scholarly journals Synthesis of cationic dibenzosemibullvalene-based phase-transfer catalysts by di-π-methane rearrangements of pyrrolinium-annelated dibenzobarrelene derivatives

2011 ◽  
Vol 7 ◽  
pp. 119-126 ◽  
Author(s):  
Heiko Ihmels ◽  
Jia Luo
Keyword(s):  
Solid State ◽  
Nitrogen Atom ◽  
Phase Transfer ◽  
Phase Transfer Catalyst ◽  
Covalent Attachment ◽  
Phase Transfer Catalysts ◽  
Counter Ion ◽  
Alkylation Reactions

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.

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
Keyword(s):  
Phase Transfer ◽  
Solid Phase ◽  
Alkylation Reaction ◽  
Phase Transfer Catalysts ◽  
Wide Range ◽  
Alkylation Reactions

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

scholarly journals Synthesis of Novel Crown Ether-Squaramides and Their Application as Phase-Transfer Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6542
Author(s):  
Zsuzsanna Fehér ◽  
Dóra Richter ◽  
Sándor Nagy ◽  
Péter Bagi ◽  
Zsolt Rapi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Nitrogen Atom ◽  
Crown Ether ◽  
Phase Transfer ◽  
Addition Reactions ◽  
Green Solvents ◽  
Malonic Ester ◽  
Phase Transfer Catalysts ◽  
Stereogenic Center ◽  
New Phase

This work presents the synthesis of six new phase-transfer organocatalysts in which the squaramide unit is directly linked to the nitrogen atom of an aza-crown ether. Four chiral skeletons, namely hydroquinine, quinine, cinchonine (cinchonas), and α-d-glucopyranoside were responsible for the asymmetric construction of an all-carbon quaternary stereogenic center in α-alkylation and Michael addition reactions of malonic esters. We investigated the effects of these different chiral units and that of crown ethers with different sizes on catalytic activity and enantioselectivity. During extensive parameter investigations, both conventional and emerging green solvents were screened, providing valuable α,α-disubstituted malonic ester derivatives with excellent yields (up to 98%).

Asymmetric synthesis of 3-phenyl-2,3-dihydro-1H-pyrrolo[3,2-b]pyridine-3-carbonitriles catalysed by phase transfer catalyst derived from tert-leucine.

Synlett ◽  
2021 ◽  
Author(s):  
Zhiqi Zhao ◽  
Jingdong Wang ◽  
lin zhong wei ◽  
gang jun cao ◽  
peng da liang ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Phase Transfer ◽  
Phase Transfer Catalyst ◽  
Chiral Phase ◽  
Phase Transfer Catalysts ◽  
Excellent Yield ◽  
Chiral Phase Transfer Catalysts

Chiral phase transfer catalysts derived from tert-leucine were synthesized and used in the aymmetric synthesis of 4-azaindoline derivatives. By this method, both enantiomers of corresponding products were obtained in excellent yield (up to 99%) with high enantioselectivity (up to 91% ee) and diastereoselectivity (up to >99: 1 dr).

ChemInform Abstract: N-Heterocyclic Olefins as Efficient Phase-Transfer Catalysts for Base-Promoted Alkylation Reactions.

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

ANIONIC ION EXCHANGERS AS PHASE TRANSFER CATALYSTS IN ALKYLATION REACTIONS

1997 ◽  
pp. 87-95 ◽  
Author(s):  
Fernando Varona ◽  
Federico Mijangos ◽  
Jose I. Lombraña ◽  
Mario Díaz
Keyword(s):  
Phase Transfer ◽  
Ion Exchangers ◽  
Phase Transfer Catalysts ◽  
Alkylation Reactions

New quaternary phosphonium salt as multi-site phase-transfer catalyst for various alkylation reactions

2016 ◽  
Vol 42 (12) ◽  
pp. 8345-8358
Author(s):  
Kottala Vijaya Ponmuthu ◽  
Duraimurugan Kumaraguru ◽  
Jesin Beneto Arockiam ◽  
Sadhasivam Velu ◽  
Murugesan Sepperumal ◽  
...  
Keyword(s):  
Phosphonium Salt ◽  
Phase Transfer ◽  
Phase Transfer Catalyst ◽  
Quaternary Phosphonium Salt ◽  
Alkylation Reactions

Divergent synthesis of pyrrolidine and glutamic acid derivatives using macrocyclic phase-transfer catalyst under high-pressure conditions

2021 ◽  
Author(s):  
Agata Tyszka-Gumkowska ◽  
Janusz Jurczak
Keyword(s):  
High Pressure ◽  
Glutamic Acid ◽  
Phase Transfer ◽  
Phase Transfer Catalyst ◽  
Unsaturated Ketones ◽  
Phase Transfer Catalysts ◽  
Glutamic Acid Derivatives

The reactivity of the glycine ketimine ester with α,β-unsaturated ketones in the presence of macrocyclic hybrid phase-transfer catalysts under high pressure conditions has been investigated. Control during reactions, obtained through...

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