Catalytic synthesis of sulfur and phosphorus compounds via atom-economic reactions

2020 ◽  
Vol 30 (2) ◽  
pp. 129-138
Author(s):  
Shin-ichi Kawaguchi ◽  
Yuki Yamamoto ◽  
Akiya Ogawa
Keyword(s):  
Catalytic Synthesis ◽  
Phosphorus Compounds

On the reactivity of acetylenes coordinated to cobalt IV. The influence of tertiary phosphorus compounds on the catalytic synthesis of bifurandiones

1980 ◽  
Vol 9 (4) ◽  
pp. 457-460 ◽  
Author(s):  
Gyula Váradi ◽  
István T. Horváth ◽  
József Palágyi ◽  
Tibor Bak ◽  
Gyula Pályi
Keyword(s):  
Catalytic Synthesis ◽  
Phosphorus Compounds

Catalytic Synthesis of Cyclic Guanidines via Hydrogen Atom Transfer and Radical-Polar Crossover

2020 ◽  
Author(s):  
Shunya Ohuchi ◽  
Hiroki Koyama ◽  
Hiroki Shigehisa
Keyword(s):  
Hydrogen Atom ◽  
Functional Group ◽  
Hydrogen Atom Transfer ◽  
Catalytic Synthesis ◽  
Membered Ring ◽  
Biologically Active ◽  
Atom Transfer ◽  
Powerful Method ◽  
Protective Groups ◽  
The Common

A catalytic synthesis of cyclic guanidines, which are found in many biologically active compounds and natu-ral products, was developed, wherein transition-metal hydrogen atom transfer and radical-polar crossover were employed. This mild and functional-group tolerant process enabled the cyclization of alkenyl guanidines bearing common protective groups, such as Cbz and Boc. This powerful method not only provided the common 5- and 6-membered rings but also an unusual 7-membered ring. The derivatization of the products afforded various heterocycles. We also investigated the se-lective cyclization of mono-protected or hetero-protected (TFA and Boc) alkenyl guanidines and their further derivatiza-tions.

Solid, slightly soluble phosphorus compounds as nutrient source in activated sludge treatment of forest industry wastewaters

1997 ◽  
Vol 35 (2-3) ◽  
pp. 131-138 ◽  
Author(s):  
Pirjo-Riitta Rantala ◽  
Hannu Wirola
Keyword(s):  
Activated Sludge ◽  
The Other ◽  
Phosphorus Compounds ◽  
Forest Industry ◽  
Phosphorus Concentration ◽  
Nutrient Source ◽  
Sludge Treatment ◽  
Grain Sizes ◽  
Soluble Phosphorus ◽  
The Mean

The aim of the study was to determine if solid, slightly soluble compounds can be used as nutrient source in activated sludge treatment plants instead of liquid phosphoric acid. Four different solid materials were tested in lab-scale solubility tests to find compounds which are least soluble. Two materials were chosen for further studies: apatite and raw phosphate. The use of apatite and raw phosphate as nutrient source was studied in lab-scale activated sludge reactors along with a control reactor where phosphorus was added in liquid form. The phosphorus dosage, measured as elementary phosphorus, was the same for all three reactors. The reactors were fed with pre-clarified chemi-thermomechanical pulp mill (CTMP) wastewater. There were no significant differences in the reductions of organic matter between the three reactors. The mean effluent concentration of total phosphorus was 3 mg P/l in the control reactor and less than 1 mg P/1 in the other two reactors. The soluble phosphorus concentration was more than 2 mg P/l in the control reactor and less than 0.5 mg P/l in the other two. Apatite was an even better nutrient source than raw phosphate. Further lab-scale tests were conducted using two different grain sizes of apatite. No significant differences were found between the studied grain sizes (<0.074 mm and 0.074 mm-0.125 mm). Apatite was then used in full-scale at a CTMP-mill two different times. The experiments showed that the mean concentrations of phosphorus can be reduced radically by using apatite as a nutrient source instead of liquid phosphorus. Solid phosphorus compounds are a viable alternative to reduce the phosphorus load from forest industry wastewater treatment plants.

Synthesis of 3,4-Dihydropyrimidin-2(1H)-one Derivatives Using Activated Montmorillonite as Catalyst

2018 ◽  
Vol 16 (1) ◽  
pp. 59-65
Author(s):  
Sofiane Mekki ◽  
Lahcen Krabia ◽  
Saleh Mahmoud Saleh Mohamed ◽  
Salima Saidi-Besbes
Keyword(s):  
Catalytic Synthesis ◽  
Montmorillonite Clays

An efficient catalytic synthesis of 4-aryl-3,4-dihydropyrimidine-2(1H)-one derivatives using copper (II), iron (III) and zinc (II) exchanged montmorillonite clays as a catalyst is described. The desired products were obtained in good yields.

Catalytic Synthesis of Bulk Hydrophilic Acetaldehyde-Modified Polyamide 46

2014 ◽  
Vol 11 (2) ◽  
pp. 288-294
Author(s):  
Hamidreza Barghi ◽  
Mikael Skrifvars ◽  
Mohammad Taherzadeh
Keyword(s):  
Catalytic Synthesis
Sign in / Sign up

Export Citation Format

Share Document