scholarly journals Ionic, Core-Corona Polymer Microsphere-Immobilized MacMillan Catalyst for Asymmetric Diels-Alder Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 960
Author(s):  
Md. Wali Ullah ◽  
Naoki Haraguchi
Keyword(s):  
Catalytic Activity ◽  
Enantiomeric Excess ◽  
Alder Reaction ◽  
Significant Loss ◽  
Diels Alder ◽  
Polymer Support ◽  
Polymer Microsphere ◽  
Chiral Catalyst ◽  
Ionic Core ◽  
Critical Issues

The improvement of the catalytic activity of a heterogeneous chiral catalyst is one of the most critical issues, as are its recovery and reuse. The design of a heterogeneous chiral catalyst, including the immobilization method and the support polymer, is of significance for the catalytic activity in asymmetric reactions. An ionic, core-corona polymer microsphere-immobilized MacMillan catalyst (ICCC) was successfully synthesized by the neutralization reaction of sulfonic acid functionalized core-corona polymer microsphere (CCM–SO3H) with a chiral imidazolidinone precursor. We selected the core-corona polymer microsphere as the polymer support for the improvement of catalytic activity and recovery. The MacMillan catalyst was immobilized onto the pendant position of the corona with ionic bonding. ICCC exhibited excellent enantioselectivity up to 92% enantiomeric excess (ee) (exo) and >99% ee (endo) in the asymmetric Diels-Alder (DA) reaction of (E)-cinnamaldehyde and 1,3-cyclopentadiene. ICCC was quantitatively recovered by centrifugation because of the microsphere structure. The recovered ICCC was reused without significant loss of the enantioselectivity.

scholarly journals Borenium ionic liquids as catalysts for Diels–Alder reaction: tuneable Lewis superacids for catalytic applications

2017 ◽  
Vol 7 (5) ◽  
pp. 1045-1049 ◽  
Author(s):  
K. Matuszek ◽  
S. Coffie ◽  
A. Chrobok ◽  
M. Swadźba-Kwaśny
Keyword(s):  
Catalytic Activity ◽  
Ionic Liquids ◽  
Alder Reaction ◽  
Diels Alder ◽  
Lewis Acidity ◽  
High Catalytic Activity ◽  
Acceptor Number ◽  
Diels Alder Reaction ◽  
Catalytic Applications

Ionic liquids with Lewis superacidic borenium cations were used as catalysts in solvent-less Diels–Alder cycloaddition. The extremely high catalytic activity correlated with the Lewis acidity, expressed as the Gutmann acceptor number.

Lanthanide catalysts for the hetero Diels–Alder reaction: effect of ligand structure and acidity

1997 ◽  
Vol 75 (8) ◽  
pp. 1047-1054 ◽  
Author(s):  
Claude Spino ◽  
Laurel L. Clouston ◽  
David J. Berg
Keyword(s):  
Catalytic Activity ◽  
Vinyl Ether ◽  
Alder Reaction ◽  
Diels Alder ◽  
Ethyl Vinyl Ether ◽  
Ethyl Vinyl ◽  
Catalytic Activities ◽  
Ligand Structure ◽  
Bite Angle ◽  
Diels Alder Reaction

A series of yttrium, ytterbium, and lanthanum hexa-or heptacoordinate complexes were prepared and their catalytic activities tested in the hetero Diels–Alder reaction between crotonaldehyde and ethyl vinyl ether. It was found that a pKa below 7 of the ligand was necessary but not sufficient for catalytic activity. It was determined that the ligand should possess a perfluoromethyl-β-diketonate functionality. Other factors such as bite angle and hinging motion may also play a determining role. Keywords: lanthanide, catalyst, hetero Dielsis–Alder, yttrium, ytterbium, lanthanum.

Critical issues in the surface modification of active carbons by the Diels–Alder reaction

2013 ◽  
Vol 101 ◽  
pp. 17-20
Author(s):  
Katarzyna Łukaszuk ◽  
Aleksandra Cyganiuk ◽  
Mirosław Wełniak ◽  
Jerzy P. Łukaszewicz
Keyword(s):  
Surface Modification ◽  
Alder Reaction ◽  
Diels Alder ◽  
Active Carbons ◽  
Diels Alder Reaction ◽  
Critical Issues

Asymmetric Diels—Alder Reaction Using Pyrazole Derivatives as a Chiral Catalyst.

ChemInform ◽  
2004 ◽  
Vol 35 (2) ◽  
Author(s):  
Choji Kashima ◽  
Yohei Miwa ◽  
Saori Shibata ◽  
Hiroyuki Nakazono
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Pyrazole Derivatives ◽  
Chiral Catalyst ◽  
Diels Alder Reaction

scholarly journals New L-Serine Derivative Ligands as Cocatalysts for Diels-Alder Reaction

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Carlos A. D. Sousa ◽  
José E. Rodríguez-Borges ◽  
Cristina Freire
Keyword(s):  
Catalytic Activity ◽  
Lewis Acids ◽  
Alder Reaction ◽  
Diels Alder ◽  
Reaction Yield ◽  
Catalytic Potential ◽  
Diels Alder Reaction ◽  
Good Ability ◽  
Medium Strength

New L-serine derivative ligands were prepared and tested as cocatalyst in the Diels-Alder reactions between cyclopentadiene (CPD) and methyl acrylate, in the presence of several Lewis acids. The catalytic potential of the in situ formed complexes was evaluated based on the reaction yield. Bidentate serine ligands showed good ability to coordinate medium strength Lewis acids, thus boosting their catalytic activity. The synthesis of the L-serine ligands proved to be highly efficient and straightforward.

Asymmetric diels alder reaction using pyrazole derivatives as a chiral catalyst

2003 ◽  
Vol 40 (4) ◽  
pp. 681-688 ◽  
Author(s):  
Choji Kashima ◽  
Yohei Miwa ◽  
Saori Shibata ◽  
Hiroyuki Nakazono
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Pyrazole Derivatives ◽  
Chiral Catalyst ◽  
Diels Alder Reaction
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