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 61 for “"cycloaddition reaction"”.
-
CRYSTAL ENGINEERING STUDIES ON THE MOLECULAR SALTS AND SILVER(I) COORDINATION COMPOUNDS FOR [2+2] CYCLOADDITION REACTION IN THE SOLID STATE
… analysed in terms of their solid state [2 + 2] cycloaddition reaction to synthesize a particular isomer of the corresponding cyclobutane compounds. The crucial role of the anions in the selective preorganization before photodimerization and the acid catalysed isomerisation of the cyclobutane …
-
Interfacial Nitrone 1,3-Dipolar Cycloadditions for Modification of Monolayer Protected Gold Nanoparticles
… and its ability to undergo the 1,3-dipolar cycloaddition reaction with a series of nitrones under ambient and high-pressure conditions. Expanding the scope of this reaction to the investigation in synthesizing a nitrone modified-MPN and examine its ability to undergo the 1,3-dipolar …
-
Enantioenriched Homoaldol Products, Beta-Substituted Ketones, Isoxazolines, and Beta-Lactams Through Elaboration of Allylamine Asymmetric Homoenolate Equivalents: Synthesis and Elucidation of Reaction Pathways
… intramolecular nitrone/olefin dipolar cycloaddition reaction of enantioenriched enals provides cyclopentyl isoxazoline products in 64--81% yields and with diastereomeric ratios of 78:22 to 84:16. An isoxazoline was converted into an enantiomerically pure beta-lactam via a beta-amino …
-
Synthesis of Aryl Ynol Ethers and Their Synthetic Applications
… of alkynes with a higher oxidation state in many reactions. However, few studies focused on the applications of aryl ynol ethers, because their synthetic methods are limited. To make aryl ynol ethers practical synthetic intermediates, we developed a direct and efficient method to synthesize aryl …
-
Preparation of benzoenyne -allenes, enyne -isocyanates and enyne -carbodiimides and their applications in the synthesis of polycyclic aromatic hydrocarbons and heterocycles
… the synthetic sequence and the mildness of the reaction condition make this pathway especially attractive. Interestingly, in certain cases the intramolecular [2+2] cycloaddition reaction of the chlorinated benzoenyne-allene intermediates occurred preferentially to form 1H-cyclobut[a]indenes. …
-
Efforts Toward the Total Synthesis of Asparagamine A
… an intramolecular azomethine ylide 1,3-dipolar cycloaddition reaction as the key step. Generation of the azomethine ylide species is achieved via sequential vinylogous amide O-sulfonylation and desilylation. Several strategies designed to construct the fully oxygenated aza-tricyclo[5.3.0.0 …
-
Tandem Cycloaddition Chemistry: Part I. Synthesis and Crystallographic Analysis of 1-Azafenestranes. Part II. Synthesis and Reactivity of N-Vinyl Nitrones
Tandem cycloaddition chemistry has been explored with regard to the synthesis and crystallographic analysis of molecules of theoretical interest, the 1-azafenestranes, and the development of a new type of heterodiene, the N-vinyl nitrone. The tandem [4+2]/[3+2] cycloaddition of a nitrocyclopentene …
-
Chemoselective and Stereoselective Exploration of the Chemical Reactivity Space of Castagnoli-Cushman-Derived Allylic Lactamoyl Esters: Application to the Synthesis of Aza-Polycyclic Architectures
… outcomes are achieved through a novel [4 + 2] cycloaddition reaction between an <em>N</em>-iodoarylated-1,3-azadiene and cyclic anhydrides, followed by interception of the cycloadducts in cross-coupling manifolds (<em>e.g.</em>, Sonogashira coupling) and concomitant lithiation-cyclization of …
-
Explorations of Intramolecular [5+2] Cycloadditions of Ring-Constrained Vinylcyclopropanes
The first example of a [5+2] cycloaddition reaction wherein the olefin of the vinylcyclopropyl moiety is constrained in a carbocycle was explored, and possible reasons on the lack of reactivity of the substrate were studied. A simple model substrate was synthesized and subjected to cycloaddition …
-
The Triplex Diels-Alder Reaction: An Investigation of Enantioselectivity and Scope
Part I. Enantioselective triplex Diels-Alder reaction. An investigation of the enantioselective triplex Diels-Alder reaction has been performed with optically active biaryl sensitizers, (-)1,1$\sp\prime$bis(2,4-dicyanonaphthalene) and (-)1,1$\sp\prime$bis(2,10-dicyanoanthracene). Irradiation of an …
-
An Investigation of Gold(I) Catalyzed Cycloaddition Reactions
… the furan moiety to give transannular [4C+3C] cycloaddition products. In addition, the tricyclic ring system with an oxabicyclo-[3.2.1]octadiene and a fused 6-membered ring was produced efficiently using the readily available propargyl ester-furan substrate in the presence of a Au(I) complex. …
-
Novel tricycloundecane derivatives as potential N-methyl-Daspartate receptor and calcium channel inhibitors for neuroprotection
… to inhibit NMDA receptors and VGCC. The cycloaddition reaction between p-benzoquinone and monomerised dicyclopentadiene yielded tricycloundeca- 4,9-diene-3,6-dione which was used as the base structure and further derivatised. These derivatives were conjugated with benzylamine to form a …
-
Transition Metal-Mediated Higher-Order Cycloaddition Reactions: Application To The Total Synthesis Of Complex Natural Products
… <p>TRANSITION METAL-MEDIATED HIGHER-ORDER CYCLOADDITION REACTIONS: APPLICATION TO THE TOTAL SYNTHESIS OF COMPLEX NATURAL PRODUCTS</p> <p>by</p> <p>BILAL ABOU ALEIWI</p> <p>October 2010</p> <p>Advisor: Dr. James H. Rigby</p> <p>Major: Chemistry (Organic)</p> <p>Degree: Doctor of …
-
Bromonium-Initiated Epoxide-Opening Cascades : total Synthesis of ent-Dioxepandehydrothyrsiferol and Synthetic Studies toward (+)-Scholarisine A
… of exogenous trapping nucleophiles into the reaction. [chemical formulae] CHAPTER 11. Synthetic Studies toward (+)-Scholarisine A. A concise and scalable route toward the monoterpene indole alkaloid (+)- scholarisine A has been developed. Synthetic highlights of the route include: 1) …
-
Gold-catalyzed synthesis and functionalization of heteroarenes
… of gold-catalyzed synthesis or functionalization reactions or heteroarenes. The work is presented in four different chapters. The first chapter summarizes the most representative reactivity trends in the field of gold catalysis and serves as general introduction. The second chapter is focused on …
-
Singlet Oxygen Generation Via Irradiation of 4-Benzylamino-7-Nitrobenz-2-Oxa-1, 3-Diazole
… with 1, 3-cyclohexadiene (CHD) as acceptor. A reaction between BBD and the acceptor rendered this method of singlet oxygen detection useless. In a second approach, the rate of light-induced oxygen consumption for solutions having various components was measured. The results showed that for a …
-
1. Chromium(0)- Promoted Higher Order Cycloaddition Reactions: Studies Toward The Total Synthesis Of The Cyclocitrinols And Echinopines A And B 2. Total Synthesis Of (±)-Debromoflustramine B Via [4+1] Cyclization Of An Indole Isocyanate And A Bis(alkylthio)carbene
… Cr(0)-promoted [6π + 4π] photochemical cycloaddition reaction.</p> <p>A Bronsted acid catalyzed rearrangement of the 11-trimethylsilyl-tetracyclo[8.1.0.03,7.04,11]undeca-5,8-diene ring system to the unusual homotriquinacene ring system. The trimethylsilyl substitution on the cyclopropane …
-
The Design and Synthesis of Novel Chiral Z-Nitrones with Applications Towards the Syntheses of Enantiomerically Pure 4-Hydroxy Amino Acids
… acids have been synthesized via 1,3-dipolar cycloadditions of novel Z-nitrones and substituted olefins. Three achiral nitrones were synthesized in pursuit of a conformationally stable yet reactive Z-nitrone. The carboisopropoxynitrone was determined to be the best synthon in cycloadditions …
-
Biomimetic synthesis of meroterpenoid natural products using dearomatization strategies
… was an oxidative radical cyclization cascade reaction, where four new carbon-carbon bonds, four new carbocyclic rings and five new stereocentres were formed in the one step. The first total synthesis of merochlorin A was achieved in five linear steps from methyl-3,5- dimethoxyphenylacetate (6% …
-
Conjugation of oligonucleotides for drug delivery via a linker derived from Meldrum’s acid and A capture-release method to synthesize long oligonucleotides
… for linking modular units via simple chemical reactions under mild conditions, often in benign solvents. Our research explores the conjugation of biomolecules using Meldrum’s acid derivatives as linkers, facilitating the stepwise attachment of an amine and a thiol under mild and neutral aqueous …
Page 1 of 4