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Full-Text Articles in Organic Chemistry

Higher Energy Gap Control Of Fluorescence In Conjugated Polymers, Chien-Hung Chiang Mar 2018

Higher Energy Gap Control Of Fluorescence In Conjugated Polymers, Chien-Hung Chiang

LSU Doctoral Dissertations

Chemo- and biosensors based on fluorescent conjugated polymer benefit from greater detection sensitivity due to amplification of the electronic perturbations produced by analyte binding. This amplification stems from the exciton-transporting properties of conjugated polymers. A conventional design paradigm relies on the analyte binding events which generate sites of lower energy relative to the polymer energy: either fluorescence quenching sites (turn-off sensors) or bathochromically shifted fluorophores (turn-on sensors). In both type sensors, the excitons migrate to the lower-energy site created by analyte binding.

This dissertation primarily focused the investigation of an alternative paradigm when analyte binding creates higher energy gap sites ...


Impact Of Chemical Doping On The Thermoelectric Charge Transport Of Organic Semiconductors, Connor J. Boyle Jan 2018

Impact Of Chemical Doping On The Thermoelectric Charge Transport Of Organic Semiconductors, Connor J. Boyle

Doctoral Dissertations

The thermoelectric properties of organic semiconductors allow them to directly convert heat into electricity without the use of moving parts and to directly convert electricity into heat without the use of working fluids. These properties offer opportunities for the generation of electricity from non-conventional or renewable sources of heat and for refrigeration without the risk of leaking harmful working fluids at any length scale down to the nanoscale. Since organic materials are lightweight, flexible, and made from abundant resources, these opportunities could one day become affordable for widespread use and could be expanded to include specialized and otherwise difficult to ...


Thermal, Mechanical, And Conductive Properties Of Bisimidazolium Thiol-Ene Pil Networks, Sunny Kwan, Sunny Kwan Sep 2017

Thermal, Mechanical, And Conductive Properties Of Bisimidazolium Thiol-Ene Pil Networks, Sunny Kwan, Sunny Kwan

Honors College Theses

Polymers made from thiol-ene reactions are versatile – they can be made from a variety of easily obtainable starting materials and show promise as biomedical materials, hydrogels, resins, and nanoparticles. Ionic liquids (ILs) have uniquely exploitable physical and chemical properties, and polymerization of ILs into polymeric ionic liquids (PILs) enhances or changes these properties, allowing an even wider range of potential applications of ILs in technologies such as fuel cells, solar cells, and even artificial muscles. Bisimidazolium thiol-ene PIL (BITPIL) networks are polymers with each monomer consisting of two moles of bis-imidazolium bridged together with either an alkyl or poly(ethylene ...


Reducing Dynamic Disorder In Small-Molecule Organic Semiconductors By Suppressing Large-Amplitude Thermal Motions, Steffen Illig, Alexander S. Eggeman, Alessandro Troisi, Lang Jiang, Chris Warwick, Mark Nikolka, Guillaume Schweicher, Stephen G. Yeates, Yves Henri Geerts, John E. Anthony, Henning Sirringhaus Feb 2016

Reducing Dynamic Disorder In Small-Molecule Organic Semiconductors By Suppressing Large-Amplitude Thermal Motions, Steffen Illig, Alexander S. Eggeman, Alessandro Troisi, Lang Jiang, Chris Warwick, Mark Nikolka, Guillaume Schweicher, Stephen G. Yeates, Yves Henri Geerts, John E. Anthony, Henning Sirringhaus

Chemistry Faculty Publications

Thermal vibrations and the dynamic disorder they create can detrimentally affect the transport properties of van der Waals bonded molecular semiconductors. The low-energy nature of these vibrations makes it difficult to access them experimentally, which is why we still lack clear molecular design rules to control and reduce dynamic disorder. In this study we discuss the promising organic semiconductors rubrene, 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothio-phene and 2,9-di-decyl-dinaphtho-[2,3-b:20,30-f]-thieno-[3,2-b]-thiophene in terms of an exceptionally low degree of dynamic disorder. In particular, we analyse diffuse scattering in transmission electron microscopy, to ...


Synthesis And Characterization Of Neo-Confused Porphyrins And Related Systems, Arwa Salem Almejbel Nov 2015

Synthesis And Characterization Of Neo-Confused Porphyrins And Related Systems, Arwa Salem Almejbel

Theses and Dissertations

Carbaporphyrins have been the focus of many studies, and a wide variety of related carbaporphyrinoid systems have been reported. N-confused porphyrins are a class of carbaporphyrins where one pyrrole unit has been inverted. In this work, a newly discovered family of porphyrin isomers where one of the pyrrolic subunits is connected to the meso-bridges in a 1,3-fashion, called neo-confused porphyrins, has been investigated.

Reaction of pyrrole-3-carbaldehydes with acetoxymethylpyrroles and NaH in DMF gave neo-confused dipyrrylmethane dialdehydes. The resulting dialdehydes underwent an acid catalyzed condensation with a dipyrrylmethane to give neo-confused phlorins, and following oxidation with FeCl3 afforded new neo-confused ...


Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles May 2015

Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles

University Scholar Projects

Central to the advancement of small molecule synthesis is the ability to develop methodologies that reimagine well known chemistry in a new, environmentally friendly manner. In this thesis two central themes emerge: oxoammonium salt oxidations and trifluoromethyl incorporation using fluoroform gas. Several projects have been developed surrounding oxoammonium salt chemistry, which are featured by their mild conditions, ease of use, and the metal-free, recyclable nature of the oxidant. Trifluoromethylation using fluoroform gas finds its utility in the use of a potent greenhouse gas waste product as a benchtop reagent.


Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles May 2015

Methodology Development In Green Chemistry: Oxoammonium Salt Oxidations And Fluoroform Incorporation, Rebecca J. Wiles

Honors Scholar Theses

Central to the advancement of small molecule synthesis is the ability to develop methodologies that reimagine well known chemistry in a new, environmentally friendly manner. In this thesis two central themes emerge: oxoammonium salt oxidations and trifluoromethyl incorporation using fluoroform gas. Several projects have been developed surrounding oxoammonium salt chemistry, which are featured by their mild conditions, ease of use, and the metal-free, recyclable nature of the oxidant. Trifluoromethylation using fluoroform gas finds its utility in the use of a potent greenhouse gas waste product as a benchtop reagent.


Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk Jan 2015

Photogenerated O-Azaxylylenes: Mechanistic Studies And Synthetic Applications, William Cole Cronk

Electronic Theses and Dissertations

This research sets out to build upon excited state o-azaxylylene cycloaddition. The mechanism behind the excitation and cycloaddition process of photogenerated o-azaxylylenes was determined experimentally. Time-correlated single-photon counting, steady-state spectroscopy, triplet quenching experiments, and quantum yield studies provided evidence suggesting that excited state intramolecular proton transfer is followed by intersystem crossing and stepwise addition to the tethered unsaturated pendant.

In keeping with the principles of diversity oriented synthesis, a modular approach was taken to gain access to a diverse array of N,O,S-Polyheterocycles which were modified postphotochemically via Suzuki coupling to yield fused biaryls. Cycloaddition products, outfitted ...


Ozonolysis Of Silyl Enol Ethers: Synthesis Of 3-Silyloxy-1,2-And 3-Alkyl-3-Silyloxy-1,2-Dioxolanes, Katrina Wilson Jan 2015

Ozonolysis Of Silyl Enol Ethers: Synthesis Of 3-Silyloxy-1,2-And 3-Alkyl-3-Silyloxy-1,2-Dioxolanes, Katrina Wilson

Undergraduate Honors Theses

Silyl enol ethers are important synthetic intermediates that are used in a variety of reactions. The ozonolysis of silyl enol ethers to anomalous 1,2-dioxolane products has not yet been fully been explored. Though the synthesis of silyl enol ethers from aldehydes, ketones, and esters is relatively straightforward, the most commonly used methods still require air- or moisture-sensitive conditions and/or the use of toxic solvents. We have shown that silyl enol ethers can be easily synthesized from aldehydes and ketones under mild conditions and with a straightforward workup procedure in good to excellent yields. We ozonolyzed these silyl enol ...


The Synthesis Of A Bisbenzothiophene (Bbt) Based Organic Semiconductor With Increased Function And Increased Solubility, Mary England Jan 2014

The Synthesis Of A Bisbenzothiophene (Bbt) Based Organic Semiconductor With Increased Function And Increased Solubility, Mary England

Senior Honors Theses

Organic semiconductors are growing in applications for use in modern technology.1 The main interest in these molecules can be attributed to their low cost (compared to silicon) and their ability to be used on flexible substrates. There are four features that make a good organic semiconductor. First, the molecule should be conjugated, having alternating single and double bonds (lone electron pairs act similarly to double bonds). Secondly, the molecule should be planar, or flat, in shape. Thirdly, the molecule should have a narrow band gap to increase the overall conductivity. Lastly, the molecule should be soluble to ease application ...


Studies Of Solution-Processed Organic Light-Emitting Diodes And Their Materials, Emily Hellerich Jan 2013

Studies Of Solution-Processed Organic Light-Emitting Diodes And Their Materials, Emily Hellerich

Graduate Theses and Dissertations

The wide use of organic light-emitting diodes (OLEDs) is materializing as devices exhibit enhanced performance. Attention has been placed on finding quality solution-processable organic semiconducting materials amenable to low cost processing via solution-based fabrication methods. The high solubility and good film formability intrinsic to polymers have led to their use in the majority of solution-processed devices. Recently, attention has shifted to the incorporation of small molecules into solution-processed devices. With this focus, we gain the high efficiency of small molecules as well as the ease of fabrication by solution-processing. Research has also been aimed at developing materials with efficient and ...


Synthesis, Evaluation And Applications Of Biologically Significant Molecules And Their Analogues, Sneha Ashesh Belapure Dec 2012

Synthesis, Evaluation And Applications Of Biologically Significant Molecules And Their Analogues, Sneha Ashesh Belapure

Doctoral Dissertations

Synthetic chemists are always looking for challenging problems to solve. Design and synthesis of novel molecules that can act as agents of chemical and biological modification are one of the foremost goals of a synthetic chemist. This dissertation describes advances and efforts made in this area.

Obesity is one of the critical problems of the modern age. Molecules that can remediate this condition are highly sought after. The first chapter of this dissertation describes synthetic strategies explored to prepare these valuable natural products along with their structural and stereochemical analogues to study structure and activity relationships (SAR). This method gives ...


Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay Aug 2012

Studies Toward The Total Synthesis Of Antascomicin B, David Ross Clay

Theses and Dissertations

The following dissertation describes synthetic efforts toward the synthesis of the C21-C34 fragment of antascomicin B. Our initial enzymatic approach is detailed as well as an asymmetric transfer hydrogenation (ATH) strategy that will be used in the eventual total synthesis of the molecule. Several investigations into anomalies observed during (ATH) reactions are also discussed.


Synthetic Approaches To Natural Products , John Herman Malpert Jan 1997

Synthetic Approaches To Natural Products , John Herman Malpert

Retrospective Theses and Dissertations

The total synthesis of natural products and their analogs is a very exciting and challenging area of organic chemistry. The biological activities of these natural products make this area of chemistry popular. Our synthetic approaches towards the biologically active molecules eburnamonine, MS-444, halenaquinone and their analogs represent a valuable contribution to the field of organic chemistry;We have devised a synthetic pathway that completes four of the five rings of eburnamonine. In addition this pathway can be used to synthesize a variety of indolo(2,3-a) quinolizines, demonstrating the wide versatility of our pathway;We have also devised a synthetic ...


Design, Synthesis, Characterization And Study Of Novel Conjugated Polymers , Wu Chen Jan 1997

Design, Synthesis, Characterization And Study Of Novel Conjugated Polymers , Wu Chen

Retrospective Theses and Dissertations

A series of conjugated polymers was designed and synthesized. The chemical structures of the polymers were characterized by 1H- and 13C-NMR, and the molecular weights were measured by GPC. Their thermal behaviors were studied by DSC and TGA. Their UV/Vis absorption, fluorescence and conductivity were also studied. The copolymers having repeating units with combinations of poly(phenylenevinylene) (PPV), poly(phenyleneethynylene) (PPE) and poly(paraphenylene) (PPP) were usually strongly luminescent. The poly(phenylenevinylene) and poly(phenyleneethynylene) copolymer-based LED device showed symmetric I-V curve, which was quite different from non-symmetric curves reported for PPV-based or PPE-based LEDs. The values of the ...


Photostimulated Tert-Butylations Of A,B-Unsaturated Nitriles, Cyclizations Of 1,6-Dienes And Olefinic Nitriles, And Homolytic Aromatic Alkylations , Ping Chen Jan 1997

Photostimulated Tert-Butylations Of A,B-Unsaturated Nitriles, Cyclizations Of 1,6-Dienes And Olefinic Nitriles, And Homolytic Aromatic Alkylations , Ping Chen

Retrospective Theses and Dissertations

[alpha],[beta]-Unsaturated nitriles undergo radical chain addition reactions with tert-butylmercury halides in the presence of iodide ions. The mercury adduct products are formed in high yields and can be converted to the reductive alkylation products with NH4+ or by NaBH4. The addition reaction involves the attack of the adduct radical upon the ate complex, t-BuHgI2-. Proton donors also promote the reactions by protonating the adduct radicals to form keteniminyl radicals cations which accept an electron from t-BuHgI2- to produce the alkylation products. Acrylonitrile, crotononitrile and fumaronitrile give nearly quantitative yields of the products in DMSO via photolysis or even ...


Palladium(Ii)-Catalyzed Organic Transformations Employing Oxygen Gas As The Stoichiometric Reoxidant , Karl Patrick Peterson Jan 1997

Palladium(Ii)-Catalyzed Organic Transformations Employing Oxygen Gas As The Stoichiometric Reoxidant , Karl Patrick Peterson

Retrospective Theses and Dissertations

The organic transformations promoted by palladium(II) species have historically required either stoichiometric amounts of metal or the stoichiometric use of a chemical reoxidant, such as benzoquinone or Cu(II) salts. In recent years, several reports have described the use of oxygen gas as the stoichiometric reoxidant in Pd(II) chemistry. This advance has made the chemistry of Pd(II) more attractive because of reductions in cost and waste generation. This development has also encouraged researchers to probe the scope and limitation of Pd(II) chemistry using oxygen gas as the sole reoxidant of the metal. Three such organic transformations ...


Study On The Photolysis And Thermolysis Of Alkyl Aryl Sulfoxides , Yushen Guo Jan 1997

Study On The Photolysis And Thermolysis Of Alkyl Aryl Sulfoxides , Yushen Guo

Retrospective Theses and Dissertations

After a brief deliberation of the research objective and justification, Chapter 1 is a general literature review of sulfoxide photochemistry. The following four chapters focus on photolysis and thermolysis studies of acyclic sulfoxides employing various structures;The photochemistry of aryl benzyl sulfoxides has been studied in extensive detail as a prototype of [alpha]-cleavage. The initial event is homolytic cleavage to form a singlet arylsulfinyl/benzyl radical pair which partitions between reversion to starting material with at least partial racemization and closure to form a sulfenic ester. This is the first well characterized sulfenic ester intermediate from the photolysis of ...


Cooperative Binding By A Self-Assembled Receptor: Metal In A Structural And Functional Role , Jin-Ho Lee Jan 1994

Cooperative Binding By A Self-Assembled Receptor: Metal In A Structural And Functional Role , Jin-Ho Lee

Retrospective Theses and Dissertations

Metal complexes of the amino acid, 4,4[superscript]'-phosphinylidine bis phenylalanine (PBP*, 1), self-assemble to produce a macrocyclic receptor (Co[subscript]2PBP[subscript]2, 2) with a hydrophobic cavity capable of binding aromatic compounds from water. Here we demonstrate that the metal can play a structural and a functional role: the receptor binds substrates bearing both aromatic and polar functional groups ditopically, using the hydrophobic pocket as well as the metal itself. The doubly anionic Co[superscript]2+ macrocyclic complex binds neutral aromatic guests more tightly than it does most anionic guests, as would be expected. However, carboxylates tethered ...


Syntheses And Studies Of Acetylenic Polymers , Yiwei Ding Jan 1994

Syntheses And Studies Of Acetylenic Polymers , Yiwei Ding

Retrospective Theses and Dissertations

A series of new diiodo aryl compounds have been conveniently synthesized. Based on these diiodo compounds, a series of novel soluble polymers, poly(2,5-dialkoxy-1,4-phenyleneethynylene)s (PPE polymers) have been synthesized by using a palladium-catalyzed polymerization. These PPE polymers have been well characterized by routine methods. The molecular weights range from 8,000 to 40,000;The properties of these PPE polymers such as absorption, fluorescence, and conductivity have been studied. A PPE polymer with the butoxy side chain exhibits a weak electrical conductivity ([sigma] = 10[superscript]-3 S/cm) after doping with AsF[subscript]5. The absorption spectra ...


Synthetic Approaches To Huperzine A , Danette René Vines Jan 1994

Synthetic Approaches To Huperzine A , Danette René Vines

Retrospective Theses and Dissertations

The natural product huperzine A has been found to possess activity as a nootropic agent. Because of its memory facilitating effects, huperzine A represents a promising drug for the treatment of neurodegenerative diseases, such as Alzheimer's disease. As life expectancy increases, identifying and synthesizing drugs which treat cognitive dysfunction becomes a primary health objective;This study was undertaken to synthesize huperzine A, and to offer a direct route to improved analogs of huperzine A. A bicyclic amino ketone for the synthesis of huperzine A was prepared in six steps. The conjugate addition of metallated alkylpyridines afforded a direct route ...


Total Synthesis Of Pyranonaphthoquinone Natural Products , Jun Li Jan 1994

Total Synthesis Of Pyranonaphthoquinone Natural Products , Jun Li

Retrospective Theses and Dissertations

Pyranonaphthoquinones are a class of naturally occurring antibiotics which have in common a synthetically interesting isochromanquinone skeleton. Members of this family exhibit a variety of biological activities. Examples are frenolicin B, an anticoccidial agent; kalafungin, an antifungal agent; hongconin, having cardioprotective activity against angina pectoris. Efforts toward the direct synthesis of these natural pyranonaphthoquinones forced us to develop new methodologies. During our research, a general methodology was developed to stereoselectively synthesize the common isochromanquinone skeleton. The key step in the syntheses, a regioselective Diels-Alder reaction, proceeds with complete regiocontrol and in excellent yield. This work has led to extremely direct ...


Mechanistic Study Of The Thermal Rearrangement Of Silylheterocumulenes And Their Propargyl Isomers , Glenn Robert Magrum Jan 1989

Mechanistic Study Of The Thermal Rearrangement Of Silylheterocumulenes And Their Propargyl Isomers , Glenn Robert Magrum

Retrospective Theses and Dissertations

The formation of bis(silyl)ketenes on reaction of 2,3-dihydrofuran (and 2,3-dihydro-2-phenylfuran) with n-BuLi and quenching with chlorosilanes was investigated and found to occur by the rearrangement of siloxyacetylene intermediates. 2,3-Dihydro-thiophene did not undergo similar decomposition;4,5-Dihydro-3-methyl-2-(trimethylsilyl)furan and 2,3-dihydro-5-(trimethylsilyl)thiophene were both subjected to flash vacuum pyrolysis (FVP) and found to undergo reductive elimination to form vinylidenes, which then formed the corresponding acetylenes. When 2,3-dihydro-2-phenyl-5-(trimethylsilyl)furan was subjected to FVP only fragmentation occurred. These results were suggestive of a concerted mechanism, versus a homolysis mechanism, for the formation of silylketenes ...


Synthesis Of Heterocycles Via Palladium-Catalyzed Heteroannulation Of Dienes , Norman Graciano Berríos-Peña Jan 1989

Synthesis Of Heterocycles Via Palladium-Catalyzed Heteroannulation Of Dienes , Norman Graciano Berríos-Peña

Retrospective Theses and Dissertations

Organopalladium chemistry has evolved as a powerful technique in organic synthesis. The ever coming new developments in this chemistry inspired us to develop a new synthetic approach towards the synthesis of heterocycles. In this dissertation, the syntheses of a variety of nitrogen- and oxygen-containing heterocycles were accomplished from the reactions of functionalized aryl iodides with 1,2-, 1,3-, and 1,4-dienes in the presence of catalytic amounts of palladium. It was shown that benzofuran, dibenzofuran, benzopyran, dibenzopyran, indole, tetrahydrocarbazole, tetrahydroquinoline, tetrahydro-isoquinoline, benzoxocin, and phenanthridine derivatives, as well as a variety of methylene-spiro compounds can be prepared with this methodology ...


Synthesis Of Allylic And Homoallylic Alcohols Via Organometallic Ring-Opening Of Vinylic Epoxides And Oxetanes , Sandra K. Stolz-Dunn Jan 1989

Synthesis Of Allylic And Homoallylic Alcohols Via Organometallic Ring-Opening Of Vinylic Epoxides And Oxetanes , Sandra K. Stolz-Dunn

Retrospective Theses and Dissertations

Additions of organometallic reagents to vinylic epoxides have become useful synthetic reactions for preparing allylic alcohols when the regio- and stereochemistry of the product can be controlled. Analogous organometallic processes employing vinylic oxetanes have never been reported in the literature. The results presented in this dissertation are the first observed examples of vinylic oxetanes reacting with organometallic reagents to afford homoallylic alcohols. The scope and limitations of these reactions will be discussed;The reactions of aryl- and vinylpalladium compounds with vinylic oxetanes provide a high yielding route to functionally substituted homoallylic alcohols. The homoallylic alcohols are isolated as mixtures of ...


Free Radical Reactions Of Organomercurials , De-Liang Guo Jan 1989

Free Radical Reactions Of Organomercurials , De-Liang Guo

Retrospective Theses and Dissertations

Strong CIDNP multiplet signals (A/E) for RH and R(-H) were observed from the diffusive encounter of primary, secondary or tertiary alkyl radicals during the reaction of RHgX with S[subscript]2O[subscript]sp82-, S[subscript]2O[subscript]sp82-/I[superscript]- or S[subscript]2O[subscript]sp82-/Ag[superscript]+ at room temperature in reactions involving an electron-transfer of S[subscript]H[superscript]2 process. Net polarization effects (E) for R(-H) were observed from the radical pairs [overline]R•• SO[subscript]sp4-[superscript]F or [overline]R•• NO[subscript]3[superscript]F during the reaction of R[subscript]2Hg ...


I. Generation Of Dibromocarbene Under Neutral Conditions; Ii. Generation And Reactions Of 11-Carbena[4.4.1]Propella-3,8-Diene; Iii. The Oxidation Of Cyclopropylidenes , Ramaswamy Gurumurthy Jan 1989

I. Generation Of Dibromocarbene Under Neutral Conditions; Ii. Generation And Reactions Of 11-Carbena[4.4.1]Propella-3,8-Diene; Iii. The Oxidation Of Cyclopropylidenes , Ramaswamy Gurumurthy

Retrospective Theses and Dissertations

Most of the methods of generation of dihalocarbenes involve basic media which are not ideal for reactions with compounds containing base-sensitive groups like -OAc. In an effort to generate:CBr[subscript]2 under neutral conditions, we explored the thermolysis and photolysis of 10,10-dibromotricyclo (4.3.1.0) deca-2,4-diene. Both methods generated:CBr[subscript]2 in good yields, as evidenced by the formation of dibromocyclopropane adducts with olefins like 2-pentene and cyclohexene;In an effort to study whether the tricyclic carbene, 11-carbena (4.4.1) propella-3,8-diene, ring opens to the corresponding allene, we generated the "free" carbene by ...


Preparation And Utilization Of Organopalladium Intermediates , Hanchul Song Jan 1988

Preparation And Utilization Of Organopalladium Intermediates , Hanchul Song

Retrospective Theses and Dissertations

[pi]-Allylpalladium compounds have been prepared from alkenylcycloalkanes bearing 3- and 4-membered rings by reaction with organomercurials and dilithium tetrachloropalladate through a novel palladium-promoted ring-opening process. In the second part of the thesis, [pi]-allylpalladium compounds prepared in situ from various acetoxy-substituted dienes and functionally substituted organomercurials react with base to provide a new route to dihydrobenzofurans and lactones. In the part three of the thesis, cyclic alkenes bearing vinylic halides have been shown to undergo facile, palladium catalyzed cyclization to afford a wide variety of bicyclic cycloalkenes. This methodology allows one to close a 5- or 6-membered ring onto ...


The Transition State Of The Cyclopropylidene To Allene Ring Opening , Robert Jude Sutherland Jan 1988

The Transition State Of The Cyclopropylidene To Allene Ring Opening , Robert Jude Sutherland

Retrospective Theses and Dissertations

As part of an effort to understand the chemistry of cyclopropylidenes in solution, the effects of substituents on the relative rates of cyclopropylidene ring opening versus intermolecular insertion in methanol have been examined via correlation analysis;The trans-2,3-diarylcyclopropylidenes were generated via the base induced decomposition of ethyl N-nitroso N-(trans-2,3-diarylcyclopropyl)carbamates, in various concentrations of methanol, using toluene as the cosolvent. The partitioning of the disubstituted cyclopropylidenes in methanol solution at room temperature was found to be a linear function of the alcohol concentration;The relative cyclopropylidene to allene ring opening rate was found to increase when electron ...


Novel Ring Forming Reactions For Organic Synthesis , Jeffrey J. Thurston Jan 1988

Novel Ring Forming Reactions For Organic Synthesis , Jeffrey J. Thurston

Retrospective Theses and Dissertations

Almost all biologically important molecules contain a ring in their structure. The first two sections of this manuscript deal with general methodology which will facilitate the construction of certain rings. The last part of this manuscript deals with the total synthesis of a natural product containing a tricyclic structure;Part I deals with the preparation of cyclic 1,2-aminoalcohols. Many important natural products contain this substructure. Several recent synthetic methods have been reported for the synthesis of 1,2-aminoalcohols, attesting to the high interest in this area and also to the need for additional methods. Part I deals with the ...