scholarly journals Leaving Group Ability in Nucleophilic Aromatic Amination by Sodium Hydride–Lithium Iodide Composite

Synthesis ◽  
2019 ◽  
Vol 52 (03) ◽  
pp. 393-398
Author(s):  
Jia Hao Pang ◽  
Derek Yiren Ong ◽  
Kohei Watanabe ◽  
Ryo Takita ◽  
Shunsuke Chiba
Keyword(s):  
Nucleophilic Substitution ◽  
Methoxy Group ◽  
Sodium Hydride ◽  
Lithium Iodide ◽  
Substitution Reactions ◽  
Computational Approaches ◽  
Nucleophilic Substitution Reactions ◽  
Leaving Group ◽  
Leaving Group Ability

The methoxy group is generally considered as a poor leaving group for nucleophilic substitution reactions. This work verified the superior ability of the methoxy group in nucleophilic amination of arenes mediated by the sodium hydride and lithium iodide through experimental and computational approaches.

Correlation of isotope effects in substitution reactions with nucleophilicities. Secondary α-deuterium isotope effect in the iodide-131 exchange of methyl-d3 iodide

1967 ◽  
Vol 45 (18) ◽  
pp. 2023-2031 ◽  
Author(s):  
Stanley Seltzer ◽  
Andreas A. Zavitsas
Keyword(s):  
Nucleophilic Substitution ◽  
Isotope Effect ◽  
Isotope Effects ◽  
Substitution Reactions ◽  
Deuterium Isotope Effect ◽  
Nucleophilic Substitution Reactions ◽  
Leaving Group ◽  
The Difference

The secondary α-deuterium isotope effect in iodide-131 exchange of methyl-d3 iodide is kH/kD = 1.05 ± 0.01 in methanol and 1.10 ± 0.04 in water at 20°. A correlation of secondary α-deuterium and 13C effects, in bimolecular nucleophilic substitution reactions, with the difference of E values between nucleophile and leaving group is presented.

Potential antidepressants: 4-(Thioaryloxy)piperidines

1989 ◽  
Vol 54 (8) ◽  
pp. 2240-2247 ◽  
Author(s):  
Karel Šindelář ◽  
Marta Hrubantová ◽  
Emil Svátek ◽  
Oluše Matoušová ◽  
Jiřina Metyšová ◽  
...  
Keyword(s):  
Nucleophilic Substitution ◽  
Sodium Hydride ◽  
Antidepressant Activity ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
Behavioural Tests

Nucleophilic substitution reactions of a series of thio-substituted fluoroarenes with 1-methyl-4-piperidinol, 1-benzyl-4-piperidinol, and 1-methyl-4-phenyl-4-piperidinol in the presence of sodium hydride in dimethylformamide gave the title compounds V-XI and XIII. The salts of these bases were pharmacologically tested and salts of compounds V, XI, and XIII showed in behavioural tests properties which are indicative of antidepressant activity.

Isotope effects in nucleophilic substitution reactions. III. The effect of changing the leaving group on transition state structure in SN2 reactions

1979 ◽  
Vol 57 (11) ◽  
pp. 1354-1367 ◽  
Author(s):  
Kenneth Charles Westaway ◽  
Syed Fasahat Ali
Keyword(s):  
Transition State ◽  
Nucleophilic Substitution ◽  
Isotope Effects ◽  
Heavy Atom ◽  
Substituent Effects ◽  
Kinetic Isotope Effects ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
Kinetic Isotope ◽  
Leaving Group

The nucleophilic substitution reactions of a series of 4-substituted phenylbenzyldimethyl-ammonium ions with thiophenoxide ions at 0 °C in N,N-dimethylformamide have been used to demonstrate how a change in the leaving group alters the structure of the SN2 transition state. Heavy atom (nitrogen) kinetic isotope effects, secondary α-deuterium kinetic isotope effects and Hammett ρ values provide qualitative descriptions of both the nucleophile–α-carbon and α-carbon–leaving group bonds in the transition states of these reactions. The results indicate that changing to a better leaving group causes the bond between the α-carbon and the nucleophile to be much more fully formed while the bond to the leaving group is essentially unchanged. The results are discussed in the light of current theories of substituent effects on SN2 reactions and a possible explanation for the surprising results (i) that the greatest effect is in the bond more remote from the point of structural change and (ii) that more nucleophilic assistance is required to displace a better leaving group is given.

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