An Acid Catalysed Intramolecular C–C Coupling Reaction of 8-halomethyl-16-methoxy[2.2]Metacyclophanes

2005 ◽  
Vol 2005 (8) ◽  
pp. 495-497 ◽  
Author(s):  
Kan Tanaka ◽  
Akira Miyazawa ◽  
Ai Hiate ◽  
Masashi Tashiro ◽  
Tatsunori Saisyo ◽  
...  
Keyword(s):  
Sulfonic Acid ◽  
Methoxy Group ◽  
Coupling Reaction ◽  
Aqueous Dioxane ◽  
Dioxane Solution ◽  
Coupling Product ◽  
Hydrolysis Of

The hydrolysis of 8-bromomethyl[2.2]metacyclophane 1a with a methoxy group at the 16-position was carried out in an 80% aqueous dioxane solution by refluxing in the presence of Nafion-H (a solid perfluorinated resin sulfonic acid) as a catalyst. The reaction yielded the corresponding 8-hydroxymethyl[2.2]metacyclophane 3 and the intramolecular C–C coupling product 2 with a spiro skeleton.

scholarly journals Pretreatment of Switchgrass for Production of Glucose via Sulfonic Acid-Impregnated Activated Carbon

Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 504
Author(s):  
Yane Ansanay ◽  
Praveen Kolar ◽  
Ratna Sharma-Shivappa ◽  
Jay Cheng ◽  
Consuelo Arellano
Keyword(s):  
Activated Carbon ◽  
Sulfonic Acid ◽  
Solid Acid ◽  
Methanesulfonic Acid ◽  
Biofuel Production ◽  
Acid Catalysts ◽  
Effects Of Temperature ◽  
Carbon Catalysts ◽  
Hydrolysis Of

In the present research, activated carbon-supported sulfonic acid catalysts were synthesized and tested as pretreatment agents for the conversion of switchgrass into glucose. The catalysts were synthesized by reacting sulfuric acid, methanesulfonic acid, and p-toluenesulfonic acid with activated carbon. The characterization of catalysts suggested an increase in surface acidities, while surface area and pore volumes decreased because of sulfonation. Batch experiments were performed in 125 mL serum bottles to investigate the effects of temperature (30, 60, and 90 °C), reaction time (90 and 120 min) on the yields of glucose. Enzymatic hydrolysis of pretreated switchgrass using Ctec2 yielded up to 57.13% glucose. Durability tests indicated that sulfonic solid-impregnated carbon catalysts were able to maintain activity even after three cycles. From the results obtained, the solid acid catalysts appear to serve as effective pretreatment agents and can potentially reduce the use of conventional liquid acids and bases in biomass-into-biofuel production.

scholarly journals Microwaves as “Co-Catalysts” or as Substitute for Catalysts in Organophosphorus Chemistry

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1196
Author(s):  
György Keglevich
Keyword(s):  
Coupling Reaction ◽  
Diels Alder ◽  
Typical Case ◽  
Conventional Heating ◽  
Phosphine Oxides ◽  
Phosphonic Acids ◽  
Co Catalysts ◽  
Mw Irradiation ◽  
Organophosphorus Chemistry ◽  
Hydrolysis Of

The purpose of this review is to summarize the importance of microwave (MW) irradiation as a kind of catalyst in organophosphorus chemistry. Slow or reluctant reactions, such as the Diels-Alder cycloaddition or an inverse-Wittig type reaction, may be performed efficiently under MW irradiation. The direct esterification of phosphinic and phosphonic acids, which is practically impossible on conventional heating, may be realized under MW conditions. Ionic liquid additives may promote further esterifications. The opposite reaction, the hydrolysis of P-esters, has also relevance among the MW-assisted transformations. A typical case is when the catalysts are substituted by MWs, which is exemplified by the reduction of phosphine oxides, and by the Kabachnik–Fields condensation affording α-aminophosphonic derivatives. Finally, the Hirao P–C coupling reaction may serve as an example, when the catalyst may be simplified under MW conditions. All of the examples discussed fulfill the expectations of green chemistry.

Copper(II) Chloride Catalyzed Carboxydediazoniation of Arenediazonium Tetrafluoroborates with Carbon Monoxide in Aqueous Dioxane Solution to Arenecarboxylic Acids1

Synlett ◽  
1990 ◽  
Vol 1990 (10) ◽  
pp. 596-598 ◽  
Author(s):  
George A. Olah ◽  
An-hsiang Wu ◽  
Alessandro Bagno ◽  
G. K. Surya Prakash
Keyword(s):  
Carbon Monoxide ◽  
Aqueous Dioxane ◽  
Dioxane Solution

Acid–base synergistic catalysis of biochar sulfonic acid bearing polyamide for microwave-assisted hydrolysis of cellulose in water

Cellulose ◽  
2018 ◽  
Vol 26 (2) ◽  
pp. 751-762 ◽  
Author(s):  
Zengtian Chen ◽  
Qingfeng Li ◽  
Yuxue Xiao ◽  
Chao Zhang ◽  
Zaihui Fu ◽  
...  
Keyword(s):  
Sulfonic Acid ◽  
Acid Base ◽  
Synergistic Catalysis ◽  
Microwave Assisted ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

scholarly journals Novel Greener Microwave-Assisted Deprotection Methodology for the 1,3-Dioxolane Ketal of Isatin Using Calix[n]arenes

2022 ◽  
Author(s):  
Lucas Barbosa ◽  
Tiago da Silva ◽  
Michelle Rezende ◽  
Bianca da Silva ◽  
Rodrigo Guzzo ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Sulfonic Acid ◽  
Microwave Energy ◽  
Protecting Group ◽  
Additional Advantage ◽  
Microwave Assisted ◽  
Combined Use ◽  
Ketone Carbonyl ◽  
First Time ◽  
Hydrolysis Of

In this work, the combined use of p-sulfonic acid-calix[n]arene and microwave energy to hydrolyze the 1,3-dioxolane ketal of isatin was evaluated with excellent results. This is the first time that p-sulfonic acid-calix[n]arene has been used as the catalyst in a ketal hydrolysis reaction and the deprotection of the ketone carbonyl of isatin is reported. The presence of 2.5 mol% of p-sulfonic acid-calix[4,6]arene at 160 ºC resulted in over 96% conversion of this ketal in 10 min, with the additional advantage of using water as a solvent. This catalytic system (aqueous phase containing p-sulfonic acid-calix[4]arene) was reused for five consecutive cycles, with a conversion above 96% maintained. This reusable system is not practicable using p-toluenesulfonic acid and p-hydroxybenzenesulfonic acid as catalysts since both are extracted to the organic phase with the reaction product. The hydrolysis of 1,3-dioxolane ketal of isatins with different substituents (CH3, I, Br, Cl, F, NO2) in the aromatic ring was also evaluated. The protecting group of 5-methyl-isatin was removed with 73% conversion using 2.5 mol% of p-sulfonic acid-calix[4]arene at 160 ºC for 5 min. In contrast, the ketal of 5-nitro-isatin reached 80% conversion using the same conditions after 40 min.

scholarly journals Crystal structure of 1,4-bis[5-(2-methoxyphenyl)-2H-tetrazol-2-yl]butane

2019 ◽  
Vol 75 (12) ◽  
pp. 1844-1847
Author(s):  
Young Min Byun ◽  
Farwa Ume ◽  
Ji Yeon Ryu ◽  
Junseong Lee ◽  
Hyoung-Ryun Park
Keyword(s):  
Title Compound ◽  
Methoxy Group ◽  
Coupling Reaction ◽  
Major Product ◽  
Molar Ratio ◽  
Dihedral Angles ◽  
X Ray ◽  
Compound C ◽  
Crystallographic Study ◽  
Centrosymmetric Dimers

The title compound, C20H22N8O2, was synthesized by the coupling reaction of a sodium tetrazolate salt and dibromobutane in a molar ratio of 2:1. The reaction can produce several possible regioisomers and the title compound was separated as the major product. The X-ray crystallographic study confirmed that the title compound crystallizes in the monoclinic P21/c space group and possesses a bridging butylene group that connects two identical phenyl tetrazole moieties. The butylene group is attached not to the first but the second nitrogen atoms of both tetrazole rings. The dihedral angles between the phenyl groups and the adjacent tetrazolyl rings are 5.32 (6) and 15.37 (7)°. In the crystal, the molecules form centrosymmetric dimers through C—H...O hydrogen bonds between a C—H group of the butylene linker and the O atom of a methoxy group.

Hydrolysis of Sulfonic Acid Esters

2008 ◽  
pp. 1
Author(s):  
J. Drabowicz ◽  
P. Kiełbasiński ◽  
P. Łyżwa ◽  
A. Zając ◽  
M. Mikołajczyk
Keyword(s):  
Sulfonic Acid ◽  
Hydrolysis Of ◽  
Acid Esters
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