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I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta 2010 Wayne State University

I-Kinetic And Mechanistic Investigations Of Amino Acid Substrates Reactivities With Ferryl Species, Ahmed Ibrahim Youssef Abouelatta

Wayne State University Dissertations

ABSTRACT

I-KINETIC AND MECHANISTIC INVESTIGATIONS OF AMINO ACID SUBSTRATES REACTIVITIES WITH FERRYL SPECIES

II-SYNTHESIS AND CHARACTERIZATION OF DERIVATIVES OF THE BN-TPEN LIGAND AND THEIR METAL COMPLEXES

by

AHMED IBRAHIM YOUSSEF ABOUELATTA

MAY 2011

Advisor: Dr. Jeremy Jacob Kodanko

Major: Chemistry (Organic)

Degree: Doctor of philosophy

The reactivity of tryptophan, methionine, aspartic acid, glutamic acid, histidine and hydrochloride salt of lysine amino acid substrates with the N4Py ferryl species was studied by UV-vis spectroscopy and product characterization. Based on kinetic isotope effect studies and product analysis, an ET-PT mechanism was proposed for the reaction of tryptophan substrate with N4Py ferryl and ...


A Bioarchaeological Study Of A Prehistoric Michigan Population: Fraaer-Tyra Site (20sa9), Allison June Muhammad 2010 Wayne State University

A Bioarchaeological Study Of A Prehistoric Michigan Population: Fraaer-Tyra Site (20sa9), Allison June Muhammad

Wayne State University Dissertations

ABSTRACT

The Saginaw Valley Region has been the focus of Michigan archaeology for many decades. The Late Woodland period of the Saginaw Valley has been characterized as an area that prehistoric people abandoned as a permanent resident, but exploited seasonally during times of scarcity. Furthermore, the valley's resources were exploited by a diverse group of prehistoric peoples, both native to Michigan and those Mississippian `intruders' (Halsey 1976; Holman and Brashler 1999; Norder et al. 2003; Stothers 1999). Though previous studies of the Frazer-Tyra site (20SA9) have included ceramic and lithic analysis (Andrews 1995; Halsey 1976) and a study of ...


Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation, Venkataraman Subramanian 2010 Wayne State University

Dechalcogenative Allylic Selenosulfide And Disulfide Rearrangements For Cysteine Modification And Glycoligation, Venkataraman Subramanian

Wayne State University Dissertations

This thesis describes investigations directed at the development of methods for the selenosulfide and disulfide rearrangements for the permanent functionalization of thiols, and in particular of cysteine and carbohydrate based thiols. Emphasis is placed on the newly invented silver mediated allylic desulfurative rearrangement for the primary modification of thiols and the synthesis of complex oligosaccharide mimics.

Chapter one introduces the concept of chemoselective ligations for the modification of macromolecules like carbohydrates and proteins. It overviews the native and non-native ligation techniques for their modification of such entities with a attention focusing on thiol based ligation techniques. The later part of ...


I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra 2010 Wayne State University

I. Microwave-Influenced Diversity-Oriented Synthesis Of Biologically Relevant Small & Natural-Product-Like Molecules Via Multicomponent Coupling Reactions Ii. Synthetic Studies Toward The Total Synthesis Of The Repeating Tetrasaccharide Unit Of Zwitterionic Polysaccharide Ps A1, Soumava Santra

Wayne State University Dissertations

Microwave-influenced diversity-oriented synthesis of biologically relevant small and natural-product-like molecules via multicomponent coupling reactions (MCCRs) have been investigated. Cheap, readily available starting materials in conjunction of microwave irradiation and employment of environmentally benign solvent (e.g. water) provided a common platform that allowed to access a wide array of structurally and skeletally diverse molecules. The investigation allowed us to establish a new paradigm of diversity-activity relationships (DARs) by tuning reacting components of the MCCRs and proved that in contrary to the conventional use of microwave as a rate accelerating tool, it can be used to influence reactivity of molecules. The ...


Novel Photochemical Methodologies For Diversity Oriented Synthesis And Screening Of Combinatorial Libraries, Roman Askatovich Valiulin 2010 University of Denver

Novel Photochemical Methodologies For Diversity Oriented Synthesis And Screening Of Combinatorial Libraries, Roman Askatovich Valiulin

Electronic Theses and Dissertations

The main goal of this project was to develop an efficient methodology allowing rapid access to structurally diverse scaffolds decorated with various functional groups.

Initially, we discovered and subsequently developed an experimentally straightforward, high-yielding photoinduced conversion of readily accessible diverse starting materials into polycyclic aldehydes and their (hemi)acetals decorated by various pendants. The two step sequence, involving the Diels-Alder addition of heterocyclic chalcones and other benzoyl ethylenes to a variety of dienes, followed by the Paternò-Büchi reaction, was described as an alkene-carbonyl oxametathesis. This methodology offers a rapid increase in molecular complexity and diversity of the target scaffolds.

To ...


Microporous Organic Polymers: Synthesis And Post Synthetic Modifications, Phillip Andrew Kerneghan 2010 Wilfrid Laurier University

Microporous Organic Polymers: Synthesis And Post Synthetic Modifications, Phillip Andrew Kerneghan

Theses and Dissertations (Comprehensive)

Microporous solids are an important class of materials that have been studied extensively. Newer to this field are Microporous Organic Polymers (MOPs) which are networks constructed from smaller organic building blocks and exhibit large surface areas, small pore sizes and low densities. It is due to these characteristics that MOPs have attracted attention because of their potential use in applications such as catalysis, chemical separations and gas storage.

In this thesis is described the synthesis of two novel MOPs, the first of which being a network based on benzenediboronic acid and triptycene building blocks linked together by boronate esters. This ...


1, 2-Bis (Phenylsulfonyl)-1h-Indole As An Acceptor Of Organocuprate Nucleophiles, David C. Qian, Philip E. Alford, Tara L. S. Kishbaugh, Sean T. Jones, Gordon W. Gribble 2010 Dartmouth College

1, 2-Bis (Phenylsulfonyl)-1h-Indole As An Acceptor Of Organocuprate Nucleophiles, David C. Qian, Philip E. Alford, Tara L. S. Kishbaugh, Sean T. Jones, Gordon W. Gribble

Open Dartmouth: Faculty Open Access Articles

1,2-Bis(phenylsulfonyl)-1H-indole is a novel example of an electron-deficient indole that undergoes nucleophilic attack at C-3. Though a variety of other organometallic nucleophiles fail to engender nucleophilic substitution, organocuprates produce 3-substituted 2-(phenylsulfonyl)-1H-indoles. These reactions contribute to the growing number of examples of nucleophilic addition to the indole core.


Effluent Organic Nitrogen (Eon): Bioavailability And Photochemical And Salinity-Mediated Release, Deborah A. Bronk, Quinn N. Roberts, Marta P. Sanderson, Elizabeth A. Canuel, Patrick G. Hatcher, Rajaa Mesfioui, Katherine C. Filippino, Margaret R. Mulholland, Nancy G. Love 2010 Old Dominion University

Effluent Organic Nitrogen (Eon): Bioavailability And Photochemical And Salinity-Mediated Release, Deborah A. Bronk, Quinn N. Roberts, Marta P. Sanderson, Elizabeth A. Canuel, Patrick G. Hatcher, Rajaa Mesfioui, Katherine C. Filippino, Margaret R. Mulholland, Nancy G. Love

Chemistry & Biochemistry Faculty Publications

The goal of this study was to investigate three potential ways that the soluble organic nitrogen (N) fraction of wastewater treatment plant (WWTP) effluents, termed effluent organic N (EON), could contribute to coastal eutrophication - direct biological removal, photochemical release of labile compounds, and salinity-mediated release of ammonium (NH4+). Effluents from two WWTPs were used in the experiments. For the bioassays, EON was added to water from four salinities (∼0 to 30) collected from the James River (VA) in August 2008, and then concentrations of N and phosphorus compounds were measured periodically over 48 h. Bioassay results, based on changes ...


Sequence And Structural Analysis Of The Chitinase Insertion Domain Reveals Two Conserved Motifs Involved In Chitin Binding, Hai Li, Lesley H. Greene 2010 Old Dominion University

Sequence And Structural Analysis Of The Chitinase Insertion Domain Reveals Two Conserved Motifs Involved In Chitin Binding, Hai Li, Lesley H. Greene

Chemistry & Biochemistry Faculty Publications

Background: Chitinases are prevalent in life and are found in species including archaea, bacteria, fungi, plants, and animals. They break down chitin, which is the second most abundant carbohydrate in nature after cellulose. Hence, they are important for maintaining a balance between carbon and nitrogen trapped as insoluble chitin in biomass. Chitinases are classified into two families, 18 and 19 glycoside hydrolases. In addition to a catalytic domain, which is a triosephosphate isomerase barrel, many family 18 chitinases contain another module, i.e., chitinase insertion domain. While numerous studies focus on the biological role of the catalytic domain in chitinase ...


An Improved Synthesis Of A Ring-C Precursor To Cobyric Acid, Hui Wang, Peter A. Jacobi 2010 Dartmouth College

An Improved Synthesis Of A Ring-C Precursor To Cobyric Acid, Hui Wang, Peter A. Jacobi

Open Dartmouth: Faculty Open Access Articles

Alkyne acid 10 was prepared in enantioselective fashion from allylic ester derivative (R)-18 via an E-selective Ireland-Claisen rearrangement followed by Si-assisted elimination of HBr. The present route offers significant advantages in terms of both scalability and overall yield compared to that previously described. Alkyne acid 10 is an attractive ring-C precursor for an ongoing synthesis of cobyric acid.


Substituent Effects On The E/Z Alkene Ratio In Medium-Membered Rings Synthesized Via Rcm, Cezar B. Rodarte 2010 University of Redlands

Substituent Effects On The E/Z Alkene Ratio In Medium-Membered Rings Synthesized Via Rcm, Cezar B. Rodarte

Undergraduate Honors Theses

Ring closing metathesis (RCM) reactions using Grubb's 1st generation catalyst form rings with an alkene. If the ring size permits, then a mixture of E and Z products can result but the dominant isomer cannot be predicted. By synthesizing a series of substituted 10-membered lactones and measuring the resulting E/Z ratios after RCM we are examining how steric effects control the stereoselectivity of the reaction. differences in the relative stabilities of E and Z RCM intermediates have been explored computationally at the DFT-B3LYP level of theory for series of methyl substituted and t-butyl substituted 10-membered lactones. For ...


Technology For The Organic Chemist: Three Exploratory Modules, John J. Esteb, LuAnne M. McNulty, John Magers, Paul Morgan 2010 Butler University

Technology For The Organic Chemist: Three Exploratory Modules, John J. Esteb, Luanne M. Mcnulty, John Magers, Paul Morgan

Scholarship and Professional Work - LAS

The ability to use computer-based technology is an essential skill set for students majoring in chemistry. This exercise details the introduction of appropriate uses for this technology in the organic chemistry series. The incorporation of chemically appropriate online resources (module 1), scientific databases (module 2), and the use of a chemical drawing program (module 3) are detailed here.


Analysis Of The Electron Withdrawing Capability Of Acetylene Groups For Promoting Nucleophilic Aromatic Substitution, Eric D. Braunstein 2010 Colby College

Analysis Of The Electron Withdrawing Capability Of Acetylene Groups For Promoting Nucleophilic Aromatic Substitution, Eric D. Braunstein

Honors Theses

It is well known that electron withdrawing groups, such as nitro or carbonyl groups, activate benzene rings for nucleophilic aromatic substitution. However, little research has been done to investigate the electron withdrawing capability of acetylene groups for substitution of aromatic halides. Experimental and computational investigations on the reactivity of halogenated phenylacetylenes with oxygen and other nucleophiles will be described.


Synthesis Of Novel Glycosylidene-Based Quinolines, Peter H. Dobbelaar 2010 Seton Hall University

Synthesis Of Novel Glycosylidene-Based Quinolines, Peter H. Dobbelaar

Seton Hall University Dissertations and Theses (ETDs)

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Approaches Towards The Synthesis Of Bradyoxetin, Vanildo Martins Lima Braga 2010 University of Mississippi

Approaches Towards The Synthesis Of Bradyoxetin, Vanildo Martins Lima Braga

Electronic Theses and Dissertations

Quorum sensing bacteria produce and release chemical signal molecules (like N-acyl homoserine lactones, AHL) that increase in concentration as a function of cell density. The responses cover a large spectrum of process such as the virulence in Staphylococcus aureus, competence for DNA-uptake in Bacillus subtilis and Streptococcus pneumoniae, sporulation in Bacillus subtilis, conjugal plasmid transfer in Enterococcus faecalis, and bacteriocin production in lactic acid bacteria. The collapse of (AHL) signaling system in bacteria represents an attractive therapeutic approach towards the development of new antibiotics. Recently, a new extracellular modulator was isolated from a symbiotic bacterium (Bradyrhizobium japonicum) that nodulates soybean ...


Technology For The Organic Chemist: Three Exploratory Modules, John Esteb, LuAnne McNulty, John Magers, Paul Morgan, Anne Wilson 2009 Butler University

Technology For The Organic Chemist: Three Exploratory Modules, John Esteb, Luanne Mcnulty, John Magers, Paul Morgan, Anne Wilson

John Esteb

The ability to use computer-based technology is an essential skill set for students majoring in chemistry. This exercise details the introduction of appropriate uses for this technology in the organic chemistry series. The incorporation of chemically appropriate online resources (module 1), scientific databases (module 2), and the use of a chemical drawing program (module 3) are detailed here.

Note: Link is to the article in a subscription database available to users affiliated with Butler University. Appropriate login information will be required for access. Users not affiliated with Butler University should contact their local librarian for assistance in locating a copy ...


Bismuth(Iii) Triflate Catalyzed Allylation Of Cyclic Acetals And Dithianes Followed By In Situ Derivatization To Generate Highly Functionalized Esters, Ram Mohan, Scott Krabbe, Matthew Spafford 2009 Illinois Wesleyan University

Bismuth(Iii) Triflate Catalyzed Allylation Of Cyclic Acetals And Dithianes Followed By In Situ Derivatization To Generate Highly Functionalized Esters, Ram Mohan, Scott Krabbe, Matthew Spafford

Ram S. Mohan

No abstract provided.


Kinetic And Mechanistic Studies Of The Deuterium Exchange In Classical Keto−Enol Tautomeric Equilibrium Reactions, Michael Nichols, Mark Waner 2009 John Carroll University

Kinetic And Mechanistic Studies Of The Deuterium Exchange In Classical Keto−Enol Tautomeric Equilibrium Reactions, Michael Nichols, Mark Waner

Michael A Nichols

An extension of the classic keto−enol tautomerization of β-dicarbonyl compounds into a kinetic analysis of deuterium exchange is presented. It is shown that acetylacetone and ethyl acetoacetate undergo nearly complete deuterium exchange of the α-methylene carbon when dissolved in methanol-d4. The extent of deuteration may be monitored via NMR spectroscopy as a function of time. A mechanism for deuterium exchange is presented and shown to be consistent with a consecutive first-order process. The data for acetylacetone are consistent with steady-state kinetics, whereas those of ethyl acetoacetate illustrate nonsteady-state behavior, offering an accessible example where students might collect and analyze ...


Bismuth Compounds In Organic Synthesis: Synthesis Of Dioxanes, Dioxepines, And Dioxolanes Catalyzed By Bismuth(Iii) Triflate, Ram Mohan, Daniel Podgorski, Scott Krabbe, Long Le, Paul Sierszulski 2009 Illinois Wesleyan University

Bismuth Compounds In Organic Synthesis: Synthesis Of Dioxanes, Dioxepines, And Dioxolanes Catalyzed By Bismuth(Iii) Triflate, Ram Mohan, Daniel Podgorski, Scott Krabbe, Long Le, Paul Sierszulski

Ram S. Mohan

A simple method for the synthesis of l,3-dioxolanes from carbonyl compounds has been developed using l,2-bis(trimethylsilyloxy) ethane in the presence of bismuth (III) triflate as a catalyst. The bismuth(III) triflate catalyzed synthesis of a range of dioxanes and dioxepines has also been developed. In these latter cases, the carbonyl compound is treated with a diol, and triethyl orthoformate is used as a water scavenger. All these methods avoid the use of a Dean-Stark trap.


A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst, Ram S. Mohan, Jason M. Bothwell, Veronica V. Angeles, James P. Carolan, Margaret E. Olson 2009 Illinois Wesleyan University

A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst, Ram S. Mohan, Jason M. Bothwell, Veronica V. Angeles, James P. Carolan, Margaret E. Olson

Ram S. Mohan

The most common method for the deprotection ofTBDMS ethers utilizes stoichiometric amounts of tetrabutylammonium fluoride, n-Bu4N+F(TBAF), which is highly corrosive and toxic. We have developed a mild and chemoselective method for the deprotection ofTBDMS, TES, and TIPS ethers using iron(III) tosylate as a catalyst. Phenolic TBDMS ethers, TBDPS ethers and the BOC group are not affected under these conditions. Iron(III) tosylate is an inexpensive, commercially available, and non-corrosive reagent.


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