ChemInform Abstract: Facile Nucleophilic Cleavage of Selenide with Dimedone. Synthesis of Novel 6-Demethylmitomycins.

ChemInform ◽  
2010 ◽  
Vol 24 (46) ◽  
pp. no-no
Author(s):  
H. ARAI ◽  
M. KASAI
Keyword(s):  
Nucleophilic Cleavage

Nucleophilic cleavage of diaryl disulphides

1973 ◽  
Vol 26 (1) ◽  
pp. 121 ◽  
Author(s):  
DAR Happer ◽  
JW Mitchell ◽  
GJ Wright
Keyword(s):  
Transition State ◽  
Reaction Rate ◽  
Substituent Effects ◽  
Butyl Alcohol ◽  
Sulphur Atom ◽  
Cyanide Ion ◽  
Benzene Rings ◽  
Nucleophilic Cleavage ◽  
Rapid Equilibrium ◽  
Electron Withdrawal

The rates of cleavage of 14 symmetrically substituted diaryl disulphides by cyanide ion have been measured in 60% aqueous t-butyl alcohol at pH 9.2. A plot of log k against σ� shows that while the reaction rate is accelerated by inductive electron withdrawal from the benzene rings, substituents capable of conjugative interaction are not correlated by their σ� parameters. +R substituents cause reaction to occur much faster than predicted on the basis of their σ� values, while -R substituents react more slowly than predicted. Measurement of rates of cleavage of three series of unsymmetrically substituted disulphides by cyanide or hydroxide shows that these unusual substituent effects arise from substituents in the thiocyanate-forming aryl ring. This behaviour is explained in terms of a change in the electronic behaviour of the thio- cyanate-forming sulphur atom from -I, + R in the disulphide to -I,-R in the rate-determining transition state for the reaction. The study does not show whether the cleavage involves an SN2 process or rapid equilibrium formation of a pentacovalent intermediate.

Unprecedented Copper(II) Coordination Induced Nucleophilic Cleavage of Quinoxaline Heterocycle: Structural and Computational Studies

CrystEngComm ◽  
2021 ◽  
Author(s):  
Bhaskar Biswas ◽  
Nilaj Banerjee ◽  
Mayank Joshi ◽  
Stevan Armaković ◽  
Sanja J Armaković ◽  
...  
Keyword(s):  
Synthetic Approach ◽  
Computational Studies ◽  
Quinoxaline Derivative ◽  
Catalyst Free ◽  
Nucleophilic Cleavage

A straightforward catalyst-free synthetic approach has been developed for the synthesis of quinoxaline derivative, 4-phenyl-4-(pyridin-2-yl)-4,5-dihydropyrrolo[1,2-a]quinoxaline (L) by the reaction of 2-benzoyl pyridine and pyrrole-1-anillin in ethanol. The L in presence...

ChemInform Abstract: Some Specific Features of Acid Nitration of 2-Substituted 4,6-Dihydroxypyrimidines. Nucleophilic Cleavage of the Nitration Products.

ChemInform ◽  
2010 ◽  
Vol 32 (51) ◽  
pp. no-no
Author(s):  
A. A. Astrat'ev ◽  
D. V. Dashko ◽  
A. Yu. Mershin ◽  
A. I. Stepanov ◽  
N. A. Urazgil'deev
Keyword(s):  
Nucleophilic Cleavage
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