Mechanistic studies on the formal aza-Diels–Alder reactions of N-aryl imines: evidence for the non-concertedness under Lewis-acid catalysed conditions

2004 ◽  
Vol 2 (17) ◽  
pp. 2451-2460 ◽  
Author(s):  
Stephen Hermitage ◽  
Judith A. K. Howard ◽  
David Jay ◽  
Robin G. Pritchard ◽  
Michael R. Probert ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Diels Alder ◽  
Mechanistic Studies

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.

Intramolecular Diels–Alder Reactions of Oxazoles, Imidazoles, and Thiazoles

Synthesis ◽  
2020 ◽  
Author(s):  
Peter Wipf ◽  
Thanh T. Nguyen
Keyword(s):  
Natural Products ◽  
Lewis Acid ◽  
Acid Catalysis ◽  
Copper Catalysts ◽  
Diels Alder ◽  
Synthetic Approach ◽  
Highly Efficient ◽  
Intramolecular Cycloadditions ◽  
Western Segment ◽  
Target Molecules

AbstractThe development of the intramolecular Diels–Alder cycloaddition­ of azole heterocycles, i.e. oxazoles (IMDAO), imidazoles (IMDAI), and thiazoles (IMDAT), has had a significant impact on the efficient preparation of heterocyclic intermediates and natural products. In particular, highly efficient and versatile IMDAO reactions have been utilized as a key step in several synthetic schemes to provide alkaloids and terpenoid target molecules. More limited studies have been performed on IMDAI and IMDAT cycloadditions. Some drawbacks, such as the occasionally­ challenging preparation of IMDA precursors, are also highlighted in this review. Perspectives are provided on how IMDAI and IMDAT­ transformations can be further expanded for target-directed syntheses.1 Introduction2 Oxazoles2.1 IMDAO Approaches to Furanosesquiterpenes and Furanosteroids2.1.1 Syntheses of Highly Oxygenated Sesquiterpenes2.1.2 Syntheses of (±)-Gnididione and (±)-Isognididione2.1.3 Synthesis of (±)-Stemoamide2.1.4 Synthesis of (±)-Paniculide A2.1.5 Syntheses of (+)- and (–)-Norsecurinine2.1.6 Synthesis of Evodone2.1.7 Syntheses of (±)-Ligularone and (±)-Petasalbine2.1.8 Syntheses of Imerubrine, Isoimerubrine, and Grandirubrine2.1.9 Syntheses of Furanosteroids2.1.10 Syntheses of Substituted Indolines and Tetrahydroquinolines2.2 IMDAO Approaches to Pyridines: the Kondrat’eva Reaction2.2.1 Syntheses of Suaveoline and Norsuaveoline2.2.2 Synthesis of Eupolauramine2.2.3 Syntheses of (–)-Plectrodorine and (+)-Oxerine2.2.4 Synthesis of Amphimedine2.2.5 Synthetic Approach to the Western Segment of Haplophytine2.2.6 Synthesis of Marinoquinoline A2.2.6.1 IMDAO Approach to Marinoquinoline A2.2.6.2 Scope of Allenyl IMDAO Cycloaddition2.3 Lewis Acid Catalysis in IMDAO Reactions2.3.1 Effects of Europium Catalysts on IMDAO Reactions2.3.2 Effects of Copper Catalysts on IMDAO Reactions3 Imidazoles 4 Thiazoles4.1 Syntheses of Menthane and Eremophilane4.2 Further Comments on the Intramolecular Cycloadditions of Thiocarbonyl Ylides5 Conclusions and Outlook

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

scholarly journals Bisoxazoline—Lewis Acid Catalyzed Direct-Electron Demand oxo-Hetero-Diels—Alder Reactions of N-Oxy-pyridine Aldehyde and Ketone Derivatives.

ChemInform ◽  
2007 ◽  
Vol 38 (19) ◽  
Author(s):  
Aitor Landa ◽  
Bo Richter ◽  
Rasmus Lyng Johansen ◽  
Anna Minkkilae ◽  
Karl Anker Joergensen
Keyword(s):  
Lewis Acid ◽  
Diels Alder ◽  
Acid Catalyzed ◽  
Electron Demand
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