, since van der Waals interactions are lowered in this system, as a consequence of the increased solubility of the bisteroids in CHCl3. Based on the characterization by SEM and XRD, we show evidence that the phenomenon of self-assembly of bisteroids occurs presenting different morphologies depending on the solvent used. The new steroidal dimer derivatives were characterized by NMR, TGA, DSC, SEM, and XRD. Finally, the molecular structure of one bisteroid was confirmed by single-crystal X-ray analysis.

Dimerization of Aromatic Compounds Using Palladium-Carbon-Catalyzed Suzuki–Miyaura Cross-Coupling by One-Pot Synthesis

Synlett ◽  
2018 ◽  
Vol 29 (06) ◽  
pp. 779-784 ◽  
Author(s):  
Guoliang Chen ◽  
Fangyu Du ◽  
Qifan Zhou ◽  
Dongdong Liu ◽  
Ting Fang ◽  
...  
Keyword(s):  
Aromatic Compounds ◽  
Functional Group ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Potassium Acetate ◽  
Carbon Catalyst ◽  
Reaction Conditions ◽  
One Pot ◽  
Cross Coupling Reaction ◽  
High Yields

The aromatic dimers play a significant role in many aspects. Herein, we report a simple palladium-carbon catalyst that is highly effective for the dimerization of brominated aromatic compounds under mild conditions using abundant brominated aromatic compounds, bis(pinacolate)diboron and potassium acetate by a ‘one-pot’ method. This process, which we believe proceeds via a Suzuki–Miyaura cross-coupling reaction mechanism, allows access to a variety of aromatic compounds under mild reaction conditions and has a good functional group tolerance with moderate to high yields.

scholarly journals Transcriptomic Assessment of Isozymes in the Biphenyl Pathway of Rhodococcus sp. Strain RHA1

2006 ◽  
Vol 72 (9) ◽  
pp. 6183-6193 ◽  
Author(s):  
Edmilson R. Gon�alves ◽  
Hirofumi Hara ◽  
Daisuke Miyazawa ◽  
Julian E. Davies ◽  
Lindsay D. Eltis ◽  
...  
Keyword(s):  
Dna Microarray ◽  
Aromatic Compounds ◽  
Regulatory Mechanism ◽  
Sequence Analyses ◽  
Catabolic Enzymes ◽  
Catabolic Genes ◽  
Genes Encoding ◽  
Pcr Assays ◽  
Alkyl Benzenes ◽  
Rhodococcus Sp

ABSTRACT Rhodococcus sp. RHA1 grows on a broad range of aromatic compounds and vigorously degrades polychlorinated biphenyls (PCBs). Previous work identified RHA1 genes encoding multiple isozymes for most of the seven steps of the biphenyl (BPH) pathway, provided evidence for coexpression of some of these isozymes, and indicated the involvement of some of these enzymes in the degradation of BPH, ethylbenzene (ETB), and PCBs. To investigate the expression of these isozymes and better understand how they contribute to the robust degradative capacity of RHA1, we comprehensively analyzed the 9.7-Mb genome of RHA1 for BPH pathway genes and characterized the transcriptome of RHA1 growing on benzoate (BEN), BPH, and ETB. Sequence analyses revealed 54 potential BPH pathway genes, including 28 not previously reported. Transcriptomic analysis with a DNA microarray containing 70-mer probes for 8,213 RHA1 genes revealed a suite of 320 genes of diverse functions that were upregulated during growth both on BPH and on ETB, relative to growth on the control substrate, pyruvate. By contrast, only 65 genes were upregulated during growth on BEN. Quantitative PCR assays confirmed microarray results for selected genes and indicated that some of the catabolic genes were upregulated over 10,000-fold. Our analysis suggests that up to 22 enzymes, including 8 newly identified ones, may function in the BPH pathway of RHA1. The relative expression levels of catabolic genes did not differ for BPH and ETB, suggesting a common regulatory mechanism. This study delineated a suite of catabolic enzymes for biphenyl and alkyl-benzenes in RHA1, which is larger than previously recognized and which may serve as a model for catabolism in other environmentally important bacteria having large genomes.

A Simple and Rapid Method for Determination of Guayule Rubber

1986 ◽  
Vol 59 (2) ◽  
pp. 204-207 ◽  
Author(s):  
Sarina Grinberg ◽  
Eleonora Shaubi
Keyword(s):  
Rapid Method ◽  
Analytical Method ◽  
Aromatic Compounds ◽  
Turbidimetric Assay ◽  
Protection Agent

Abstract An improved turbidimetric analytical method for guayule rubber was developed. The method is simpler and faster than previously developed turbidimetric methods, and enables the use of commercial solutions of the rubber. Unlike Traub and Perry, who used diisobutyl ketone for extraction of guayule rubber for turbidimetric measurements, we used hexane, which did not extract aromatic compounds along with the rubber, thus giving the best yield of spectrally clean rubber. Propanol is our precipitant of choice for turbidimetric assay of rubber, since it is also good as a colloid-protection agent.

Coupling metal halides with a co-solvent to produce furfural and 5-HMF at high yields directly from lignocellulosic biomass as an integrated biofuels strategy

2014 ◽  
Vol 16 (8) ◽  
pp. 3819-3829 ◽  
Author(s):  
Charles M. Cai ◽  
Nikhil Nagane ◽  
Rajeev Kumar ◽  
Charles E. Wyman
Keyword(s):  
Lignocellulosic Biomass ◽  
Solvent System ◽  
Metal Halides ◽  
High Yields

A monophasic reaction strategy is proposed that couples metal halides with a highly tunable co-solvent system employing renewable THF to significantly enhance co-production of furfural and 5-HMF from biomass.

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