Microemulsion Mediated Organic Synthesis and the Possible Reaction Site

2016 ◽  
Vol 32 (1-2) ◽  
pp. 7 ◽  
Author(s):  
Prasanjit Ghosh ◽  
Barnali Kar ◽  
Soumik Bardhan ◽  
Kaushik Kundu ◽  
Swapan Kumar Saha ◽  
...  
Keyword(s):  
Organic Synthesis ◽  
Phase Transfer ◽  
Heterogeneous Systems ◽  
Short Review ◽  
Water Soluble ◽  
Organic Reactions ◽  
Polar Component ◽  
Water Interface ◽  
Oil Water ◽  
Reaction Media

Microemulsions (mEs), being thermodynamically stable, single phasic transparent mixtures of oil, water, surfactant ( either individually or in mixed state) and/or co-surfactant, are exemplary and multi dimensional reaction media in organic synthesis. They can act as an alternative of the phase transfer catalysis and influence the rate of the reaction due to the presence of charged carriers (amphiphiles) at the oil/water interface. The regioselectivity of many organic reactions can also be induced by employing mEs as templates. In particular, organic molecules with different degrees of polarity tend to accumulate at the oil/water interface of mEs. Subsequently, they orient themselves at the interface in such a way that the polar component extends into the water domain and the nonpolar component protrudes towards hydrocarbon domain. In view of this, a water-soluble reagent attacks the polar part of the amphiphile, and a reagent soluble in hydrocarbon reacts at the nonpolar part of the amphiphile. Because of this unique feature, use of mEs (or micro heterogeneous systems) as templates for studying organic reactions, have increased manifolds. In this short review, we mainly exemplify (i) mEs as reaction media, (ii) effect of microstructure of mEs on organic transformations and (iii) the most possible reaction location/site in mEs.

Microemulsions as microreactors in physical organic chemistry

2007 ◽  
Vol 79 (6) ◽  
pp. 1111-1123 ◽  
Author(s):  
Luis García-Río ◽  
J. Ramon Leis ◽  
Juan Carlos Mejuto ◽  
Moisés Pérez-Lorenzo
Keyword(s):  
Organic Chemistry ◽  
Organic Molecules ◽  
Reaction Rates ◽  
Organic Reactions ◽  
Water Interface ◽  
Physical Organic Chemistry ◽  
Organic Reaction ◽  
Physical Organic ◽  
Oil Water ◽  
Reaction Media

Microemulsions are very versatile reaction media which nowadays find many applications, ranging from nanoparticle templating to preparative organic chemistry. The thermodynamically stable and microheterogeneous nature of microemulsions, used as reaction media, induces drastic changes in the reagent concentrations, and this can be specifically used for tuning the reaction rates. In particular, amphiphilic organic molecules can accumulate and orient at the oil-water interface, inducing regiospecificity in organic reactions. In this review, we will show the recent tendencies of the use of microemulsions as organic reaction media.

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.

Room-Temperature-Cured Polydimethylsiloxane Elastomers from Aqueous Dispersion

1981 ◽  
Vol 54 (5) ◽  
pp. 976-987 ◽  
Author(s):  
J. C. Saam ◽  
D. Graiver ◽  
M. Baile
Keyword(s):  
Room Temperature ◽  
Colloidal Silica ◽  
Aqueous Dispersion ◽  
Water Soluble ◽  
Alkaline Media ◽  
Water Interface ◽  
Anionic Charge ◽  
Oil Water ◽  
Emulsion Particle

Abstract The observations are consistent with the formation of grafts of hydrophilic silicates to the silanol chain ends at the surface of the PDMS emulsion particles prior to removal of the water. The silicates may be introduced into the system directly or through the alkaline colloidal silica, which contains appreciable amounts of dissolved silicates. Monomeric, or possibly dimeric, silicate grafted to more than one chain end could migrate to the interior of the PDMS emulsion particle to form further crosslinks. Grafts to higher molecular weight silicates and silicate grafts bearing anionic charge would be solvated with water and tend to remain at the oil-water interface. This could provide steric as well as ionic stabilization to the PDMS particles, and the system would no longer respond to electrolytes as a simple, ionically stabilized, hydrophobic colloid but more as a hydrophilic colloid resembling silica. The role of the dioctyltin dilaurate is to interact in the water phase with the water-soluble silicates to render them, in effect, hydrophobic and to transport them to the oil-water interface. There the dialkyltin species can catalyze condensation between silanol on the silicate with silanol on the PDMS chain ends. Alkyltin acylates are known to hydrolyze in aqueous alkaline media, and the product can condense with silanol on the silicate to form silastannoxane intermediates. These are relatively stable to hydrolysis, provided bulky groups are present on tin as in dioctyltin dilaurate.

Competitive Adsorption of Water Soluble Plasma Proteins from Egg Yolk at the Oil/Water Interface

2006 ◽  
Vol 54 (18) ◽  
pp. 6881-6887 ◽  
Author(s):  
Lars Nilsson ◽  
Peter Osmark ◽  
Céline Fernandez ◽  
Marcus Andersson ◽  
Björn Bergenståhl
Keyword(s):  
Plasma Proteins ◽  
Competitive Adsorption ◽  
Egg Yolk ◽  
Water Soluble ◽  
Water Interface ◽  
Adsorption Of Water ◽  
Oil Water

Distribution of phase transfer biocatalyst at the oil/water interface by membrane emulsifier and evaluation of enantiocatalytic performance

Desalination ◽  
2006 ◽  
Vol 199 (1-3) ◽  
pp. 182-184
Author(s):  
Lidietta Giorno ◽  
Emma Piacentini ◽  
Rosalinda Mazzei ◽  
Enrico Drioli
Keyword(s):  
Phase Transfer ◽  
Water Interface ◽  
Oil Water

scholarly journals Nucleophilic Trifluoromethylation Reactions Involving Copper(I) Species: From Organometallic Insights to Scope

Synthesis ◽  
2019 ◽  
Vol 51 (14) ◽  
pp. 2809-2820 ◽  
Author(s):  
Ángel L. Mudarra ◽  
Sara Martínez de Salinas ◽  
Mónica H. Pérez-Temprano
Keyword(s):  
Organic Synthesis ◽  
Historical Perspective ◽  
Short Review ◽  
Copper Species ◽  
Bond Forming ◽  
Comprehensive Picture ◽  
Real Behavior ◽  
In Situ Generation ◽  
Reaction Media

Over the last decades, trifluoromethyl copper(I) complexes have played a key role as reactive species in C–CF3 bond-forming reactions. This Short Review not only covers selected examples of relevant copper-mediated or catalyzed nucleophilic trifluoromethylation reactions, which is one of the most active fields in organic synthesis, but also provides a comprehensive picture of the real behavior of these copper species, including ubiquitous cuprates, in the reaction media.1 Introduction2 Historical Perspective of the Identification of Relevant Trifluoro- methyl Copper(I) Species3 In Situ Generation of Active Trifluoromethyl Copper(I) Species 4 Well-Defined Active Trifluoromethyl Copper(I) Complexes5 Recent Advances on the Performance of Trifluoromethylation Protocols6 Conclusions

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