Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 22 for “"dearomatization"”.
-
Biomimetic synthesis of meroterpenoid natural products using dearomatization strategies
… + 2] cycloaddition reaction induced be oxidative dearomatization to form the bicyclo[3.2.1]octane core. The first total synthesis of the napyradiomycin natural product naphthomevalin was achieved in 11 steps from methyl-3,5-dimethoxyphenylacetate (1.4% overall yield). The key biomimetic synthetic …
-
New Methods for Palladium-catalyzed Decarboxylative Benzylation, Arylation and Dearomatization Reactions
… the unprecedented catalytic decarboxylative dearomatization and arylation reactions of ketone enolates. Two sets of protocols involving simple variation of ligands were then developed for the selective decarboxylative dearomatization or arylation of enolates. These methods provided alicyclic …
-
Unique applications of dearomative strategies: I) arene-oxides/oxepines through a dearomative epoxidation of non-activated arenes Ii) arenophile-mediated dearomatization of pyridines Iii) solution-state electrochemical dearomatization of polystyrene
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2025-08-01
-
A Modular Approach to Highly Functionalized Indole Derivatives and Syntheses of Tryptamine-based SHIP Inhibitors
… of densely functionalized tryptamines.</p> <p>Dearomatization reaction is a powerful tool that converts planar aromatic compounds into interesting highly functionalized three-dimensional structures. The reactions discussed herein include the alkylative dearomatization through activation of …
-
Synthetic Studies of the Yunnaneic Acids
… synthesized in a single step via a oxidative dearomatization/Diels-Alder cascade sequence from simple precursors. Dimerization studies towards yunnaneic acid A and yunnaneic acid B are also described, which resulted in the synthesis of several novel, non-natural structures.
-
Dearomative functionalization of simple arenes: Reduction and palladium-catalyzed syn-1,4-aminofunctionalizations
… features of these processes compared to existing dearomatization reactions are: 1) amenable aromatic substrates encompassing a wide range of non-activated arenes as well as heteroarenes, 2) selective installation of functional groups to the dearomatized arene occurs in a single pot, 3) broad …
-
Synthetic Efforts Toward Hypoestoxide, Platensimycin, And Guttiferone G
… access the oxa-bicyclic moiety and an alkylative dearomatization to complete the carbocyclic core. Guttiferone G belongs to the family of [3.3.1] bicyclic polyprenylated phloroglucinol derived natural products, which have been isolated from various plant species found primarily in the tropical or …
-
Dearomative reduction of arenes through the use of arenophiles & studies towards the synthesis of cardiotonic steroids calotropin and calactin
… condensation, and Pd-catalyzed nucleophilic dearomatization of a phenol is described. Also described, is the semisynthetic strategy towards calotropin from estrone, where the aromatic A ring is dearomatized to introduce a C1 fragment at the para-position.
-
Dearomative transformations in synthesis: I. Dearomative dihydroxylation with arenophiles II. Total synthesis of lycoricidine and narciclasine III. Towards the total synthesis of collybolide
Dearomatization reactions represent a powerful tool for the conversion of readily-available arenes into structurally complex, high-value intermediates in synthesis. Although there are many classic and modern approaches for overcoming the resonance stability inherent in these compounds, the …
-
Stereoselective Heterocycle Synthesis via Alkene Difunctionalization: Bulky Phosphine Ligands Enable Pd-Catalyzed Arylhalogenation, Arylcyanation and Diarylation
… Chapter 3 discusses the extention of the indole dearomatization methodology wherein both a dearomative syn 1,2-diarylation and a syn 1,2-arylvinylation were achieved. This methodology utilizes readily available aryl and vinyl boroxines as coupling partners, and exhibits an extremely large …
-
New reactivity and selectivity in transition metal-catalyzed C-C and C-N bond forming processes
… derivatives. A copper-catalyzed cyanative dearomatization mechanism is proposed to account for the regiochemical course of this reaction. This mechanism has been validated through density functional theory calculations. Computational studies revealed that the high level of ortho selectivity …
-
Aromaticity Across States: A Framework for Reactivity and Structure in Organic Systems
… Computed reaction profiles show that dearomatization is required for arenes to exhibit ene- and diene-like reactivity. While substituted and η6-coordinated arenes retain high free energy barriers, strongly dearomatized η2- and η4-arenes display substantially lower barriers (~20 kcal …
-
The Pd-catalyzed fluorination of (hetero)aryl bromides and triflates
… fluorides from L-Pd(Ar)F species. An unexpected dearomatization/arylation process of Pd(II) complexes bearing bulky biaryl phosphines was discovered, resulting in ligand arylation during the catalytic fluorination of aryl triflates. This process must occur prior to C-F reductive elimination. …
-
Anion Relay Cyclopropanation and Aryl Vinyl Cyclopropane Cope Rearrangements
… of the cyclopropane strain release to drive dearomatization. The reaction described in this document features a dynamic equilibrium of aryl vinyl cyclopropane diastereomers prior to Cope rearrangement, allowing the difficult Cope rearrangement to be accomplished even without stereodefined …
-
Development of New Organic Photoredox Catalysis Driven by Visible Light
… high deuteration level (>90%). The direct dearomatization of indoles represents the most straightforward access to indolines. However, the exiting dearomative methods largely restrict to electron-rich indoles or go through an ionic process using strong nucleophiles. Toward this end, an …
-
Total synthesis enabled by nickel-catalyzed transformations: Dearomative carboamination and methylenecyclopropane annulation
… Chapter 2 describes our efforts to develop this dearomatization reaction, and the subsequent investigations of the synthetic utility of our newly formed diene product to access the cyclitol core. Upon the completion of the synthesis of the 7-deoxypancratistatin and pancratistatin, we then …
-
Methodology and total synthesis enabled by cycloadditions
Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2023-09-01 without embargo terms
-
Arenophile-mediated dearomative functionalization of unactivated arenes
Two photomediated dearomative methods are reported using an “arenophile” called MTAD. Arene-arenophile cycloadducts are formed by irradiation of mixtures of unactivated arenes and MTAD at cryogenic temperatures with visible light. These cycloadducts are subsequently used as substrates in …
-
Dearomative hydroboration-enabled synthesis of idarubicinone and synthesis of minor cannabinoids and their metabolites
Anthracyclines are archetypal representatives of tetracyclic type II polyketide natural products that are widely used in cancer chemotherapy. Although syntheses of this class of compounds have been extensively explored, all known approaches are based on annulations, relying on the union of properly …
-
The development of dearomative functionalizations and their use in the total synthesis of bioactive natural products
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2024-05-01
Page 1 of 2