()-2,15-Cl-DHTP-boron complex catalyst for the asymmetric Diels-Alder cycloaddition of 2'-hydroxychalcones and dienes was developed and tested. The resulting cyclohexenes with three chiral centers were obtained in high yields (up to 98%) with excellent stereoselectivities (up to >20:1 /, >99% ee). This catalytic system features high efficiency, broad substrate scopes, and mild reaction conditions. In addition, a DFT study was performed to explain the stereochemical course of the asymmetric induction.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.orglett.0c02978 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines.
Beilstein J Org Chem
December 2024
Departamento de Química Orgánica y Química Inorgánica, Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá (IRYCIS), 28805 Madrid, Spain.
Asymmetric cycloaddition is a straightforward strategy which enables the synthesis of structurally distinct cyclic derivatives which are difficult to access by other methodologies, using an efficient and atom-economical path from simple precursors. In recent years several asymmetric catalytic cyclization strategies have been accomplished for the construction of -heterocycles using various catalytic systems such as chiral metal catalysts, chiral Lewis acids or chiral organocatalysts. This review presents an overview of the recent advances in enantioselective cyclization reactions of 1-azadienes catalyzed by non-covalent organocatalysts.
View Article and Find Full Text PDFEnantioselective Cycloaddition of Formed aza-Dienes and Vinyl Diazo Compounds for the Synthesis of Optically Enriched and Diazo Containing Tetrahydropyridazine.
J Org Chem
December 2024
Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637002, China.
A copper catalyzed enantioselective formal aza-Diels-Alder reaction of formed 1,2-diaza-1,3-dienes from α-halohydrazones and vinyl diazo compounds was described. The protocol provides a variety of optically enriched diazo-containing tetrahydropyridazines in moderate yields and with up to excellent enantioselectivities. The present methodologies utilize chiral oxazolines as the chiral ligands for asymmetric catalysis and feature mild reaction conditions, readily available substrates, and broad substrate scope.
View Article and Find Full Text PDFMetal Ion-Mediated Supramolecular Nanotube Catalyst for Enantioselective Reactions.
Langmuir
December 2024
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, China.
Rational control over the morphologies of supramolecular assemblies for asymmetric catalysis with enhanced enantioselectivity represents a pivotal challenge in the realm of synthetic chemistry and material technology. Herein, Cu(II) ion-mediated supramolecular nanostructures assembled from chiral amino acid-based amphiphiles (l/d-AlaC) are fabricated as chiral catalysts for Diels-Alder cycloaddition between aza-chalcone and cyclopentadiene. In particular, compared with the supramolecular nanosheet formed by l/d-AlaC without Cu(II) ions, we found that the l/d-alanine chiral amphiphile can form supramolecular nanotubes with a multilayer structure and with the thickness of the tubular wall about 15 nm through the transition from a nanoribbon to tubular structure in the presence of Cu(II) ions.
View Article and Find Full Text PDFCatalytic Asymmetric Cycloaddition of Olefins with In Situ Generated -Boc-Formaldimine.
J Am Chem Soc
November 2024
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim an der Ruhr, Germany.
Chiral 1,3-amino alcohols are ubiquitous structural motifs in natural products and active pharmaceutical ingredients. We present a highly enantioselective, inverse-electron-demand hetero-Diels-Alder reaction of olefins with in situ generated -Boc-formaldimine catalyzed by strong and confined Bro̷nsted acids. This transformation provides direct access to valuable 1,3-amino alcohols from styrenes and 1,1-disubtituted alkenes.
View Article and Find Full Text PDFAsymmetric Organocatalytic Diels-Alder Reaction of Olefinic Azlactones with Unsaturated Thiazolones: Access to Spirocyclohexenone Thiazolone Skeletons.
J Org Chem
October 2024
Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh 208016, India.
Chiral bifunctional thiourea-catalyzed Diels-Alder reaction between olefinic azlactones and alkylidene thiazolone derivatives is reported here for the first time. The asymmetric Diels-Alder reaction delivers vicinal tertiary-quaternary stereocenters in spirocyclohexenone thiazolones in moderate to high yields and good stereochemical outcomes. The protocol can be adapted to a broad array of substrates.
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!