Role of Third Phase in Intensification of Reaction Rates and Selectivity:  Phase-Transfer Catalyzed Synthesis of Benzyl Phenyl Ether

2007 ◽  
Vol 46 (25) ◽  
pp. 8448-8458 ◽  
Author(s):  
Ganapati D. Yadav ◽  
Omprakash V. Badure
Keyword(s):  
Phase Transfer ◽  
Reaction Rates ◽  
Phenyl Ether ◽  
Third Phase ◽  
Benzyl Phenyl Ether

Organic Synthesis Engineering

2001 ◽  
Author(s):  
L. K. Doraiswamy
Keyword(s):  
Organic Synthesis ◽  
Phase Transfer ◽  
Heterogeneous Systems ◽  
Process Intensification ◽  
Reaction Rates ◽  
Main Theme ◽  
Scale Production ◽  
Phase Transfer Catalysts ◽  
Industrial Scale Production

This book will formally launch "organic synthesis engineering" as a distinctive field in the armory of the reaction engineer. Its main theme revolves around two developments: catalysis and the role of process intensification in enhancing overall productivity. Each of these two subjects are becoming increasingly useful in organic synthesis engineering, especially in the production of medium and small volume chemicals and enhancing reaction rates by extending laboratory techniques, such as ultrasound, phase transfer catalysts, membrane reactor, and microwaves, to industrial scale production. This volume describes the applications of catalysis in organic synthesis and outlines different techniques of reaction rate and/or selectivity enhancement against a background of reaction engineering principles for both homogeneous and heterogeneous systems.

Kinetics of Phase Transfer Catalytic Preparation of Benzyl Phenyl Ether

1985 ◽  
Vol 32 (2) ◽  
pp. 143-150 ◽  
Author(s):  
Mou-Yung Yeh ◽  
Tzong-Bin Lin ◽  
Yen-Ping Shih
Keyword(s):  
Phase Transfer ◽  
Phenyl Ether ◽  
Benzyl Phenyl Ether ◽  
Kinetics Of

The Role of Phase Transfer Catalysis in the Microwave-Assisted N-Benzylation of Amides, Imides and N-Heterocycles

2009 ◽  
Vol 6 (7) ◽  
pp. 529-534 ◽  
Author(s):  
Istvan Greiner ◽  
Fanni Sypaseuth ◽  
Alajos Grun ◽  
Eva Karsai ◽  
Gyorgy Keglevich
Keyword(s):  
Phase Transfer Catalysis ◽  
Phase Transfer ◽  
Microwave Assisted

ChemInform Abstract: PHOTOLYSIS OF BENZYL PHENYL ETHER

1978 ◽  
Vol 9 (14) ◽  
Author(s):  
H.-J. TIMPE ◽  
H.-J. FRIEDRICH ◽  
R. DIETRICH ◽  
J. BOECKELMANN ◽  
I. FRIEDEL
Keyword(s):  
Phenyl Ether ◽  
Benzyl Phenyl Ether

Third-phase catalytic activity of halogen exchange reactions in phase transfer catalytic system

1997 ◽  
Vol 52 (20) ◽  
pp. 3511-3520 ◽  
Author(s):  
Tadaatsu Ido ◽  
Takanobu Yamamoto ◽  
Gong Jin ◽  
Shigeo Goto
Keyword(s):  
Catalytic Activity ◽  
Catalytic System ◽  
Phase Transfer ◽  
Exchange Reactions ◽  
Third Phase ◽  
Halogen Exchange

scholarly journals Rare microbes from diverse Earth biomes dominate community activity

2019 ◽  
Author(s):  
Rohan Sachdeva ◽  
Barbara J. Campbell ◽  
John F. Heidelberg
Keyword(s):  
Community Structure ◽  
Microbial Activity ◽  
Ecosystem Function ◽  
Total Activity ◽  
Reaction Rates ◽  
Community Activity ◽  
Crucial Component ◽  
Tightly Coupled ◽  
The Relationship

AbstractMicrobes are the Earth’s most numerous organisms and are instrumental in driving major global biological and chemical processes. Microbial activity is a crucial component of all ecosystems, as microbes have the potential to control any major biochemical process. In recent years, considerable strides have been made in describing the community structure,i.e. diversity and abundance, of microbes from the Earth’s major biomes. In virtually all environments studied, a few highly abundant taxa dominate the structure of microbial communities. Still, microbial diversity is high and is concentrated in the less abundant, or rare, fractions of the community,i.e. the “long tail” of the abundance distribution. The relationship between microbial community structure and activity, specifically the role of rare microbes, and its connection to ecosystem function, is not fully understood. We analyzed 12.3 million metagenomic and metatranscriptomic sequence assemblies and their genes from environmental, human, and engineered microbiomes, and show that microbial activity is dominated by rare microbes (96% of total activity) across all measured biomes. Further, rare microbial activity was comprised of traits that are fundamental to ecosystem and organismal health,e.g. biogeochemical cycling and infectious disease. The activity of rare microbes was also tightly coupled to temperature, revealing a link between basic biological processes,e.g. reaction rates, and community activity. Our study provides a broadly applicable and predictable paradigm that implicates rare microbes as the main microbial drivers of ecosystem function and organismal health.

scholarly journals Numerical analysis of the chemical kinetic mechanisms of ozone depletion and halogen release in the polar troposphere

2013 ◽  
Vol 13 (9) ◽  
pp. 24171-24222 ◽  
Author(s):  
L. Cao ◽  
H. Sihler ◽  
U. Platt ◽  
E. Gutheil
Keyword(s):  
Boundary Layer ◽  
Surface Area ◽  
Ozone Depletion ◽  
Reaction Rates ◽  
The Arctic ◽  
Strong Impact ◽  
Reactive Surface ◽  
A Value ◽  
Halogen Species

Abstract. In recent years, the role of halogen species (e.g. Br, Cl) in the troposphere of polar regions is investigated after the discovery of their importance for boundary layer ozone destruction in the polar spring. Halogen species take part in an auto-catalytic chemical cycle including key self reactions. In this study, several chemical reaction schemes are investigated, and the importance of specific reactions and their rate constants is identified by a sensitivity analysis. A category of heterogeneous reactions related to HOBr activate halogen ions from sea salt aerosols, fresh sea ice or snow pack, driving the "bromine explosion". In the Arctic, a small amount of NOx may exist, which comes from nitrate contained in the snow, and this NOx may have a strong impact on ozone depletion. The heterogeneous reaction rates are parameterized by considering the aerodynamic resistance, a reactive surface ratio, β, i.e. ratio of reactive surface area to total ground surface area, and the boundary layer height, Lmix. It is found that for β = 1, the ozone depletion process starts after five days and lasts for 40 h for Lmix = 200 m. Ozone depletion duration becomes independent of the height of the boundary layer for about β≥20, and it approaches a value of two days for β=100. The role of nitrogen and chlorine containing species on the ozone depletion rate is studied. The calculation of the time integrated bromine and chlorine atom concentrations suggests a value in the order of 103 for the [Br] / [Cl] ratio, which reveals that atomic chlorine radicals have minor direct influence on the ozone depletion. The NOx concentrations are influenced by different chemical cycles over different time periods. During ozone depletion, the reaction cycle involving the BrONO2 hydrolysis is dominant. A critical value of 0.002 of the uptake coefficient of the BrONO2 hydrolysis reaction at the aerosol and saline surfaces is identified, beyond which the existence of NOx species accelerate the ozone depletion event – for lower values, deceleration occurs.

Phase-Transfer-Catalyzed Intramolecular Cyclization ofortho-Alkynyl Phenyl Ether Derivatives for Synthesis of 2,3-Disubstituted Benzo[b]furans

2010 ◽  
Vol 352 (2-3) ◽  
pp. 351-356 ◽  
Author(s):  
Jie Hu ◽  
Lu-Yong Wu ◽  
Xiang-Chuan Wang ◽  
Yuan-Yuan Hu ◽  
Yan-Ning Niu ◽  
...  
Keyword(s):  
Intramolecular Cyclization ◽  
Phase Transfer ◽  
Phenyl Ether
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