Substitution reaction

AccessScience ◽  
2015 ◽  
Keyword(s):  
Substitution Reaction

Outer-sphere interaction of (S)-asparagine and (S)-glutamine with [Co(NH3)6]3+ ion and its possible role in ligand substitution

1987 ◽  
Vol 52 (10) ◽  
pp. 2457-2459
Author(s):  
František Jursík
Keyword(s):  
Amino Acids ◽  
Transition Region ◽  
Alkaline Medium ◽  
Optical Activity ◽  
Substitution Reaction ◽  
Outer Sphere ◽  
Ligand Substitution ◽  
Cotton Effect ◽  
Negative Cotton Effect

Optical activity of the achiral cation [Co(NH3)6]3+ is induced both by (S)-AsnONa and (S)-GlnONa, as shown by a negative Cotton effect in the 1A1g → 1T1g transition region. An outer-sphere interaction by three-point attachment of the amides can explain the fact that substitution reaction of [Co(NH3)6]3+ with the mentioned amides in an alkaline medium is unusually slow as compared with other amino acids.

Fluorinated analogues of tricyclic neuroleptics: 6,9-difluoro derivative of 10-(4-methylpiperazino)-10,11-dihydrodibenzo[b,f]thiepin

1980 ◽  
Vol 45 (10) ◽  
pp. 2688-2694 ◽  
Author(s):  
Irena Červená ◽  
Marta Hrubantová ◽  
Emil Svátek ◽  
Jiří Holubek ◽  
Miroslav Ryska ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Title Compound ◽  
Substitution Reaction ◽  
Polyphosphoric Acid ◽  
Satisfactory Yield ◽  
Chloro Derivative ◽  
Cns Activity

The acid VI, obtained from 2,5-difluorothiophenol (IV) and (2-iodophenyl)acetic acid, afforded by cyclization with polyphosphoric acid 6,9-difluorodibenzo[b,f]thiepin-10(11H)-one (VII) in a satisfactory yield. Two further steps led to the chloro derivative X giving by a substitution reaction with 1-methylpiperazine the title compound III. This substance exhibits some 10% incoordinating activity of the unsubstituted compound I and an indication of cataleptic activity, in contrast to the inactive analogous dichloro compound II. The bulky atom of chlorine in the vicinity of the methylpiperazine residue interferes evidently with the CNS activity; the influence of the atom of fluorine is much less pronounced in this line.

scholarly journals Synthesis of Carbohydrate Based Macrolactones and Their Applications as Receptors for Ion Recognition and Catalysis

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3394
Author(s):  
Surya B. Adhikari ◽  
Anji Chen ◽  
Guijun Wang
Keyword(s):  
Nucleophilic Substitution ◽  
Supramolecular Chemistry ◽  
Copper Sulfate ◽  
Substitution Reaction ◽  
Biological Properties ◽  
Anion Binding ◽  
Nucleophilic Substitution Reaction ◽  
Binding Properties ◽  
Intramolecular Nucleophilic Substitution ◽  
Leaving Groups

Glycomacrolactones exhibit many interesting biological properties, and they are also important in molecular recognitions and for supramolecular chemistry. Therefore, it is important to be able to access glycomacrocycles with different sizes and functionality. A new series of carbohydrate-based macrocycles containing triazole and lactone moieties have been designed and synthesized. The synthesis features an intramolecular nucleophilic substitution reaction for the macrocyclization step. In this article, the effect of some common sulfonate leaving groups is evaluated for macrolactonization. Using tosylate gave good selectivity for monolactonization products with good yields. Fourteen different macrocycles have been synthesized and characterized, of which eleven macrocycles are from cyclization of the C1 to C6 positions of N-acetyl D-glucosamine derivatives and three others from C2 to C6 cyclization of functionalized D-glucosamine derivatives. These novel macrolactones have unique structures and demonstrate interesting anion binding properties, especially for chloride. The macrocycles containing two triazoles form complexes with copper sulfate, and they are effective ligands for copper sulfate mediated azide-alkyne cycloaddition reactions (CuAAC). In addition, several macrocycles show some selectivity for different alkynes.

Enantioselective Nucleophilic Aromatic Substitution Reaction of Azlactones to Synthesize Quaternary α-Amino Acid Derivatives

Synlett ◽  
2020 ◽  
Author(s):  
Xiaohua Liu ◽  
Yi Li ◽  
Hao Pan ◽  
Wang-Yuren Li ◽  
Xiaoming Feng
Keyword(s):  
Hydrogen Bonding ◽  
Charge Transfer ◽  
Amino Acid ◽  
Substitution Reaction ◽  
Nucleophilic Aromatic Substitution ◽  
Amino Acid Derivatives ◽  
Amino Acid Esters ◽  
Aromatic Substitution ◽  
Charge Transfer Interaction ◽  
Acid Esters

AbstractAn asymmetric organocatalytic nucleophilic aromatic substitution reaction of azlactones with electron-deficient aryls was established. A variety of α-aryl α-alkyl α-amino acid esters and peptides were obtained in decent yields and stereoselectivities. A new bifunctional catalytic mode involving charge-transfer interaction and hydrogen bonding is proposed to explain the enantioselectivity.

scholarly journals Biocompatible ionic liquid [Betaine][H2PO4] as a reusable catalyst for the substitution of xanthen-9-ol under solvent-free conditions

RSC Advances ◽  
2020 ◽  
Vol 10 (52) ◽  
pp. 31662-31669
Author(s):  
Anlian Zhu ◽  
Tong Wang ◽  
Wanlu Feng ◽  
Jianji Wang ◽  
Lingjun Li
Keyword(s):  
Ionic Liquid ◽  
Substitution Reaction ◽  
Solvent Free ◽  
Reusable Catalyst ◽  
Solvent Free Conditions ◽  
Direct Substitution

A cheap and biocompatible ionic liquid [Betaine][H2PO4] was found to be an efficient and reusable catalyst for the direct substitution reaction of xanthen-9-ol under solvent-free conditions.

Lewis-Acid-Catalyzed Direct Nucleophilic Substitution Reaction of Alcohols for the Functionalization of Aromatic Amines

2019 ◽  
Vol 4 (4) ◽  
pp. 1371-1374 ◽  
Author(s):  
Onkar S. Nayal ◽  
Maheshwar S. Thakur ◽  
Rohit Rana ◽  
Rahul Upadhyay ◽  
Sushil K. Maurya
Keyword(s):  
Nucleophilic Substitution ◽  
Lewis Acid ◽  
Aromatic Amines ◽  
Substitution Reaction ◽  
Nucleophilic Substitution Reaction ◽  
Acid Catalyzed
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