[reaction: see text] The diastereoselective hetero-Diels-Alder reaction between Danishefsky's diene and chiral aldehydes is catalyzed by chiral chromium-Schiff base complexes. High levels of catalyst control are obtained in several cases, allowing access to all four stereoisomeric products through appropriate choice of aldehyde and catalyst enantiomers.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ol0258785 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Stereoselective synthesis of 6/7/6-fused heterocycles with multiple stereocenters an internal redox reaction/inverse electron-demand hetero-Diels-Alder reaction sequence.
Chem Commun (Camb)
June 2024
Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei, Tokyo 184-8588, Japan.
A highly stereoselective synthesis of fused heterocycles with multiple stereocenters an internal redox reaction/inverse electron-demand hetero-Diels-Alder (IEDHDA) reaction sequence is described. The present reaction sequence has three interesting features: (1) complete control of two potentially competitive processes, , hetero-Diels-Alder reaction and [1,5]-hydride shift; (2) one-shot construction of the complicated 6/7/6-fused heterocyclic structure having multiple stereocenters; and (3) high control of its stereoselectivity. When alkenylidene barbiturates with an allyl benzyl ether moiety were treated with a catalytic amount of Sc(OTf) and 2,2'-bipyridine, the internal redox reaction/IEDHDA reaction proceeded successively to afford 6/7/6-fused heterocycles in good chemical yields with good to excellent diastereoselectivities.
View Article and Find Full Text PDFIron-catalyzed asymmetric inverse-electron-demand hetero-Diels-Alder reaction of dioxopyrrolidines with simple olefins.
Chem Sci
March 2024
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 P. R. China
The asymmetric catalytic inverse-electron-demand hetero-Diels-Alder reaction of dioxopyrrolidines with a variety of simple olefins has been accomplished, significantly expanding the applicability of this cyclization to both cyclic hetero-dienes and dienophiles. A new type of strong Lewis acid catalyst of ferric salt enables the LUMO activation of dioxopyrrolidines formation of cationic species, this method yields a range of bicyclic dihydropyran derivatives with exceptional outcomes, including high yields (up to 99%), diastereoselectivity (up to 99 : 1) and enantioselectivity (up to 99% ee) under mild conditions. This facile protocol was available for the late-stage modification of several bioactive molecules and transformation into macrocycle molecules as well.
View Article and Find Full Text PDFIntramolecular Heteroatom and Styryl Diels-Alder Reactions, Asymmetric Cycloadditions of Chiral 3-Phenylallyl Maleic Esters.
J Org Chem
March 2024
Department of Chemistry and Biochemistry, Brigham Young University, C-100 BNSN, Provo, Utah 84602, United States.
Polycyclic aryl naphthalene and tetralin dihydro arylnaphthalene lactone lignans possess anticancer and antibiotic activity. Related furo[3,4-]pyranones, typified by the sequester-terpenoid isobolivianine, show similar antiproliferative bioactivity. Efficient syntheses of compounds featuring these polycyclic cores have proven challenging due to low yields and poor stereoselectivity.
View Article and Find Full Text PDFNickel-catalyzed asymmetric photoenolization/Mannich reaction of (2-alkylphenyl) ketones.
Chem Sci
July 2022
Key Laboratory of Green Chemistry & Technology, Ministry of Education, College of Chemistry, Sichuan University Chengdu 610064 China
A diastereo- and enantioselective photoenolization/Mannich (PEM) reaction of -alkyl aromatic ketones with benzosulfonimides was established by utilizing a chiral ,'-dioxide/Ni(OTf) complex as the Lewis acid catalyst. It afforded a series of benzosulfonamides and the corresponding ring-closure products, and a reversal of diastereoselectivity was observed through epimerization of the benzosulfonamide products under continuous irradiation. On the basis of the control experiments, the role of the additive LiNTf in achieving high stereoselectivity was elucidated.
View Article and Find Full Text PDFEnantioselective Organocopper-Catalyzed Hetero Diels-Alder Reaction through Oxidation of Ethers into Enol Ethers.
J Am Chem Soc
April 2022
Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02467, United States.
We disclose a catalytic method for the enantio- and diastereoselective union of alkyl ethers and heterodienes. We demonstrate that a chiral Cu-BOX complex catalyzes the efficient oxidation of ethers into enol ethers in the presence of trityl acetate. Then, the organocopper promotes stereoselective hetero Diels-Alder reaction between the generated enol ethers and β,γ-unsaturated ketoesters, allowing for rapid access to an array of dihydropyran derivatives possessing three vicinal stereogenic centers.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!