Acid catalysts

The efficient synthesis of 12-substituted-3,4,4a,5,12,12a-hexahydrobenzo[b]acridine-1,6,11(2H)-triones starting from 2-amino-1,4-naphthoquinone, 1,3-cyclohexanedione, and different (hetero)aromatic aldehydes was developed. These reactions were carried out in acetic acid under microwave irradiation in the presence of p-toluenesulfonic acid as catalyst. The structure of the newly synthesized compounds were confirmed employing spectroscopic data as well as elemental analysis. The plausible mechanism of these three-component domino reactions was also described.

7p dianmotminh02 03-05-2024 4 1   Download

This study aims to synthesize and characterize the formation of dihydroxystearic acid (DHSA) from the ring opening of epoxidized oleic acid. The optimal reaction parameters to produce DHSA were found using sulfuric acid as catalyst in which the maximum relative conversion was reached up to 86%. The detection of hydroxyl group was using Fourier Transform Infrared Spectroscopy.

6p dianmotminh02 03-05-2024 2 1   Download

Ebook "Transformation of carbon dioxide to formic acid and methanol" explains the principles and fundamentals of carbon dioxide utilization and highlights the transformation to fuels and value-added chemicals such as formic acid and methanol. It is divided into six chapters, including an introduction to the basics of CO2 utilization and transformation of CO2 to formic acid and methanol with homogeneous and heterogeneous catalysts, respectively.

128p tracanhphuonghoa1007 22-04-2024 4 3   Download

In this paper, two fatty acid modified Nmethylol melamine compounds combined with magnesium and aluminium catalysts were investigated on water/moisture related properties of the treated veneers, such as water repellence and radial dimensional stability, equilibrium moisture content and radial swelling.

11p vilarry 01-04-2024 4 1   Download

These reactions involved a condensation reaction of aromatic benzaldehydes, 5,5-dimethyl-1,3-cyclohexanedione, and dicyanomethane in a solvent mixture of ethanol and water, resulting in the desired products in moderate to good yields. The procedure is efficient and eco-friendly, and the products can be easily obtained by recrystallisation. Thus, this protocol offers an alternative to existing methods.

12p viellison 28-03-2024 5 1   Download

Ebook "Amination and formation of sp2 C–N bonds (Topics in Organometallic chemistry, Volume 46)" highlights in the first chapter, written by Lemen and Wolfe, the discovery and the development of original palladium-based catalysts for C(sp2 )-N bond formation via the coupling of nitrogen nucleophiles and aryl/alkenyl halides and pseudohalides. The authors also report various applications of these transformations to the synthesis of useful compounds, including biologically active molecules and materials.

214p coduathanh1122 27-03-2024 7 1   Download

Ebook "Development of novel hydrogen-bond donor catalysts" describes novel, effective hydrogen-bond (HB) donor catalysts based on a known bifunctional tertiary amine-thiourea, a privileged structure, which has been proven to be one of the most widely used organocatalysts. These HB donor catalysts derived from quinazoline and benzothiadiazine were initially synthesized as novel HB donors with their HB-donating abilities being measured by analytical methods.

119p coduathanh1122 27-03-2024 1 1   Download

Ebook "Chemical transformations of vinylidenecyclopropanes" review their investigations on the chemistry of VDCPs, mainly including the preparation, the reactivities upon treatment with Lewis or Brønsted acid, as well as transition metal catalysts and some other miscellaneous analogues. The contributions aroused a renaissance of cationic intermediates in the chemistry of VDCPs.

73p coduathanh1122 27-03-2024 2 1   Download

Ebook "Characterization and design of zeolite catalysts: Solid acidity, shape selectivity and loading properties" provide us the strong acidity with the fine distribution which enables various useful catalytic reactions. When some metals and cations are loaded in close to the acid sites, these loaded elements show extraordinary characters, and many catalytic reactions proceed thereon. Microporosity provides us a unique property of the shape selectivity, and the excellent selectivity is observed.

189p manmanthanhla0201 26-02-2024 1 1   Download

Ebook "Handbook of Industrial catalysts" has been written about fundamental aspects of catalysis, yet despite their universal applications details concerning commercial catalysts and information about actual operating conditions are not readily available. This book provides up-to-date reviews and references to guide those working on industrial catalysts. It will be an invaluable guide for catalysis researchers in industry and academia, and for students.

506p manmanthanhla0201 26-02-2024 4 1   Download

Using amino acids for synthesis of heterocycles is a synthetically promising field. However, developing the practical methods for transformations of amino acids into heterocycles is still challenging. Given that alpha amino acids are abundant or easily prepared, herein we report a method for annulation of benzylic C-H bonds in derivatives of 2-phenylglycine with 1-(2-nitroaryl) pyrroles.

3p vimichaelfaraday 28-12-2023 8 3   Download

The discharge of 4-nitrophenol (4-NP) into natural water has prompted scientific efforts for remediation. Many effective catalysts have been proposed to reduce 4-NP using sodium borohydride, highlighting factors like robust Lewis acidity, π-conjugate systems, and water stability to enhance 4- NP decomposition.

12p vimichaelfaraday 28-12-2023 6 4   Download

Part 1 book "Marks' basic medical biochemistry - A clinical approach" includes content: Metabolic fuels and dietary components; the fed or absorptive state; water, acids, bases, and buffersm; structures of the major compounds of the body; amino acids in proteins; structure function relationships in proteins; enzymes as catalysts; regulation of enzymes; relationship between cell biology and biochemistry; cell signaling by chemical messengers.

382p oursky07 24-10-2023 8 2   Download

The influence of the calcination mode of solegel synthesis on the crystallization properties of ferric pseudobrookite Fe2TiO5 (FTO) was investigated. The characteristics of pseudobrookite were identified by various methods: TGA, XRD, FT-IR, BET adsorption, EDX, EDS mapping, Raman spectroscopy, UV-Vis, SEM, and TEM.

10p viberbers 09-08-2023 3 3   Download

Mesoporous TiO2 mixed with NiTiO3 at various concentrations was synthesized by combining solegel and eco-friendly hydrothermal methods. The properties of the NiTiO3eTiO2 (NTOeTi) photocatalyst were characterized using Х-ray diffraction, Raman spectroscopy, scanning electron microscopy, Fouriertransform infrared spectroscopy, BrunauereEmmetteTeller adsorption, energy dispersive X-ray, and UV evis absorption spectra techniques.

8p viberbers 09-08-2023 7 3   Download

As an atom economy technology, the direct esterification reaction of olefins plays a significant role in the production of organic esters. In this work, a series of resin-supported HPW catalysts were prepared using D101, D152, RM027, and A15 as the carriers, and they were used to prepare 1-methylpentyl acetate by the esterification of 1-hexene and acetic acid.

10p viberbers 09-08-2023 12 3   Download

In this study we synthesized submicron silica powder from rice husk as an low-cost and renewable source and then incorporate metallic Cu onto it by using wet chemical reactions. The obtained material can be used in the future as potential catalyst for many organic reactions.

5p vidoctorstrange 06-05-2023 3 2   Download

We performed a theoretical study, at the BLYP/aug-cc-pVDZ theoretical level, of the mechanisms of H-transfer between biologically relevant tautomers of cytosine and guanine. The analysis of the ground- and excited state energy barriers of the conversions showed that in some cases they are lower as compared to the ground state reactions. The inclusion of one water molecule as a catalyst in the oxo-amino form of cytosine and guanine drastically changes the mechanism of the reactions in the ground as well as in the excited state.

9p lyhuyenthu 31-01-2023 6 2   Download

In this study, ternary mixed oxide catalysts containing Al2O3-MoO3-MgO and Al2O3-MoO3-WO3 were prepared with a changing ratio of MoO3:Al2O3 between 0.05 and 20.00. All catalysts showed 100% selectivity towards propene during the conversion of propan-2-ol at temperatures between 220 and 400 °C. The catalysts prepared from WO3 possessed very strong acid sites, which cause higher catalytic activity than catalysts prepared from MgO.

12p lyhuyenthu 31-01-2023 4 2   Download

Guar (GG) and locust bean (LBG) galactomannans (GMs) oxidation at C-6 was performed with catalyst TEMPO, in which the reaction progress was monitored by consume of NaOH solution. The products were characterized by spectroscopic analysis, infrared, and H-nuclear magnetic resonance, confirming the presence of aldehydes groups as intermediate of reaction to carboxylic acid.

8p vihermione 06-01-2023 3 2   Download