Imidazolinium and amidinium salts as Lewis acid organocatalysts

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.8.205 ◽

2012 ◽

Vol 8 ◽

pp. 1798-1803 ◽

Cited By ~ 13

Author(s):

Oksana Sereda ◽

Nicole Clemens ◽

Tatjana Heckel ◽

René Wilhelm

Keyword(s):

Lewis Acid ◽

Ring Opening ◽

Alder Reaction ◽

Diels Alder ◽

Diels Alder Reaction

The application of imidazolinium and amidinium salts as soft Lewis acid organocatalysts is described. These salts were suitable catalysts for the activation of unsaturated thioesters in a Diels–Alder reaction and in the ring opening of thiiranes and epoxides. The products were isolated in good yields. The mild catalysts did not cause desulfurization of the products containing a thiol or thiocarbonyl group.

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Synthesis of Medium-Sized Carbocycles via a Bidentate Lewis Acid-Catalyzed Inverse Electron-Demand Diels–Alder Reaction Followed by Photoinduced Ring-Opening

Organic Letters ◽

10.1021/acs.orglett.1c00249 ◽

2021 ◽

Author(s):

Julia Ruhl ◽

Sebastian Ahles ◽

Marcel A. Strauss ◽

Christopher M. Leonhardt ◽

Hermann A. Wegner

Keyword(s):

Lewis Acid ◽

Ring Opening ◽

Alder Reaction ◽

Diels Alder ◽

Inverse Electron Demand ◽

Diels Alder Reaction ◽

Acid Catalyzed ◽

Electron Demand

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

Current Organic Synthesis ◽

10.2174/1570179414666170821120234 ◽

2018 ◽

Vol 15 (2) ◽

pp. 221-229 ◽

Cited By ~ 3

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.

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