N-Heterocyclic olefins as efficient phase-transfer catalysts for base-promoted alkylation reactions

2016 ◽  
Vol 52 (51) ◽  
pp. 7958-7961 ◽  
Author(s):  
Marcus Blümel ◽  
Reece D. Crocker ◽  
Jason B. Harper ◽  
Dieter Enders ◽  
Thanh V. Nguyen

N-Heterocyclic olefins (NHOs) chemically transfer the base from solid phase and promote alkylation reaction on a wide range of substrates.

2011 ◽  
Vol 7 ◽  
pp. 119-126 ◽  
Author(s):  
Heiko Ihmels ◽  
Jia Luo

Dibenzobarrelene derivatives, that are annelated with a pyrrolinium unit [N,N-dialkyl-3,4-(9',10'-dihydro-9',10'-anthraceno-3-pyrrolinium) derivatives], undergo a photo-induced di-π-methane rearrangement upon triplet sensitization to give the corresponding cationic dibenzosemibullvalene derivatives [N,N-dialkyl-3,4-{8c,8e-(4b,8b-dihydrodibenzo[a,f]cyclopropa[cd]pentaleno)}pyrrolidinium derivatives]. Whereas the covalent attachment of a benzophenone functionality to the pyrrolinium nitrogen atom did not result in an internal triplet sensitization, the introduction of a benzophenone unit as part of the counter ion enables the di-π-methane rearrangement of the dibenzobarrelene derivative in the solid-state. Preliminary experiments indicate that a cationic pyrrolidinium-annelated dibenzosemibullvalene may act as phase-transfer catalyst in alkylation reactions.


2016 ◽  
Vol 14 (42) ◽  
pp. 10101-10109 ◽  
Author(s):  
Ponmuthu Kottala Vijaya ◽  
Sepperumal Murugesan ◽  
Ayyanar Siva

Newly synthesized CPTCs are applied in the asymmetric Henry reaction to a wide range of aldehydes under mild reaction conditions, and we obtained higher chemical yields and an excellent enantiomeric excess.


ChemInform ◽  
2016 ◽  
Vol 47 (44) ◽  
Author(s):  
Marcus Bluemel ◽  
Reece D. Crocker ◽  
Jason B. Harper ◽  
Dieter Enders ◽  
Thanh V. Nguyen

2004 ◽  
Vol 69 (2) ◽  
pp. 85-92 ◽  
Author(s):  
Dusan Mijin ◽  
Vida Jankovic ◽  
Slobodan Petrovic

Benzylation of N-(4-chlorophenyl)-2-phenylacetamidewith benzyl chloride in the presence of powdered potassium hydroxide under various reaction conditions was performed in order to establish the possible reaction products. Different temperatures and ratios of reactants and solvents were used. The reactions were also carried out in the presence of different phase-transfer catalysts in toluene as a solvent. The formation of the reaction products was followed using gas chromatography. On the basis of the obtained results, the reactivity and the orientation in the alkylation reaction of the investigated amide is discussed.


1997 ◽  
pp. 87-95 ◽  
Author(s):  
Fernando Varona ◽  
Federico Mijangos ◽  
Jose I. Lombraña ◽  
Mario Díaz

2000 ◽  
Vol 35 (2) ◽  
pp. 245-262 ◽  
Author(s):  
Francis I. Onuska ◽  
Ken A. Terry ◽  
R. James Maguire

Abstract The analysis of aromatic amines, particularly benzidines, at trace levels in environmental media has been difficult because of the lack of suitable deactivated capillary column stationary phases for gas chromatography. This report describes the use of an improved type of column as well as a method for the analysis of anilines and benzidines in water, wastewater and sewage samples. Extraction procedures are applicable to a wide range of compounds that are effectively partitioned from an aqueous matrix into methylene chloride, or onto a solid-phase extraction cartridge. The extracted analytes are also amenable to separation on a capillary gas chromatographic column and transferable to the mass spectrometer. These contaminants are converted to their N-trifluoroacetyl derivatives. Aniline and some substituted anilines, and 3,3’-dichlorobenzidine and benzidine were determined in 24-h composite industrial water, wastewater, primary sludge and final effluent samples at concentrations from 0.03 up to 2760 µg/L.


2019 ◽  
Vol 23 (6) ◽  
pp. 643-678
Author(s):  
Lalthazuala Rokhum ◽  
Ghanashyam Bez

Recent years have witnessed a fast development of solid phase synthetic pathways, a variety of solid-supported reagent and its applications in diverse synthetic strategies and pharmaceutical applicability’s. Polymer-supported triphenylphosphine is getting a lot of applications owing to the speed and simplicity in the process. Furthermore, ease of recyclability and reuse of polymer-supported triphenylphosphine added its advantages. This review covers a wide range of useful organic transformations which are accomplished using cross-linked polystyrene-supported triphenylphosphine with the aim of giving renewed interest in the field of organic and medicinal-combinatorial chemistry.


2020 ◽  
Vol 17 (4) ◽  
pp. 405-411
Author(s):  
Chuan-Hui Wang ◽  
Chen-Fu Liu ◽  
Guo-Wu Rao

Oxidation reactions have emerged as one of the most versatile tools in organic chemistry. Various onium salts such as ammonium, phosphonium, arsonium, bismuthonium, tellurium have been used as phase transfer catalysts in many oxidation reactions. Certainly, considerable catalysts have been widely used in Phase-Transfer Catalysis (PTC). This review focuses on the application of PTC in various oxidation reaction. Furthermore, PTC also conforms to the concept of “Green Chemistry”. <p></p> • Oxidation has become one of the most widely used tools in organic chemistry and phase transfer catalysts has been widely used in oxidation. <p></p> • The application of phase transfer catalysts in oxidation reaction will be summarized. <p></p> • Phase transfer catalysts have important application in various oxidation reaction.


2020 ◽  
Vol 07 ◽  
Author(s):  
Neslihan Demirbas ◽  
Ahmet Demirbas

Background: Since the discovery of metal-free catalysts or organocatalysts about twenty years ago, a number of small molecules with different structures have been using to accelerate organic transformations. With the development of environmental awareness, in order to obtain highly privileged scaffolds, scientists have directed their studies towards the synthetic methodologies which minimize or preferably eliminate the formation of waste, avoid from toxic solvents and reagents and use renewable starting materials as far as possible. Methods: In this connection, the organocatalytic reactions providing efficiency and selectivity for most of case have become an endless topic in organic chemistry since several advantages from both practical and environmental standpoints. Organocatalysts supplying transformation of reactants into products with the least possible waste production have been serving to the concept of green chemistry. Results and Conclusion: Organocatalysts have been classified on the basis of their binding capacity to the substrate with covalently or noncovalent interactions involving hydrogen bonding and electrostatic interaction. Diverse types of small organic compounds including proline and its derivatives, phase-transfer catalysts, (thio)urease, phosphoric acids, sulfones, N-oxides, guanidines, cinchona derivatives, aminoindanol and amino acids have been utilized as hydrogen bonding organocatalysts in different chemical transformations.


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