scholarly journals Stereocontrolled asymmetric synthesis

2000 ◽  
Vol 72 (9) ◽  
pp. 1691-1697 ◽  
Author(s):  
Yong Hae Kim ◽  
Sam Min Kim ◽  
Doo Han Park ◽  
So Won Youn
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Diels Alder ◽  
Samarium Diiodide ◽  
Coupling Reactions ◽  
Asymmetric Syntheses ◽  
Pinacol Coupling ◽  
First Time

Stereo differentiated asymmetric syntheses have been achieved by S-indoline derivations. Diels-Alder cycloadditions of S-indoline chiral acrylamides with cyclopentadiene proceed with high diastereofacial selectivity, giving either endo-R or endo-S products depending on Lewis acid and the structures of chiral dienophiles. Diastereo- and enantio-selective pinacol coupling reactions of chiral α-ketoamides mediated by samarium diiodide afforded extremely high diastereoselectivities. Enantiopure (S,S)- or (R,R)-2,3-dialkyltar-taric acid and derivatives can be synthesized for the first time depending on the structure of α-ketoamides.

Asymmetric synthesis by stereocontrol

2001 ◽  
Vol 73 (2) ◽  
pp. 283-286 ◽  
Author(s):  
Yong Hae Kim ◽  
Sam Min Kim ◽  
So Won Youn
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Lewis Acids ◽  
Diels Alder ◽  
Samarium Diiodide ◽  
Coupling Reactions ◽  
Pinacol Coupling

Diels-Alder cycloadditions of S-indoline chiral acrylamides with cyclopentadiene in the presence of Lewis acids proceed with high diastereofacial selectivity, giving either endo-R or endo-S products depending on Lewis acid and the structures of chiral dienophiles. Diastereo- and enantioselective pinacol coupling reactions of chiral α-ketoamides mediated by samarium diiodide afforded extremely high diastereoselectivities. Enantiopure (S,S) - or (R,R) -2,3-dialkyltartaric acid and derivatives can be synthesized. Furthermore, it was demonstrated that α,β-unsaturated amides coupled with SmI2 to dimerized products containing two chiral carbons which were first obtained as the adjacent chiral carbons.

scholarly journals Dual enantioselective control by heterocycles of (S)-indoline derivatives

2005 ◽  
Vol 77 (12) ◽  
pp. 2053-2059 ◽  
Author(s):  
Yong Hae Kim ◽  
Doo Young Jung ◽  
So Won Youn ◽  
Sam Min Kim ◽  
Doo Han Park
Keyword(s):  
Lewis Acid ◽  
Lewis Acids ◽  
Diels Alder ◽  
Samarium Diiodide ◽  
Coupling Reactions ◽  
Pinacol Coupling

Diastereo-and enantioselective pinacol coupling reactions of chiral α-ketoamides mediated by samarium diiodide afforded extremely high diastereoselectivities. Enantiopure (S,S)- or (R,R)-2,3-dialkyltartaric acid and derivatives can be synthesized. Diels-Alder cycloadditions of S-indoline chiral acrylamides with cyclopentadiene in the presence of Lewis acids proceed with high diastereofacial selectivity, giving either endo-R or endo-S products depending on Lewis acid and the structures of chiral dienophiles.

Enantioselective Syntheses of Flavonoid Diels-Alder Natural Products: A Review

2018 ◽  
Vol 15 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Shah Bakhtiar Nasir ◽  
Noorsaadah Abd Rahman ◽  
Chin Fei Chee
Keyword(s):  
Natural Products ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Enantioselective Synthesis ◽  
Chiral Ligand ◽  
Asymmetric Syntheses ◽  
Diels Alder Reaction ◽  
Enantioselective Syntheses

Background: The Diels-Alder reaction has been widely utilised in the syntheses of biologically important natural products over the years and continues to greatly impact modern synthetic methodology. Recent discovery of chiral organocatalysts, auxiliaries and ligands in organic synthesis has paved the way for their application in Diels-Alder chemistry with the goal to improve efficiency as well as stereochemistry. Objective: The review focuses on asymmetric syntheses of flavonoid Diels-Alder natural products that utilize chiral ligand-Lewis acid complexes through various illustrative examples. Conclusion: It is clear from the review that a significant amount of research has been done investigating various types of catalysts and chiral ligand-Lewis acid complexes for the enantioselective synthesis of flavonoid Diels-Alder natural products. The results have demonstrated improved yield and enantioselectivity. Much emphasis has been placed on the synthesis but important mechanistic work aimed at understanding the enantioselectivity has also been discussed.

Asymmetric synthesis of N-phenylethyl-2-phenyldecahydroquinolin-4-ones via Lewis acid catalyzed imino-Diels–Alder reaction

2000 ◽  
Vol 11 (12) ◽  
pp. 2509-2523 ◽  
Author(s):  
Renée Paugam ◽  
Emmanuelle Valenciennes ◽  
Linda Le Coz-Bardol ◽  
Jean-Christophe Garde ◽  
Lya Wartski ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Acid Catalyzed

Asymmetric synthesis of isoquinuclidines by Diels–Alder reaction of 1,2-dihydropyridine utilizing a chiral Lewis acid catalyst

Tetrahedron ◽  
2012 ◽  
Vol 68 (6) ◽  
pp. 1774-1781 ◽  
Author(s):  
Chigusa Seki ◽  
Masafumi Hirama ◽  
N.D.M. Romauli Hutabarat ◽  
Junko Takada ◽  
Chonticha Suttibut ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Acid Catalyst ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Chiral Lewis Acid ◽  
Lewis Acid Catalyst

ChemInform Abstract: Studies in Asymmetric Synthesis. Part 4. Studies in Lewis Acid and LiClO4 (or Nafion-H) Catalyzed Ionic Diels-Alder Reactions of Chiral and Achiral Olefinic Acetals Respectively.

ChemInform ◽  
2010 ◽  
Vol 30 (27) ◽  
pp. no-no
Author(s):  
R. Kumareswaran ◽  
Padma S. Vankar ◽  
M. Venkat Ram Reddy ◽  
Sangeeta V. Pitre ◽  
Raja Roy ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Diels Alder

scholarly journals Synthesis of Stilbenes Using Various Catalysts and Investigation of their Optical Properties

2021 ◽  
Author(s):  
Pelin Ulukan ◽  
Saron Catak ◽  
Erdal Ertas
Keyword(s):  
Optical Properties ◽  
Lewis Acid ◽  
Suzuki Coupling ◽  
Acid Catalysts ◽  
Coupling Reactions ◽  
Lewis Acid Catalysts ◽  
First Time

Stilbenes substituted with –CN, –OMe and –Br were synthesized using four different Lewis acid catalysts and their reaction efficiencies were compared. In addition to McMurry reagents known in literature, a more familiar and economical catalyst ZnCl2 was used for the first time in our reaction procedures. Furthermore, bromine substituted stilbenes were subjected to Suzuki coupling reactions to append a triphenylamine (TPA) unit, which enhances fluorescence emissions. Solvatochromic properties of synthesized stilbenes were investigated and aggregation caused quenching (ACQ) properties of TPA containing molecules were systematically examined. Optical properties were also theoretically investigated.

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