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Showing 1 to 20 of 23 for “"Regioisomer"”.

  1. Aspects of the chemistry of 1,4-naphthoquinones. An investigation of nucleophilic substitution reactions of alkylamines and hydroxyalyklamines on 1,4 napthoquinones and the role of solvent on the position of substitution.

    Mahmood, TariqUniversity of Bradford2013

    … at either the 2- or 3-position. Although both regioisomers were produced in all the reactions, protic polar solvents favoured the formation of the 3-regioisomer, whereas non-protic solvents favoured the formation of the 2-regioisomer. It has also been found that formation of 2,3-diaminoalkyl …

    bradford Repository record

  2. Novel materials based on functionalised silsesquioxanes

    Hardy, JulieThe Open University2001

    … group at the allylic position producing the α-regioisomer as well as the typical β product. It is suggested that such substitution affects the mode of cis ligand insertion in the Chalk Harrod mechanism. A preference for the α-regioisomer was also observed for the hydrosilylations of vinyl …

    the-open-u Repository record

  3. Intramolecular [4+1] pyrroline annulation as a general method for the synthesis of pyrrolizidine alkaloids

    Frazier, James OwenVirginia Polytechnic Institute and State University1986

    … synthesis of the dienic azide system 1 and its regioisomer 2 by utilizing the vinylogous Reformatsky reaction, and the intramolecular additions of the azide moiety across the activated dienes with subsequent pyrolyses to provide the pyrrolizidines of type 3. This study broadened the scope of the …

    vt Repository record

  4. Synthetic Studies Towards the Crisamicins

    Lai, Michelle Yu HuayResearchSpace@Auckland2002

    … antibiotic crisamicin A 1.46 and its regioisomer 2.77. The synthetic strategy adopted is based on a double furofuran annulation/oxidative rearrangement strategy that has been successfully used by this research group to prepare a related dimeric pyranonaphthoquinone based on the …

    auckland-ms Repository record

  5. Novel Monomer Design for Next-Generation Step-Growth Polymers

    Wolfgang, Josh DavidVirginia Tech2021

    … and rheological properties. This unique pair of regioisomers allowed the tuning of the thermal and rheological properties for high glass transition temperature polyimides for engineering applications. The selection of the dianhydride regioisomer influenced the weight loss profile, entanglement …

    vt Repository record

  6. Structure-Property Relationships of Alicyclic Polyesters

    Thompson, Tiffany NikiaVirginia Tech2023

    … alicyclic polyesters using various ratios of two regioisomers of a previously unexplored alicyclic monomer, bicyclohexyldimethanol (BCD). We learned from this alicyclic polyester series that we could tailor properties such as morphology and elongation while raising the glass transition …

    vt Repository record

  7. Synthetic studies of ecteinascidin 743 and fennebricin B

    Le, Vy Hoang, author, Williams, Robert M., advisor, Kennan, Alan J., committee member, Finke, Richard G., committee member, Luger, Karolin, committee memberColorado State University. Libraries2017

    … the pentacylic core of Et-743 with the desired regioisomer as the only product. This approach was also utilized in the synthetic studies toward the total synthesis of fennebricin B.

    colostate Repository record

  8. The Biochemical Pathway Leading to Lpa Generation Upon Blood Coagulation

    Bolen, Alyssa Lynn Jefferson2016

    … LPAs in plasma. We next examined the regioisomeric preference of lysophospholipase D/autotaxin (ATX), which is the subsequent step in LPA production. To prevent acylmigration regioisomers of oleyl‑<em>sn</em>‑glycero‑3‑phosphocholine (LPAF) were synthesized. ATX preferred the …

    tenn-hsc Repository record

  9. Further investigations into the mechanism of the o-directed free radical hydrostannation of alkyl and aryl acetylenes

    Watson, HamishQueen's University Belfast2022

    … as well as their ability to affect the regioisomer outcome of this reaction. <br/><br/>Further to the experimental evidence we have also demonstrated the use of this new probe to allow for the determination of the relative rate constants involved in this reaction to show the different …

    qu-belfast Repository record

  10. En-Reaktion von Nitrosoaren, Triazolindion und Singulettsauerstoff

    Krebs, OliverUniversität Würzburg

    … für das twix- und twin-Regioisomer. Verantwortlich hierfür ist eine Koordination des Enophils durch Wasserstoffbrückenbindung in einem frühen Stadium der Reaktion, noch vor der Intermediatbildung. Für PTAD und ArNO wird auch die Regioselektivität durch den …

    wurz-thes Repository record

  11. Asymmetric synthesis involving silicon

    Xu, YouliThe Open University1996

    … by azide ion, leading exclusively to a single regioisomer. Similarly, the deoxygenation of vicinal silyl diols has been observed without loss of the silyl group. <br></br><br></br>Chiral analysis of trimethylsilyl amino alcohols and aziridines (with enantiomeric excesses of up to 95%) have been …

    the-open-u Repository record

  12. ΜΕΛΕΤΗ ΑΝΤΙΔΡΑΣΕΩΝ 1,3-ΔΙΠΟΛΙΚΗΣ ΚΥΚΛΟΠΡΟΣΘΗΚΗΣ ΣΕ ΕΤΕΡΟΚΥΚΛΙΚΑ ΣΥΣΤΗΜΑΤΑ

    Θεσσαλονικέως, ΕλισάβετΑριστοτέλειο Πανεπιστήμιο Θεσσαλονίκης (ΑΠΘ)1990

    … AND REGIOSELECTIVE, GIVING IN ALL CASES ONLY ONE REGIOISOMER, IN WHICH THE ANIONIC CENTER OF THE DIPOLE IS JOINED WITH THE TERTIARY CARBON ATOM OF OXAZOLONE-OR THIAZOLONE-RING. THE STRUCTURE OF THESE NEW COMPOUNDS WAS CONFIRMED BY SPECTROSCOPIC DATA AND BY CHEMICAL METHODS.THE OBSERVED …

    greece Repository record

  13. Fluorine-containing fullerenes and endometallofullerenes: synthesis, structure, and spectroscopic characterization

    Shustova, Natalia Borisovna, author, Strauss, Steven H., advisor, Anderson, Oren P., committee member, Szamel, Grzegorz, committee member, Elliott, Cecil Michael, committee member, Roess, Deborah A., committee memberColorado State University. Libraries2010

    … The first X-ray crystal structure of a single regioisomer of C59N(CF3)5, as well as spectroscopic studies of C59N(CF3)7,9,11, revealed unexpected addition patterns which resemble that of Cs-C60X6 derivatives. The isolation and characterization of seventeen Sc3N@(C80-Ih)(CF3)n (even n = 2-16) …

    colostate Repository record

  14. Reaktionen elektrophiler und nucleophiler Schwefeldonoren mit cyclischen Alkenen und Alkinen

    Fröhling, BettinaUniversität Würzburg

    … ein, bei der ausschließlich ein Regioisomer in 51 Prozent Ausbeute entsteht.

    wurz-thes Repository record

  15. Selective, nickel-catalyzed carbon-carbon bond-forming reactions of alkynes

    Miller, Karen M. (Karen Marie)Massachusetts Institute of Technology2005

    … an additive leads to formation of the opposite regioisomer in equal and opposite selectivity (5: >95). These results provide strong evidence for an interaction between the remote alkene and the metal center during the regioselectivity-determining step.

    mit Repository record

  16. Structure-Property Relationships of Polyester Regioisomers and Pendant Functionalized Polyetherimides

    Mondschein, Ryan JosephVirginia Tech2019

    … enabled the synthesis of novel polyester regioisomers and pendant functionalized polyetherimides (PEI)s. Novel monomers incorporated at targeted mol % produced series of polyesters and PEIs, suitable for systematic analysis of key polymer properties. Subsequent compositional, thermal, …

    vt Repository record

  17. Designing Functionality into Step-Growth Polymers from Liquid Crystallinity to Additive Manufacturing

    Heifferon, Katherine ValentineVirginia Tech2019

    … changes, such as exchanging a monomer for its regioisomer, affects the polymers fundamental packing structure triggering a domino effect ultimately influencing the morphological, thermal, mechanical and barrier properties. In conjunction, end groups provide a means by which tunable mechanical …

    vt Repository record

  18. Imidazole-Containing Polymerized Ionic Liquids for Emerging Applications: From Gene Delivery to Thermoplastic Elastomers

    Allen, Michael H. Jr.Virginia Tech2013

    … unstable N-vinyl propagating radical. The regioisomer 4-vinylimidazole (4VIM) contains two resonance structures affording increased radical stability of the propagating radical. Nitroxide-mediated polymerization (NMP) and atom transfer radical polymerization (ATRP) failed to control 4VIM …

    vt Repository record

  19. The role of PTEN as a PI(3,4)P2 lipid phosphatase in Class I phosphoinositide 3-kinase signalling

    Kielkowska, Anna JadwigaUniversity of Cambridge2018

    … PI(3,4)P2, separated from its more abundant regioisomer in cells - PI(4,5)P2. This and an existing HPLC-ESI MS/MS method for measuring PI(3,4,5)P3, have enabled us to describe the fluxes through Class I PI3K-controlled PI(3,4,5)P3 generation and its subsequent 3- and 5- dephosphorylation …

    cambridge Repository record

  20. Control of mechanochromic reactions in a polymer matrix

    Kim, TaeannUniversity of Illinois at Urbana-Champaign2018

    … effect is further studied for six NP regioisomers, each with different pulling points on the naphthalene ring. Computational simulations predict that only two regioisomers are mechanochromic. Tensile testing of polymers containing these two regioisomers confirmed mechanochemical …

    uiuc Repository record

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