scholarly journals Tipping Point for Expansion of Layered Aluminosilicates in Weakly Polar Solvents: Supercritical CO2

2017 ◽  
Vol 9 (42) ◽  
pp. 36783-36791 ◽  
Author(s):  
Herbert T. Schaef ◽  
Narasimhan Loganathan ◽  
Geoffrey M. Bowers ◽  
R. James Kirkpatrick ◽  
A. Ozgur Yazaydin ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Tipping Point ◽  
Polar Solvents

A Study of the Heck Reaction in Non-Polar Hydrocarbon Solvents and in Supercritical Carbon Dioxide

2007 ◽  
Vol 60 (8) ◽  
pp. 566 ◽  
Author(s):  
Jin-Kyun Lee ◽  
Rachel M. Williamson ◽  
Andrew B. Holmes ◽  
Edward J. Bush ◽  
Ian F. McConvey
Keyword(s):  
Butyl Acrylate ◽  
Heck Reaction ◽  
Supercritical Co2 ◽  
Phosphine Ligands ◽  
Triphenyl Phosphite ◽  
Heck Reactions ◽  
Polar Solvents ◽  
Phosphorus Ligands ◽  
Hydrocarbon Solvents ◽  
Sterically Demanding

The effects of electronic and steric properties of phosphorus ligands on Heck reactions in supercritical CO2 and non-polar hydrocarbon solvents were studied. In Heck reactions between iodobenzene and butyl acrylate, higher yields were obtained with less electron-rich phosphine ligands. This trend was also observed with the electron-poor triphenyl phosphite. A range of sterically demanding phosphites were then investigated. Biphenyl-containing phosphites 8 and 13 were found to be highly effective. In the Heck reaction between the less-reactive bromobenzene and butyl acrylate, the bulky, electron-rich tri-tert-butylphosphine ligand produced the best yield. These results emphasize the importance of both electronic and steric properties of phosphorus ligands in the Heck reaction in non-polar solvents.

Spreading popularity of two musical artists: A "tipping point" study

2004 ◽  
Author(s):  
Alan Reifman ◽  
Laihan Lee ◽  
Malathi Apparala
Keyword(s):  
Tipping Point

Anti-diabetic properties of non-polar Toona sinensis Roem extract prepared by supercritical-CO2 fluid

Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
YH Tsai ◽  
TJ Hsieh ◽  
MC Liao ◽  
PJ Lien ◽  
CC Sun ◽  
...  
Keyword(s):  
Supercritical Co2 ◽  
Toona Sinensis ◽  
Supercritical Co2 Fluid

Tele-Substitution Reactions in the Synthesis of a Promising Class of Antimalarials

2020 ◽  
Author(s):  
Marat Korsik ◽  
Edwin Tse ◽  
David Smith ◽  
William Lewis ◽  
Peter J. Rutledge ◽  
...  
Keyword(s):  
Heterocyclic Ring ◽  
Ring System ◽  
Substitution Reactions ◽  
Laboratory Notebook ◽  
Polar Solvents ◽  
X Ray ◽  
X Ray Crystallography ◽  
The Core ◽  
Nmr Data

<p></p><p>We have discovered and studied a <i>tele</i>substitution reaction in a biologically important heterocyclic ring system. Conditions that favour the <i>tele</i>-substitution pathway were identified: the use of increased equivalents of the nucleophile or decreased equivalents of base, or the use of softer nucleophiles, less polar solvents and larger halogens on the electrophile. Using results from X-ray crystallography and isotope labelling experiments a mechanism for this unusual transformation is proposed. We focused on this triazolopyrazine as it is the core structure of the <i>in vivo </i>active anti-plasmodium compounds of Series 4 of the Open Source Malaria consortium.</p> <p> </p> <p>Archive of the electronic laboratory notebook with the description of all conducted experiments and raw NMR data could be accessed via following link <a href="https://ses.library.usyd.edu.au/handle/2123/21890">https://ses.library.usyd.edu.au/handle/2123/21890</a> . For navigation between entries of laboratory notebook please use file "Strings for compounds in the article.pdf" that works as a reference between article codes and notebook codes, also this file contain SMILES for these compounds. </p><br><p></p>

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