σ-Complexes as biophysical and biochemical probes. Part II. Transformations of σ-complex intermediates from reaction of 4-nitrobenzofuroxan and methoxide ion

1977 ◽  
Vol 55 (15) ◽  
pp. 2852-2855 ◽  
Author(s):  
Erwin Buncel ◽  
Noemi Chuaqui-Offermanns ◽  
Brian K. Hunter ◽  
Albert R. Norris
Keyword(s):  
Reaction Mechanism ◽  
Dimethyl Sulphoxide ◽  
Antileukemic Activity ◽  
Methoxide Ion ◽  
Transient Intermediates

Reaction of 4-nitrobenzofuroxan with methoxide ion in methanolic dimethyl sulphoxide solution gives rise to 7-hydroxy-4-nitrobenzofurazan (as the anion) and 7-methoxy-4-nitrobenzofurazan (as the methoxide C-7 adduct); the proposed reaction mechanism invokes the formation of several transient intermediates. The results bear on the postulated mechanism for the antileukemic activity of 4-nitrobenzofuroxan.

Interaction of heterocycles and nucleophiles. II. Sigma complexes formed from methoxide ion and Methoxy-3,5-dinitropyridines in dimethyl sulphoxide

1970 ◽  
Vol 23 (5) ◽  
pp. 957 ◽  
Author(s):  
MEC Biffin ◽  
J Miller ◽  
AG Moritz ◽  
DB Paul
Keyword(s):  
Dimethyl Sulphoxide ◽  
No Conversion ◽  
Solvation Effects ◽  
Sigma Complexes ◽  
Sigma Complex ◽  
Methoxide Ion ◽  
Rearrangement Reactions

Contrasting behaviour is observed when 2- and 4-methoxy-3,5-dinitropyridine interact with methoxide ion in dimethyl sulphoxide. The 4-methoxy compound affords both methine and acetal sigma complexes, the latter being thermodynamically more stable. The interconversion is catalysed by methanol. Labelling experiments have established that the sigma complex from the 2-methoxypyridine is formed by addition at C6; no conversion into the acetal could be effected. These observations are rationalized in terms of differential steric and solvation effects. Demethylation and rearrangement reactions of 4-methoxy-3,5-dinitropyridine are reported.

scholarly journals Interaction of heterocycles and nucleophiles. III. Interconversion of the methine sigma complexes derived from 3,5-dinitropyridine and methoxide ion in dimethyl sulphoxide

1970 ◽  
Vol 23 (5) ◽  
pp. 963 ◽  
Author(s):  
MEC Biffin ◽  
J Miller ◽  
AG Moritz ◽  
DB Paul
Keyword(s):  
Dimethyl Sulphoxide ◽  
Stable Isomer ◽  
Sigma Complexes ◽  
Methoxide Ion

The conversion of the methine complex (4; R1 = H) into the more stable isomer (5; R1 = R2 = H) is reported.

scholarly journals The Influence of the Solvent on Reaction Velocity. XXXI. The Reaction between Benzyl Chlorides and Methoxide Ion in Dimethyl Sulphoxide-Methanol Mixtures.

1966 ◽  
Vol 20 ◽  
pp. 946-962 ◽  
Author(s):  
Eero Tommila ◽  
Matti Savolainen ◽  
Inkeri Lehtinen ◽  
Bengt von Hofsten ◽  
D. H. Williams ◽  
...  
Keyword(s):  
Dimethyl Sulphoxide ◽  
Reaction Velocity ◽  
Benzyl Chlorides ◽  
Methoxide Ion

Arylation of enelactams using TIPSOTf: reaction scope and mechanistic insight

2021 ◽  
Author(s):  
Tomasz J. Idzik ◽  
Zofia M. Myk ◽  
Łukasz Struk ◽  
Magdalena Perużyńska ◽  
Gabriela Maciejewska ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Multinuclear Nmr ◽  
Mechanistic Insight ◽  
Nmr Study ◽  
Wide Range

Triisopropylsilyltrifluoromethanesulfonate can be effectively used for the arylation of a wide range of enelactams. The multinuclear NMR study provided deep insights into the reaction mechanism.

Theoretical study of the ketonization reaction mechanism of acetic acid over SiO2

2009 ◽  
Author(s):  
Mendel Fleisher ◽  
E. Lukevics ◽  
L. Leite ◽  
D. Jansone ◽  
K. Edolfa ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Theoretical Study
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