The Mechanism of Dimethyl Sulfoxide Catalysis in Nucleophilic Displacement

1964 ◽  
Vol 29 (11) ◽  
pp. 3262-3270 ◽  
Author(s):  
Charles A. Kingsbury
Keyword(s):  
Dimethyl Sulfoxide ◽  
Nucleophilic Displacement

Mechanisms of Nucleophilic Displacement in Aqueous Dimethyl Sulfoxide Solutions

1961 ◽  
Vol 83 (20) ◽  
pp. 4281-4284 ◽  
Author(s):  
Richard Fuchs ◽  
Gloria E. McCrary ◽  
Jordan J. Bloomfield
Keyword(s):  
Dimethyl Sulfoxide ◽  
Nucleophilic Displacement

Solvation enthalpies and rates of nucleophilic displacement of alkali halides in dimethyl sulfoxide

1968 ◽  
Vol 90 (24) ◽  
pp. 6698-6700 ◽  
Author(s):  
R. F. Rodewald ◽  
K. Mahendran ◽  
John L. Bear ◽  
Richard. Fuchs
Keyword(s):  
Dimethyl Sulfoxide ◽  
Alkali Halides ◽  
Nucleophilic Displacement

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

Preservation of Morphological Integrity and Clot Retraction Activity of Human Platelets After Freezing

1964 ◽  
Vol 11 (01) ◽  
pp. 222-229 ◽  
Author(s):  
Isaac Djerassi ◽  
Albert Roy ◽  
Jorge Alvarado ◽  
Keyword(s):  
Dimethyl Sulfoxide ◽  
Liquid Nitrogen ◽  
Human Platelets ◽  
Slow Freezing ◽  
Critical Conditions ◽  
Plasma Medium ◽  
Clot Retraction ◽  
Controlled Freezing ◽  
Direct Immersion

SummaryHuman platelets frozen at −195° C (liquid nitrogen) retain their morphological integrity and ability to promote clot retraction when 5% dimethyl-sulfoxide and 5% dextrose are added to the suspending plasma medium. Slow freezing was more effective than direct immersion in the liquid nitrogen. Although similar results may be achieved with dimethylsulfoxide alone with rigidly controlled freezing rates, the addition of sugars may permit freezing under less critical conditions.Dimethylsulfoxyd und 5% Dextrose dem Plasmamilieu hinzugefügt werden. Das langsame Einfrieren ist effektiver als das direkte Eintauchen in flüssigen Stickstoff. Obschon ähnliche Resultate mit Dimethylsulfoxyd allein unter exakter Kontrolle der Einfrierungsgeschwindig-keit erreicht werden können, erlaubt die Zugabe von Dextrose ein Einfrieren unter weniger kritischen Bedingungen.

Bifluoride Ion Mediated SuFEx Trifluoromethylation of Sulfonyl Fluorides and Iminosulfur Oxydifluorides

2018 ◽  
Author(s):  
Christopher J. Smedley ◽  
Bing Gao ◽  
Suhua Li ◽  
Qinheng Zheng ◽  
Andrew Molino ◽  
...  
Keyword(s):  
Breast Cancer Cells ◽  
Catalytic Mechanism ◽  
Bioactive Molecules ◽  
Chromatographic Purification ◽  
Rapid Exchange ◽  
Nucleophilic Displacement ◽  
Sulfur Fluoride ◽  
Reactions With Nucleophiles ◽  
New Generation ◽  
Selection Of

Sulfur-Fluoride Exchange (SuFEx) is the new generation click chemistry transformation exploiting the unique properties of S-F bonds and their ability to undergo near-perfect reactions with nucleophiles. We report here the first SuFEx based protocol for the efficient synthesis of pharmaceutically important triflones and bis(trifluoromethyl)sulfur oxyimines from the corresponding sulfonyl fluorides and iminosulfur oxydifluorides, respectively. The new protocol involves the rapid exchange of the S-F bond with trifluoromethyltrimethylsilane (TMSCF<sub>3</sub>) upon activation with potassium bifluoride in anhydrous DMSO. The reaction tolerates a wide selection of substrates and proceeds under mild conditions without need for chromatographic purification. A tentative catalytic mechanism is proposed supported by DFT calculations, involving formation of the free trifluoromethyl anion followed by nucleophilic displacement of the S-F through a five-coordinate intermediate. The preparation of a benzothiazole derived bis(trifluoromethyl)sulfur oxyimine with cytotoxic selectivity for MCF7 breast cancer cells demonstrates the utility of this methodology for the late-stage functionalization of bioactive molecules.<br>

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