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Amphiphilic Oligocholate Macrocycles: Self-Assembly, Transmembrane Nanopore Formation, And Noncovalent Tuning, Lakmini Sandachaya Widanapathirana 2013 Iowa State University

Amphiphilic Oligocholate Macrocycles: Self-Assembly, Transmembrane Nanopore Formation, And Noncovalent Tuning, Lakmini Sandachaya Widanapathirana

Graduate Theses and Dissertations

A series of rigid amphiphilic oligocholate macrocycles were synthesized and their pore formation in lipid membrane was studied using hydrophilic molecule leakage assays, fluorescence spectroscopy, and solid-state NMR. The exterior of the macrocycles is hydrophobic and thus fully compatible with lipid membrane, whereas the interior is hydrophilic with inwardly facing amide and hydroxyl groups. These amphiphilic cyclic oligocholates could stack over one another to form a transmembrane nanopore driven by a strong tendency of the water molecules in the internal cavities of the macrocycles to aggregate in a nonpolar environment.

To regulate the traffic across the membrane, the nanopore needs ...


Synthesis Of Donor-Acceptor Benzobis(Oxazole) Small Molecules, James Scott Klimavicz 2013 Iowa State University

Synthesis Of Donor-Acceptor Benzobis(Oxazole) Small Molecules, James Scott Klimavicz

Graduate Theses and Dissertations

A variety of symmetric, π-conjugated organic chromophores were synthesized using trans-benzobis(oxazole) as an acceptor and the core of dye, changing the donating moieties in the 2- and 6-positions. The optical and electrical properties of these compounds were investigated for potential use in organic electronic devices, and these compounds exhibited relatively narrow band-gaps, which were tuned by changing the donating group present. Additionally, a significant solvatochromatic effect was noted for some of the dyes. Synthetic routes towards asymmetric chromophores using benzobis(oxazole)s as a π-spacer between an electron-acceptor and donor were also developed, using the orthoester condensation and ...


Synthesis And Modification Of Octafluoro[2.2]Paracyclophane (Parylene Af4), Craig Hicks, Brendan Duffy, Grainne C. Hargaden 2013 Technological University Dublin

Synthesis And Modification Of Octafluoro[2.2]Paracyclophane (Parylene Af4), Craig Hicks, Brendan Duffy, Grainne C. Hargaden

Articles

Parylenes are a class of organic compounds which have gained significant attention due to their application as coatings in areas such as medical devices and electronics. This review highlights the development of synthetic pathways to Octafluoro[2.2]Paracyclophane, commonly referred to as parylene AF4. Methods which have been used to functionalise AF4 are also presented.


Adding Gas Chromatography-Mass Spectrometry Data To A Melting Point And Thin-Layer Chromatography Laboratory, Adam M. Azman, Julie A. Barrett, Megan Darragh, John J. Esteb 2013 Butler University

Adding Gas Chromatography-Mass Spectrometry Data To A Melting Point And Thin-Layer Chromatography Laboratory, Adam M. Azman, Julie A. Barrett, Megan Darragh, John J. Esteb

Scholarship and Professional Work - LAS

The addition of gas chromatography–mass spectrometry (GC–MS) data interpretation to a thin-layer chromatography (TLC) and melting point (mp) laboratory for an introductory organic course is described.


Silylation-Based Kinetic Resolution Of Α-Hydroxy Carbonyl Compounds And Synthesis Of Chiral Isothiourea Catalysts, Yan Zhang 2013 University of South Carolina - Columbia

Silylation-Based Kinetic Resolution Of Α-Hydroxy Carbonyl Compounds And Synthesis Of Chiral Isothiourea Catalysts, Yan Zhang

Theses and Dissertations

The thesis describes the silylation-based kinetic resolution for α-hydroxy carbonyl compounds catalyzed by isothiourea catalyst as well as our effort to make novel chiral isothiourea catalyst.

In Chapter 1, general background will be introduced, including chirality, general methods to obtain enantiopure compounds and kinetic resolution. In Chapter 2, the mechanism of the chiral recognition was discussed and a novel isothiourea catalyst was design to investigate the mechanism. The synthesis of the new catalyst was also described in this chapter.

In Chapter 3, the silylation-based kinetic resolution for α-hydroxy carbonyl compounds will be discussed. Since silylation-based kinetic resolution have already been ...


Synthesis Of Orthogonally Protected Azalanthionines (Lanazanines) By Sequential Ring-Opening Of N-Substituted Aziridine 2-Carboxylates, Keith O'Brien, Keith Ó Proinsias, Fintan Kelleher 2013 Institute of Technology, Tallaght

Synthesis Of Orthogonally Protected Azalanthionines (Lanazanines) By Sequential Ring-Opening Of N-Substituted Aziridine 2-Carboxylates, Keith O'Brien, Keith Ó Proinsias, Fintan Kelleher

Articles

Orthogonally protected azalanthionines (lanazanines, 4-azadiaminopimelic acids or b-aminoalaninoalanines) have been synthesised in good yields by the ring-opening of N-protected aziridine 2-carboxylates with suitably protected diaminopropanoic acids (DAPs). The required DAPs were also synthesised by ring-opening of N-protected aziridine 2-carboxylates with para-methoxybenzylamine.


Iridium Porphyrins: Catalysis, Mechanism, And Structural Studies, Bernie Joe Anding 2013 Iowa State University

Iridium Porphyrins: Catalysis, Mechanism, And Structural Studies, Bernie Joe Anding

Graduate Theses and Dissertations

Prior to this work, metalloporphyrin catalysts containing iron, ruthenium, osmium, cobalt, and rhodium were shown to be active for carbene transfer reactions. These metalloporphyrin catalysts were typically robust, highly reactive, and capable of inducing high selectivities. Furthermore, derivation at the porphyrin periphery by known routes allows for the development of a wide array of sophisticated chiral catalysts. Despite the promising results with other group 9 metal porphyrin complexes, carbene transfer catalysis with iridium porphyrin complexes had not been reported. The present work describes the development of iridium porphyrin-catalyzed cyclopropanation, C–H insertion, and N–H insertion reactions. These reactions were ...


Efficient Electrochemical Functionalization Of Carbon Nanotubes And Carbon Nanotube Membranes For Energy, Drug Delivery And Potential Catalysis Applications, Xin Zhan 2013 University of Kentucky

Efficient Electrochemical Functionalization Of Carbon Nanotubes And Carbon Nanotube Membranes For Energy, Drug Delivery And Potential Catalysis Applications, Xin Zhan

Theses and Dissertations--Chemistry

Electrochemical diazonium grafting offers versatile functionalization of chemically inert graphite under mild condition, which is particularly suitable for CNT composite modification. Tetrafluorinated carboxylphenyl diazonium grafting provides the most controllable functionalization chemistry allowing near monolayer levels of functionality on carbon nanotubes. The functional density was successfully quantified by anion selective dye-assay and X-ray photoelectron spectroscopy (XPS) of thiol-Au self-assembled monolayers (SAM) as a calibration reference. This technique enables monolayer functionality at the tips of carbon nanotube membranes for biomimetic pumps and valves as well as thin conductive layers for CNT-based high area electrochemical support electrodes.

Double-walled carbon nanotube (DWCNT) membranes were ...


N-Doped Multiwalled Carbon Nanotubes: Functionalization, Characterization And Application In Li Ion Batteries, Aman Preet Kaur 2013 University of Kentucky

N-Doped Multiwalled Carbon Nanotubes: Functionalization, Characterization And Application In Li Ion Batteries, Aman Preet Kaur

Theses and Dissertations--Chemistry

The focus of this dissertation is to utilize chemical functionalization as a probe to investigate the reactivity of N-doped multiwalled carbon nanotubes (N-MWCNTs). The surface of N-MWCNTs, being a set of potentially reactive graphene edges, provides a large number of reactive sites for chemical modification, so considerable changes in chemical and physical properties can be envisaged. We observed that both reduction (dissolving metal reduction/alkylation) and oxidation (H2SO4/HNO3 and H2SO4/KMnO4 mixtures) of N-MWCNTs lead to formation of interesting spiral channels and spiraled carbon nanoribbons. A variety of techniques, including TGA ...


Acenes And Acenequinones For Optics And Organic Electronics, Matthew Bruzek 2013 University of Kentucky

Acenes And Acenequinones For Optics And Organic Electronics, Matthew Bruzek

Theses and Dissertations--Chemistry

Acenes have been explored by a number of research groups in the field of organic electronics with a particular emphasis on transistor materials. This group has been actively studying acene‐based organic semiconductors for more than a decade using a crystal engineering approach and has developed acene derivatives for applications in field‐effect transistors, light‐emitting diodes, and photovoltaics. In addition to organic electronics, crystal engineering has important applications in a number of other fields, quite notably in the design of metal‐organic frameworks. Chapters 2 and 3 of this dissertation focus on applying crystal engineering to the synthesis of ...


Fluorinated Arene, Imide And Unsaturated Pyrrolidinone Based Donor Acceptor Conjugated Polymers: Synthesis, Structure-Property And Device Studies, Arawwawala Don T. Liyanage 2013 University of Kentucky

Fluorinated Arene, Imide And Unsaturated Pyrrolidinone Based Donor Acceptor Conjugated Polymers: Synthesis, Structure-Property And Device Studies, Arawwawala Don T. Liyanage

Theses and Dissertations--Chemistry

FLUORINATED ARENE, IMIDE AND LACTAM-FUNCTIONALIZED DONOR ACCEPTOR CONJUGATED POLYMERS: SYNTHESIS, STRUCTURE-PROPERTY AND DEVICE STUDIES

After the discovery of doped polyacetylene, organic semiconductor materials are widely studied as high impending active components in consumer electronics. They have received substantial consideration due to their potential for structural tailoring, low cost, large area and mechanically flexible alternatives to common inorganic semiconductors. To acquire maximum use of these materials, it is essential to get a strong idea about their chemical and physical nature. Material chemist has an enormous role to play in this novel area, including development of efficient synthetic methodologies and control the ...


Chiral Binaphthoquinones: Versatile Precursors For The Synthesis Of Natural Products And Ligands For Asymmetric Catalysis, Erin Podlesny 2013 University of Pennsylvania

Chiral Binaphthoquinones: Versatile Precursors For The Synthesis Of Natural Products And Ligands For Asymmetric Catalysis, Erin Podlesny

Publicly Accessible Penn Dissertations

The efforts described in this dissertation initially focus on the asymmetric synthesis of axially chiral binaphtho-para- and binaphtho-ortho-quinones, followed by an exploration of their utility in natural product synthesis, development of ligands for asymmetric catalysis, and development as potential sensors. Axially chiral binaphtho-para- and in-in-binaphtho-ortho-quinones were synthesized through a concerted route involving the enantioselective coupling of a hindered 8-substituted 2-naphthol, with a diaza-cis-decalin copper catalyst developed previously by the Kozlowski group. The coupling was achieved in 62% yield and 87% ee (a single trituration produced material of >99% ee). Subsequent transformations ...


Design, Synthesis And Suzuki-Miyaura Cross-Coupling Reactions Of Potassium Organotrifluoroborates, Inji Shin 2013 University of Pennsylvania

Design, Synthesis And Suzuki-Miyaura Cross-Coupling Reactions Of Potassium Organotrifluoroborates, Inji Shin

Publicly Accessible Penn Dissertations

The Suzuki–Miyaura cross-coupling reaction is one of the most efficient methods to form new carbon-carbon bonds, allowing a rapid increase in complexity among target molecules of interest. Among a variety of boron reagents utilized in Suzuki–Miyaura reactions, potassium organotrifluoroborates are of great interest because they have many advantages over other boron reagents. Organotrifluoroborates, which are tetracoordinate boron species, show better stability and reactivity, and they are much less prone to protodeboronation.

α-Chiral β-arylated carbonyl compounds are important substructures in organic chemistry, and their preparations, such as benzylations, asymmetric hydrogenations, and conjugate additions, have been studied. However, these methods ...


Reversing Diastereoselectivity: Chelation-Controlled Addition Of Organozincs To Chiral Carbonyl Derivatives, Gretchen Rachelle Stanton 2013 University of Pennsylvania

Reversing Diastereoselectivity: Chelation-Controlled Addition Of Organozincs To Chiral Carbonyl Derivatives, Gretchen Rachelle Stanton

Publicly Accessible Penn Dissertations

A conventional approach in the construction of complex molecules is to use existing substrate stereochemistry to direct the introduction of new stereogenic centers. Since Cram's original studies 1952, the Felkin–Anh, Cornforth–Evans, and Cram-chelation models were developed and have been widely utilized to predict stereochemical outcomes in nucleophilic additions to aldehydes and ketones bearing a proximal chiral center. Specifically, nucleophilic additions to protected α- and β-hydroxy aldehydes and ketones is protecting group dependent. Small protecting groups such as methyl or benzyl undergo carbonyl addition via a chelation-controlled mechanism. In contrast, sterically encumbered silyl protecting groups preclude chelation and ...


Total Synthesis Of (+)-18-Epi-Latrunculol A, Brett Daniel Williams 2013 University of Pennsylvania

Total Synthesis Of (+)-18-Epi-Latrunculol A, Brett Daniel Williams

Publicly Accessible Penn Dissertations

The total synthesis of (+)-18-epi-latrunculol A was undertaken to provide synthetic access to a sufficient amount of the scarce, sponge-derived macrolide to facilitate further biological evaluation. Preliminary bioassays revealed (+)-18-epi-latrunculol A to exhibit a selective, solid tumor cytotoxicity, while being devoid of the actin depolymerization activity customary to the latrunculin family of natural products, making the epimeric natural product a compound of interest for chemotherapeutics. An enantioselective total synthesis of (+)-18-epi-latrunculol A was accomplished; key features of the synthesis include a functional group compatible cross metathesis reaction, an acid mediated cyclization/equilibration, a Carreira alkynylation, and a late-stage Mitsunobu macrolactonization ...


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, Saptarshi De 2013 Wayne State University

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, Saptarshi De

Wayne State University Dissertations

A facile and short stereoselective synthesis of the functionalized tetracyclic core structure of the cyclocitrinols, a family of unusual C25 steroid isomers, has been accomplished. The key structural unit, the bicyclo[4.4.1]A/B ring system, was constructed by a regioselective Cr(0)-promoted [6π + 4π] photochemical cycloaddition reaction.

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 moiety was found to be crucial for the rapid transformation which is believed to proceed via carbocation intermediates ...


Synthesis And Application Of Atp Analogs For Phosphorylation-Dependent Kinase-Substrate Crosslinking, Satish Kumar Garre Venkata Raghavendra 2013 Wayne State University

Synthesis And Application Of Atp Analogs For Phosphorylation-Dependent Kinase-Substrate Crosslinking, Satish Kumar Garre Venkata Raghavendra

Wayne State University Dissertations

Phosphorylation is an important post-translational modification that plays a key role in a variety of signaling cascades and cellular functions. Kinases phosphorylate protein substrates in a highly regulated manner and are promiscuous. Understanding kinase-substrate specificity has been challenging and there is a need for new chemical tools. To this end we developed -phosphate modified ATP photocrosslinking analogs ATP-ArN3 and ATP-BP, that crosslink substrate and kinase in a phosphorylation dependent manner. We have successfully demonstrated that ATP-ArN3 and ATP-BP can be used with natural kinase and substrates using cell lysates in vitro. We used our approach to identify novel kinases of ...


Applications Of Type Ii Anion Relay Chemistry (Arc) Part 1: Diversity-Oriented Synthesis Of Polysubstituted Piperidine Analogues Via Type Ii Arc, Part 2: A Highly Convergent Synthesis Of (-)-Secu'amamine A Exploiting Type Ii Arc, Part 3: Facile Access To Diverse Carbobicyclic Systems Via Type Ii Arc, Heeoon Han 2013 University of Pennsylvania

Applications Of Type Ii Anion Relay Chemistry (Arc) Part 1: Diversity-Oriented Synthesis Of Polysubstituted Piperidine Analogues Via Type Ii Arc, Part 2: A Highly Convergent Synthesis Of (-)-Secu'amamine A Exploiting Type Ii Arc, Part 3: Facile Access To Diverse Carbobicyclic Systems Via Type Ii Arc, Heeoon Han

Publicly Accessible Penn Dissertations

In this dissertation, three successful applications of Type II Anion Relay Chemistry (ARC), a versatile multi-component union tactic, are described.

Part 1: An effective, general protocol for the Diversity-Oriented Synthesis (DOS) of 2,4,6-trisubstituted piperidine congeners has been designed and validated. The successful strategy entails a modular approach to all possible stereoisomers of a selected piperidine scaffold, exploiting Type II Anion Relay Chemistry (ARC), followed in turn by intramolecular SN2 cyclization, chemoselective removal of the dithiane moieties and carbonyl reductions.

Part 2: A highly convergent synthesis of (-)-secu'amamine A has been achieved by exploiting a highly efficient Type ...


Synthesis Of 3-Farnesyl Salicylic Acid, A Novel Antimicrobial From Piper Multiplinervium, George A. Kraus, Divya Chaudharya, Sean Riley, Feng Liu, Allison Schlapkohl, Megan Weems, Gregory J. Phillips 2013 Iowa State University

Synthesis Of 3-Farnesyl Salicylic Acid, A Novel Antimicrobial From Piper Multiplinervium, George A. Kraus, Divya Chaudharya, Sean Riley, Feng Liu, Allison Schlapkohl, Megan Weems, Gregory J. Phillips

Chemistry Publications

Both 3-farnesyl salicylic acid and 3-geranyl salicylic acid were synthesized from 2,6-dibromophenol and showed low levels of antimicrobial activity against E. coli strains.


Adaptation Of An Instrument For Measuring The Cognitive Complexity Of Organic Chemistry Exam Items, Jeffrey R. Raker, Jaclyn M. Trate, Thomas Holme, Kristen Murphy 2013 Iowa State University

Adaptation Of An Instrument For Measuring The Cognitive Complexity Of Organic Chemistry Exam Items, Jeffrey R. Raker, Jaclyn M. Trate, Thomas Holme, Kristen Murphy

Chemistry Publications

Experts use their domain expertise and knowledge of examinees’ ability levels as they write test items. The expert test writer can then estimate the difficulty of the test items subjectively. However, an objective method for assigning difficulty to a test item would capture the cognitive demands imposed on the examinee as well as be assignable by any domain expert familiar with the examinee group. One such instrument for assigning objective complexity of general chemistry exam items has already been reported. A revised instrument for assigning objective complexity of organic chemistry exam items is presented including the reliability and validity studies ...


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