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Chiral Phosphoric Acid-Catalyzed Acetalization And Iso-Pictet-Spengler Reactions, Matthew Jon Kaplan 2013 University of South Florida

Chiral Phosphoric Acid-Catalyzed Acetalization And Iso-Pictet-Spengler Reactions, Matthew Jon Kaplan

Graduate Theses and Dissertations

The development of novel asymmetric reaction methodologies has been invaluable in both the academic and industrial world. In just 15 years, organocatalysis has provided a new means of developing asymmetric reaction methodologies using catalysts that are environmentally benign, relatively inexpensive, bench stable, and non-toxic. One development in organocatalysis that is important to our group in particular is chiral phosphoric acid-catalysis. BINOL-derived and VAPOL-derived phosphoric acids have proven to be excellent catalysts for a number of reactions.

The two projects I will discuss my efforts on are acetalization and iso-Pictet-Spengler reactions. These were projects that I performed during my first two ...


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 ...


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 ...


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.


Role Of Extractable And Residual Organic Matter Fractions On Sorption Of Phenanthrene In Sediments, Yulong Zhang, Yong Ran, Jingdong Mao 2013 Old Dominion University

Role Of Extractable And Residual Organic Matter Fractions On Sorption Of Phenanthrene In Sediments, Yulong Zhang, Yong Ran, Jingdong Mao

Chemistry & Biochemistry Faculty Publications

Two sediments were demineralized and sequentially fractionated into extracted fractions [free lipid (FL), bound lipid (BL) and lignin (LG)] and residual fractions [free lipid free (FLF), bound lipid free (BLF) and lignin free (LGF)]. The sorption isotherms of phenanthrene (Phen) were examined to evaluate the importance of various fractions on sorption. A lignin extraction procedure was for the first time applied to separate the lignin or degraded lignin fraction from sediment organic matter (SOM). The extracted LG was similar to model lignin in terms of elemental ratios and sorption behavior. FL and LG fractions were quite important, as their contents ...


Silver Nanoparticles Induce Developmental Stage-Specific Embryonic Phenotypes In Zebrafish, Kerry J. Lee, Lauren M. Browning, Prakash D. Nallathamby, Christopher J. Osgood, Xiao-Hong Nancy Xu 2013 Old Dominion University

Silver Nanoparticles Induce Developmental Stage-Specific Embryonic Phenotypes In Zebrafish, Kerry J. Lee, Lauren M. Browning, Prakash D. Nallathamby, Christopher J. Osgood, Xiao-Hong Nancy Xu

Chemistry & Biochemistry Faculty Publications

Much is anticipated from the development and deployment of nanomaterials in biological organisms, but concerns remain regarding their biocompatibility and target specificity. Here we report our study of the transport, biocompatibility and toxicity of purified and stable silver nanoparticles (Ag NPs, 13.1 ± 2.5 nm in diameter) upon the specific developmental stages of zebrafish embryos using single NP plasmonic spectroscopy. We find that single Ag NPs passively diffuse into five different developmental stages of embryos (cleavage, early-gastrula, early-segmentation, late-segmentation, and hatching stages), showing stage-independent diffusion modes and diffusion coefficients. Notably, the Ag NPs induce distinctive stage and dose-dependent phenotypes ...


Evaluating Chalcogen Heteroatoms In Conjugated Polymers For Organic Electronics, Brandon Michael Kobilka 2013 Iowa State University

Evaluating Chalcogen Heteroatoms In Conjugated Polymers For Organic Electronics, Brandon Michael Kobilka

Graduate Theses and Dissertations

In recent years, alternating electron-donating and electron-acceptor (D-A) conjugated copolymers are among the best materials being used to fabricate high-efficiency bulk-heterojunction organic photovoltaics (BHJ-OPVs). Thiophene and thiophene-based aromatic molecules are typically used in the design and construction of these materials due to their ability to impart good film-forming and charge transport properties as well as their synthetic robustness. Among thiophene-based molecules benzo[1,2-b:4,5-b']dithiophene (BDT) has been incorporated into numerous, high-efficiency OPVs. This dissertation reports on the synthesis and characterization of the analogous oxygen- and selenium-containing functionalized benzodifuran (BDF) and benzodiselenophene (BDSe) and their incorporation ...


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 ...


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 ...


Preparation Of Phosphonoterephthalic Acids Via Palladium-Catalyzed Coupling Of Aromatic Iodoesters, Nathaniel Ivan, Vladimir Benin, Alexander Morgan 2013 University of Dayton

Preparation Of Phosphonoterephthalic Acids Via Palladium-Catalyzed Coupling Of Aromatic Iodoesters, Nathaniel Ivan, Vladimir Benin, Alexander Morgan

Chemistry Faculty Publications

The current article reports in detail the preparation of two phosphonoterephthalic acids: 2-phosphonoterephthalic acid (1) and 2,5-diphosphonoterephthalic acid (2). Efficient, scalable syntheses have been developed for both compounds based on Pd-catalyzed coupling reactions of iodinated terephthalate esters. Phosphonoterephthalic acids are potentially useful as flame-retardant additives or as monomers for the construction of acid-pendant polymer chains.


Reaction Between Polyol-Esters And Phosphate Esters In The Presence Of Metal Carbides, David W. Johnson, Carolyn Iacullo, John E. Hils 2013 University of Dayton

Reaction Between Polyol-Esters And Phosphate Esters In The Presence Of Metal Carbides, David W. Johnson, Carolyn Iacullo, John E. Hils

Chemistry Faculty Publications

The reaction of metal carbides with polyol esters found in aerospace lubricants and phosphate esters commonly used as additives was investigated. Carbides were of particular interest since modern materials under consideration at high temperature bearings have surfaces that are primarily metal carbides. Vanadium and chromium carbide were found to react with the ester and phosphate ester by a transesterification reaction, producing an alkyl phosphate which is less stable than the aromatic phosphate esters. In the process, the metal carbide is converted to the metal phosphate and metal polyphosphate, evidenced by the infrared and Raman spectra of the solid residue and ...


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 Technological University Dublin

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.


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 ...


Oligodeoxynucleotide Synthesis Using Protecting Groups And A Linker Cleavable Under Non-Nucleophilic Conditions, Xi Lin 2013 Michigan Technological University

Oligodeoxynucleotide Synthesis Using Protecting Groups And A Linker Cleavable Under Non-Nucleophilic Conditions, Xi Lin

Dissertations, Master's Theses and Master's Reports - Open

Oligodeoxynucleotides (ODNs) containing latent electrophilic groups can be highly useful in antisense drug development and many other applications such as chemical biology and medicine, where covalent cross-linking of ODNs with mRNA, protein and ODN is required. However, such ODN analogues cannot be synthesized using traditional technologies due to the strongly nucleophilic conditions used in traditional deprotection/cleavage process.

To solve this long lasting and highly challenging problem in nucleic acid chemistry, I used the 1,3-dithian-2-yl-methoxycarbonyl (Dmoc) function to protect the exo-amino groups on the nucleobases dA, dC and dG, and to design the linker between the nascent ODN and ...


Gold’S Structural Versatility Within Complex Intermetallics: From Hume-Rothery To Zintl And Even Quasicrystals, Gordon J. Miller, Srinivasa Thimmaiah, Volodymyr Smetana, Andriy Palasyuk, Qisheng Lin 2013 Iowa State University

Gold’S Structural Versatility Within Complex Intermetallics: From Hume-Rothery To Zintl And Even Quasicrystals, Gordon J. Miller, Srinivasa Thimmaiah, Volodymyr Smetana, Andriy Palasyuk, Qisheng Lin

Chemistry Conference Papers, Posters and Presentations

Recent exploratory syntheses of polar intermetallic compounds containing gold have established gold’s tremendous ability to stabilize new phases with diverse and fascinating structural motifs. In particular, Au-rich polar intermetallics contain Au atoms condensed into tetrahedra and diamond-like three-dimensional frameworks. In Au-poor intermetallics, on the other hand, Au atoms tend to segregate, which maximizes the number of Au-heteroatom contacts. Lastly, among polar intermetallics with intermediate Au content, complex networks of icosahedra have emerged, including discovery of the first sodium-containing, Bergman-type, icosahedral quasicrystal. Gold’s behavior in this metal-rich chemistry arises from its various atomic properties, which influence the chemical bonding ...


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