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Davies, Clair. "Capillary Electrophoretic Separation of Sulfoxides." TopSCHOLAR®, 1998. http://digitalcommons.wku.edu/theses/338.
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Chiral sulfoxides are most widely used in asymmetric synthesis. Their application as chiral synthons has now become a well-established and reliable strategy, mainly due to availability and high asymmetric induction exerted by the chiral sulfinyl group. Very few articles have been published on the separation of chiral sulfoxides; most involve HPLC or GC. The first separation of optically active sulfoxides was described by Phillips and co-workers. To date no work has been reported using capillary electrophoresis for the separation of alkylaryl sulfoxides. A series of alkylaryl sulfoxides were synthesized. Conditions for their separation were investigated using a modified 125 mM Boric acid (pH 8.5)/ 75 mM SDS buffer solution (MEKC buffer). Synthetic procedures for the preparation of these sulfoxides will be presented as well as separation results. The separation is based on the differential partition of solutes between the micelle and the bulk solution.
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Kendall, Jackie D. "Synthesis and enantioselective transformations of sulfoxides." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311838.
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Grainger, Richard Sheridan. "Cycloaddition reactions of C2-symmetric vinyl sulfoxides." Thesis, University of Sheffield, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387754.
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Lee, Danny Ka Ming. "Unsaturated sulfinates and sulfoxides in organic synthesis." HKBU Institutional Repository, 1995. http://repository.hkbu.edu.hk/etd_ra/47.
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Rowen, Catherine Carmel, and n/a. "A New Approach Towards Bicyclo[4.2.0]octan-1-ols: Synthetic and Mechanistic Studies." Griffith University. School of Science, 2003. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20030602.131636.
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The reaction between the lithium enolate of cyclohexanone and phenyl vinyl sulfoxide resulted in the formation of the novel bicyclooctanol sulfoxides 215-217 and the monoalkylated sulfoxide 218. The effects of variation in reaction time, temperature and concentration were studied. Under optimal conditions (10 minutes, -10°C and 0.085 M) the ratio of the bicyclooctanol sulfoxides 215-217 (75% yield) to the monoalkylated sulfoxide 218 was 95:5. The bicyclooctanol sulfoxides 215-217 were characterised as the sulfone derivatives, bicyclooctanol sulfones 219 and 220. X-ray crystal structures were used to determine the relative stereochemistry of the bicyclooctanol sulfoxides 215-217 and the bicyclooctanol sulfones 219 and 220. Bicyclo[4.2.0]octano-1-ol formation was determined to occur via an ionic mechanism. Mechanistic studies were carried out using variations in reaction lighting and reaction solvent, conducting the reaction in the presence of a radical trap and quenching the reaction with a deuterium label. The role of the counterion was determined to be important in the formation of the bicyclooctanol sulfoxides 215-217. Sequestering lithium ions with HMPA and substituting lithium with potassium favoured alkylation. Substituting the lithium enolate of cyclohexanone with the dimethylaluminium enolate of cyclohexanone resulted in a different distribution of the bicyclooctanol sulfoxides 215-217 and the formation of bicyclooctanol sulfoxide 243. Transition states to account for these differences have been proposed. The stability of the bicyclooctanol sulfoxides under conditions of acid, base and heating was studied. Thermal ring opening of the bicyclooctanol sulfoxides 215 and 216 to the monoalkylated sulfoxides 218A and 218B respectively occurred with retention of the configuration at sulfur. The relative stereochemistry of the individual bicyclooctanol sulfoxides 215-217 was considered to account for the observed stability in each case. The reaction between the lithium enolate of cyclohexanone and (R)-(+)-p-tolyl vinyl sulfoxide 193 gave the bicyclooctanol tolyl sulfoxides 246, 251 and 252 and the monoalkylated tolyl sulfoxide 247. This showed that both bond rotation in the side chain of the intermediate and epimerisation at sulfur occurred in the bicyclo[4.2.0]octan-1-ol forming process. The presence of the sulfoxide functionality in phenyl vinyl sulfoxide was determined to be crucial to the formation of bicyclo[4.2.0]octan-1-ols. In the reaction with the lithium enolate of cyclohexanone, phenyl vinyl sulfide gave no reaction, phenyl vinyl sulfone gave the bicyclic disulfones 260-265, ethyl acrylate gave the diesters 266-268 and diphenylvinylphosphine oxide gave the phosphine oxide 269. The cyclobutanol 270 and the ketone 271 were the products resulting from the reaction between the reaction between the lithium enolate of acetophenone and phenyl vinyl sulfoxide. This demonstrated potential scope for the cyclisation process using both cyclic and acyclic ketones.
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Rowen, Catherine Carmel. "A New Approach Towards Bicyclo[4.2.0]octan-1-ols: Synthetic and Mechanistic Studies." Thesis, Griffith University, 2003. http://hdl.handle.net/10072/367745.
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The reaction between the lithium enolate of cyclohexanone and phenyl vinyl sulfoxide resulted in the formation of the novel bicyclooctanol sulfoxides 215-217 and the monoalkylated sulfoxide 218. The effects of variation in reaction time, temperature and concentration were studied. Under optimal conditions (10 minutes, -10°C and 0.085 M) the ratio of the bicyclooctanol sulfoxides 215-217 (75% yield) to the monoalkylated sulfoxide 218 was 95:5. The bicyclooctanol sulfoxides 215-217 were characterised as the sulfone derivatives, bicyclooctanol sulfones 219 and 220. X-ray crystal structures were used to determine the relative stereochemistry of the bicyclooctanol sulfoxides 215-217 and the bicyclooctanol sulfones 219 and 220. Bicyclo[4.2.0]octano-1-ol formation was determined to occur via an ionic mechanism. Mechanistic studies were carried out using variations in reaction lighting and reaction solvent, conducting the reaction in the presence of a radical trap and quenching the reaction with a deuterium label. The role of the counterion was determined to be important in the formation of the bicyclooctanol sulfoxides 215-217. Sequestering lithium ions with HMPA and substituting lithium with potassium favoured alkylation. Substituting the lithium enolate of cyclohexanone with the dimethylaluminium enolate of cyclohexanone resulted in a different distribution of the bicyclooctanol sulfoxides 215-217 and the formation of bicyclooctanol sulfoxide 243. Transition states to account for these differences have been proposed. The stability of the bicyclooctanol sulfoxides under conditions of acid, base and heating was studied. Thermal ring opening of the bicyclooctanol sulfoxides 215 and 216 to the monoalkylated sulfoxides 218A and 218B respectively occurred with retention of the configuration at sulfur. The relative stereochemistry of the individual bicyclooctanol sulfoxides 215-217 was considered to account for the observed stability in each case. The reaction between the lithium enolate of cyclohexanone and (R)-(+)-p-tolyl vinyl sulfoxide 193 gave the bicyclooctanol tolyl sulfoxides 246, 251 and 252 and the monoalkylated tolyl sulfoxide 247. This showed that both bond rotation in the side chain of the intermediate and epimerisation at sulfur occurred in the bicyclo[4.2.0]octan-1-ol forming process. The presence of the sulfoxide functionality in phenyl vinyl sulfoxide was determined to be crucial to the formation of bicyclo[4.2.0]octan-1-ols. In the reaction with the lithium enolate of cyclohexanone, phenyl vinyl sulfide gave no reaction, phenyl vinyl sulfone gave the bicyclic disulfones 260-265, ethyl acrylate gave the diesters 266-268 and diphenylvinylphosphine oxide gave the phosphine oxide 269. The cyclobutanol 270 and the ketone 271 were the products resulting from the reaction between the reaction between the lithium enolate of acetophenone and phenyl vinyl sulfoxide. This demonstrated potential scope for the cyclisation process using both cyclic and acyclic ketones.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
Faculty of Science
School of Science
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Heer, Jag Paul. "New methods of asymmetric oxidation." Thesis, University of Liverpool, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484195.
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Chan, Eddy Tsz Tak. "Unsaturated sulfoxides in organic synthesis : a new furan synthesis and total synthesis of isoquinolone alkaloids." HKBU Institutional Repository, 1991. https://repository.hkbu.edu.hk/etd_ra/3.
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Banjavciªc, Marko Peter. "Infrared multiple-photon dissociation of small organic sulfoxides." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0020/NQ41366.pdf.
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Motto, John M. "Ã,ß-unsaturated sulfoxides and sulfinic acid derivatives." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/MQ58363.pdf.
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Snyder, Chad. "Enantioseparation of Alkylaryl Sulfoxides Using Capillary Zone Electrophoresis." TopSCHOLAR®, 1999. https://digitalcommons.wku.edu/theses/3040.
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Alkylaryl sulfoxides possess a chiral sulfur atom easily identifiable by capillary zone electrophoresis (CZE). Separation of chiral alkylaryl sulfoxides has already been accomplished by modified method of CZE known as micellar electrokinetic chromatography (MEKC). However, no articles have been published on the enantioseparation of alkylaryl sulfoxides using capillary zone electrophoresis.
A series of sulfoxides were synthesized, purified and identified via NMR. Enantioseparation was performed using CZE employing a 10 mmol. Phosphate buffer (pH 4.0, 25% acetonitrile, 2% sulfated-β-cyclodextrin). Synthesis of these sulfoxides will be presented along with the results of the procedure’s optimization. Separation of the sulfoxide enanitomers relies on the partitioning between the chiral additive (sulfated-β-cyclodextrin) and buffer solution.
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Jog, Parag V. "Sulfoxides as an intramolecular sulfenylating agent for indoles and diverse applications of the sulfide-sulfoxide redox cycle in organic chemistry /." Available online. Click here, 2005. http://sunshine.lib.mtu.edu/ETD/DISS/jogp/diss.pdf.
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Balcells, Badia David. "A Computational Approach to the Synthesis of Chiral Sulfoxides." Doctoral thesis, Universitat Autònoma de Barcelona, 2006. http://hdl.handle.net/10803/3225.
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La síntesi de sulfòxids quirals ha estat investigada teòricament considerant dos dels mètodes més avançats: l'oxidació asimètrica de sulfurs amb peròxid d'hidrogen catalitzada per vanadi i el mètode DAG. El mecanisme d'aquestes reaccions va ser explorat a nivell DFT (teoria del funcional de la densitat) en sistemes models. L'origen de l'enantioselectivitat en els sistemes reals va ser investigat emprant mètodes híbrids QM/MM (mecànica quàntica/mecànica molecular). L'estudi DFT sobre la sulfoxidació asimètrica catalitzada per vanadi va revelar que aquest procés segueix un mecanisme de transferencia directa d'oxigen en que el substrat s'oxida en una única etapa concertada. El catalitzador és un complex de vanadi(+V) en que l'oxidant es coordina al metall en mode hidroperoxo. Aquest complex catalitza el procés d'oxidació reduint la barrera energètica de 40.4 a 26.7 kcal/mol. L'estudi QM/MM del sistema real va demostrar que existiexen dos diastereòmers del catalitzador, etiquetats com a A i B, que catalitzen l'oxidació induint enantioselectivitats oposades. La coexistencia d'A i B en solució va permetre racionalitzar l'influència de l'estructura del lligand quiral sobre l'enantioselectivitat. L'estudi DFT del mètode DAG va revelar que la resolució cinètica dinàmica implicada en aquesta reacció segueix un mecanisme d'addició/eliminació. L'etapa clau és l'addició en que l'alcohol reacciona directament amb el clorur de sulfinil. Aquest procés implica un transferència d'hidrogen que és assistida per una base. La trimetilamina redueix la barrera d'aquest procés desde 26.8 a 12.2 kcal/mol. La base també catalitza la racemització del clorur de sulfinil reduint la barrera de la seva inversió piramidal desde 63.4 a 22.3 kcal/mol. La subsititució inicial del clor per la base va ser descartada. L'estudi QM/MM del sistem real confirmà que l'enantioselectivitat d'aquest procés es pot invertir amb facilitat emprant diferents bases no quirals, com la piridina o la colidina, tal com va ser observat experimentalment. El nostre estudi revelà que el paper estèric de la base és fonamental quan la piridina es canvia per colidina. Aquest canvi de base implica una inversió de la distribució quiral del volum estèric al voltant del sofre que provoca el canvi en el sentit de l'enantioselectivitat.The synthesis of chiral sulfoxides has been theoretically investigated considering two of the most advanced methods: the vanadium-catalyzed asymmetric oxidation of sulfides with hydrogen peroxide and the DAG method. The mechanism of these reactions was explored at a DFT (Density Functional Theory) level on model systems. The origin of enantioselectivity in the real systems was explored applying hybrid QM/MM (Quantum Mechanics/Molecular Mechanics) methods. The DFT study on the vanadium-catalyzed asymmetric sulfoxidation revealed that this process follows a direct oxygen transfer mechanism in which the substrate is oxidized in a single concerted step. The catalyst is a oxo complex of vanadium(+V) with the oxidant coordinated to the metal as a hydroperoxo ligand. This complex catalyzes the oxidation process reducing the energy barrier from 40.4 to 26.7 kcal/mol. The QM/MM study on the real system showed that there are two possible diastereomers of the catalyst, labeled as A and B, that catalyze the oxidation inducing opposite enantioselectivities. The coexistence of A and B in solution explains the influence of the chiral ligand structure upon enantioselectivity. The DFT study on the DAG method revealed that the dynamic kinetic resolution involved in this transformation follows an addition/elimination mechanism. The key step is the addition in which the alcohol reacts directly with the sulfinyl chloride. This process implies a hydrogen transfer assisted by the base. Triethylamine reduces the barrier of this process from 26.8 to 12.2 kcal/mol. The base also catalyzes the racemization of the sulfinyl chloride reducing the barrier of its pyramidal inversion from 63.4 to 22.3 kcal/mol. The substitution of chlorine by the base was discarded. The QM/MM study of the real system confirmed that the enantioselectivity of this reaction can be easily reversed using different non chiral bases, like pyridine or collidine, as experimentally observed. Our study showed that the steric role of the base becomes critical when pyridine is replaced by collidine. This modification of the base implies an inversion of the chiral distribution of steric bulk around sufur that induces the reversal of enantioselectivity.
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Xie, Ning. "Lewis acid catalyzed oxidation of sulfides and sulfoxides by permanganate." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/nq35823.pdf.
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Jing, Lin. "Chiral Ý-amino sulfoxides and chiral sultams in asymmetric synthesis." HKBU Institutional Repository, 2000. http://repository.hkbu.edu.hk/etd_ra/261.
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Kennedy, Martina Anne. "Production and application of dioxygenase-catalysed oxidation products from alkenes, arenes and thiaarenes." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301720.
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Paylor, Michael Mark. "Biotransformation of organosulfides with the bacterium Rhodococcus rhodochrous ATCC 19067." Thesis, University of Exeter, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245300.
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Raza, Muhammad Rehail. "Synthesis and chemistry of novel chiral sulfilimines." Thesis, Keele University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311151.
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Yoshikawa, Eduardo Kunio Chinone. "Estudos da Decomposição Térmica de Alguns Sulfóxidos -Funcionalizados." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-04122014-113343/.
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A decomposição térmica dos compostos sulfoxídicos (1)-(4) foi efetuada a ca. 140 °C, até conversão total do material de partida. A mistura de produtos resultante, em cada caso, foi analisada por cromatografia gasosa/espectrometria de massas. Foram preparadas amostras autênticas dos compostos assim identificados e, no caso dos sulfóxidos (2)-(4), a composição do produto de termólise foi determinada através de análises por cromatografia gasosa e RMN de 1H, utilizando-se o método do padrão interno. Os resultados obtidos estão sumarizados abaixo: Tabela - ver arquivo em PDF - Para três dos substratos estudados, os produtos finais poderiam originar-se de hemitiocetais intermediários, formados por um rearranjo de Pummerer. Este mecanismo de decomposição parece ser geral para sulfóxidos β-carbonílicos. No entanto, o substrato (1) decompõe-se termicamente por mecanismo radicalar.The thermal decomposition of sulfoxides (1)-(4) was performed at ca. 140 °C, until complete consumption of the starting materiais. In each case, the product mixture was analyzed by GC/MS. Authentic samples of identified components were prepared, and in the case of sulfoxides (2)-(4), the crude product composition was determinded by gas chromatography and 1H NMR analyses (internal standard method).Results are as follows: See chart PDF file - For three cases, final products could originate from intermediate hemithioacetals, generated via a thermal Pummerer rearrangement. lhis decomposition mechanism seems to be general for the thermolysis of β-carbonyl sulfoxides. However, sulfoxide (1) decomposes under heating via a radical mechanism.
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Boone, Kenneth P. "Photodissociation of (DMSO)₂Fe(II)TPP, (TMSO)₂Fe(II)TPP, and (PSO)₂Fe(II)TPP to form a transient five-coordinate complex as studied using transient resonance Raman spectroscopy /." Connect to full text in OhioLINK ETD Center, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=toledo1229660779.
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Thesis (M.S.)--University of Toledo, 2008.Typescript. "Submitted as partial fulfillment of the requirements for the Master of Science Degree in Chemistry." "A thesis entitled"--at head of title. Bibliography: leaves 58-62.
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Lam, Kwun Ting. "Chiral acetylenic sulfoxide in asymmetric alkaloid synthesis." HKBU Institutional Repository, 2004. http://repository.hkbu.edu.hk/etd_ra/509.
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Zhang, Yu-Feng. "Selective Electrocatalytic reduction mediated by Sm(II) : Application to nitroarenes, sulfoxides and phthalimides." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS596/document.
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Le SmI₂ en tant que réactif de transfert monoélectronique a été largement utilisé en chimie organique depuis les premiers travaux de Kagan. Cependant, la quantité stœchiométrique ou en excès de SmI₂ et d'additifs toxique tels que HMPA sont utilisés normalement pour améliorer la réactivité. De plus, à cause de sa sensibilité à l'oxygène, le stockage de la solution de SmI₂ dans le THF est difficile. Récemment, nous avons développé une nouvelle méthode électrocatalytique basée sur la régénération électrochimique de Sm²⁺. Par rapport à la réactivité du SmI₂ classique, notre approche utilise une quantité catalytique de Sm. Premièrement, pour la réduction de nitroarènes, la réaction a sélectivement fourni les composés aromatiques azoïques et les anilines en fonction du solvant choisi. Notamment, c'est la première fois que la réaction Sm²⁺ se produit dans le méthanol dans le cas des anilines. Deuxièmement, dans le cas de la réduction des sulfoxydes par SmI₂, en général, l'HMPA était nécessaire comme additif. Dans notre procédé électrocatalytique, les sulfoxydes ont été transformés en sulfures avec une chimiosélectivité élevée et des excellents rendements toujours à température ambiante sans besoin ni de HMPA ni d’atmosphère protectrice. Enfin, les dérivés d'isoindolinone sont des séries de produits importants en chimie organique, la réduction des phtalimides est l'approche la plus pratique pour les obtenir. Avec les alcools, l'alcoxylation réductrice de phtalimides a eu lieu pour la première fois avec le Sm²⁺ électrocatalytique dans nos conditions. Et si on ajoute d'autres sources de protons, ce procédé a fourni les ω-hydroxylactames et isoindolinones correspondants avec des rendements élevésThe SmI₂ as a single electron transfer reagent has been widely used in organic chemistry since the pioneering works by Kagan. However, the stoichiometric or excess amount of SmI₂ and harmful additives such as HMPA are used normally to enhance the reactivity, moreover, due to the oxygen sensitive, the storage of SmI₂ solution is difficult.Recently, we have developed a new electrocatalytic method based on the electrochemical regeneration of Sm²⁺. Compared to the classic SmI₂ reaction, our process occurred with a catalytic amount of Sm. In the reduction of nitroarenes, it selectively afforded the azo aromatic compounds and anilines depending on different solvents system. Notably, it’s the first time that the Sm²⁺ reaction occurred in the methanol. Normally, the HMPA was the additive in the reduction of sulfoxides by SmI₂. Under our electrocatalytic process, the sulfoxides were converted into sulfides in high chemoselectivity and yield at room temperature without HMPA and protecting atmosphere.The isoindolinone derivatives are series of important products in organic chemistry, the reduction of phthalimides is the most convenient approach to provide them. With alcohols, the unprecedented Sm²⁺ electrocatalyzed reductive alkoxylation of phthalimides was established. Moreover, adding other proton sources, this process afforded the corresponding ω-hydroxylactams and isoindolinones
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Mo, Tian. "Chiral acetylenic sulfoxide in asymmetric synthesis ; Enantioselective synthesis of yohimbine alkaloids." HKBU Institutional Repository, 1997. http://repository.hkbu.edu.hk/etd_ra/158.
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Strickler, Ricky R. "Sulfinyl chlorides as a source of enantioenriched Ã,ß-unsaturated sulfinate esters and sulfoxides." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ56296.pdf.
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Biaggio, Francisco Carlos. "Estudos de sulfenilação de alguns sulfóxidos funcionalizados. Reações de pummerer, catalisada e térmica, de β-ceto, α-metiltio sulfóxidos." Universidade de São Paulo, 1993. http://www.teses.usp.br/teses/disponiveis/46/46135/tde-22062015-104405/.
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A finalidade deste trabalho é o estudo de reações de carbânions de sulfóxidos funcionalizados com reagentes sulfenilantes, pelo emprego de dois métodos: fase homogênea e transferência de fases. A revisão bibliográfica apresentada demonstra que trata-se de reações novas e que, entretanto, outras reações de carbânions de sulfóxidos funcionalizados, tais como alquilações, acilações, condensações com compostos carbonílicos e adições de Michael, já tinham sido descritas. Por outro lado, poucas reações de sulfinil carbânions tinham sido efetuadas pelo emprego do método de transferência de fases. As reações de sulfenilação em fase homogênea de α-sulfinil cetonas aromáticas (Ia-d), e cíclicas (II), α-sulfinil ésteres (IIIa,b) e tioéster (IV) foram efetuadas pelo emprego de NaH/DMSO e de dimetildissulfeto ou metanotiossulfonato de metila (MeSO2SMe). Com exceção do composto (IIIb) que não reagiu, em todos os casos foram obtidos compostos monossulfenilados ainda não descritos na literatura. Os rendimentos variavam entre 25-90%, na ordem: Ib > Ia > IVa > Ic > Id > IIIa > II. As reações de sulfenilação em transferência de fases foram efetuadas pelo emprego de dois procedimentos distintos: o de extração do íon-par (A) e o sistema Sólido-líquido (B). Os compostos Ia, IIIa e IVb foram submetidos à sulfenilação pelo procedimento A, em que usou-se NaOH/CH2Cl2/Bu4NHSO4 e MeSO2SMe. Enquanto Ia e IIIa renderam produtos monossulfenilados em baixos rendimentos, IVb não reagiu. As reações de sulfenilação pelo procedimento B, usando-se K2CO3/ΦH/TEBA e MeSO2SMe foram efetuadas com os compostos Ia-d, IIIa e IVb e mostraram-se mais satisfatórias do que pelo procedimento A, pois todos reagiram, rendendo produtos monossulfenilados. O rendimento do composto IIIa era apenas de 20% , mas os rendimentos dos outros derivados variavam entre 40-67%. Observou-se, através da análise de RMN-1H, em todos os derivados sulfenilados, a presença de dois diastereoisômeros em quantidades iguais. Entretanto, substituindo-se o TEBA por um sal de quinínio quirálico, no caso de duas sulfinil cetonas (Ia e Ic) os compostos sulfenilados correspondentes mostraram uma relação diastereomérica de 4:1. O trabalho apresenta também os resultados de decomposição térmica de sulfinil cetonas monossulfeniladas, efetuado com a finalidade de investigar a aplicabilidade sintética destes compostos. A obtenção de α-cetotioésteres é interpretada como uma reação de Pummerer não catalisada e se constitui em um método alternativo de preparação destes compostos. A decomposição térmica de sulfinil cetonas não sulfeniladas, efetuada para fins de comparação, mostrou-se mais complexa e de difícil interpretação.The scope of this work consists of a study of reactions of carbanions of functionalyzed sulfoxides with sulfenylating reagents, employing two methods: in the homogeneous phase and by the phase transfer. The literature review, which is presented, shows that although these reactions are new, some other reactions of the carbanions of the functionalyzed sulfoxides, such as alkylations, acylations, condensations with carbonyl compounds and Michael addition, have been already reported. Furthermore, a small number of reactions of sulfinyl carbanions by phase transfer method has been described. The sulfenylation reaction, in the homogeneous phase of the α-sulfinyl aromatic (Ia-d) and cyclic (II) ketones, α-sulfinyl esters (IIIa,b) and thioesters (IVa,b) were performed employing NAH/DMSO and dimethyldissulfide or methyl methanethiosulfonate (MeSO2SMe). Except for the compound (IIb), which showed to be unreactive, in all other cases the monosulfenylated derivatives, not reported previously in the literature, were obtained. The yields of these compounds of 25-90% follow the order: Ib > Ia > IVa > Ic > Id > IIIa > II. The sulfenylation reactions by the phase transfer method were performed employing two different procedures: ion-pair extraction (A) and solid-liquid system (8). The procedure (A) was applied to the compounds Ia, IIIa and IVb, using NaOH/CH2Cl2/Bu4NHSO4 and MeS02SMe. While Ia and IIIa yielded the monosulfenylated derivatives in good yields, IVb remained unchanged. The sulfenylation reactions by procedure (B), using K2CO3/ΦH/TEBA and MeSO2SMe, carried out with the compounds Ia-d, IIIa and IVb, showed to be more satisfactory than by procedure (A), as all compounds afforded the monosulfenylated derivatives. The yield of compound IIIa was only of 20%, but those for other compounds were of 40-67%. The 1H-NMR analysis of the sulfenylated derivatives showed the presence of two diastereomers in equal quantities. It was possible, by replacement of TEBA by a quiral quininium salt, for the case of two sulfinyl ketones (Ia and Ic), to obtain the corresponding sulfenylated derivatives of diastereomeric ratio 4:1. This work presents also, having in application, the thermal decomposition monosulfenylated sulfinyl ketones. The mind the synthetic reaction of the obtention of the α-ketothioesters is interpreted as a non catalyzed Pummerer reaction and may be considered as an alternative method for preparation of these compounds. The thermal decomposition of the non-sulfenylated sulfinyl ketones performed for comparison, showed to be more complex and hardly to be interpreted.
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Price, David Wilfred. "Directed hydrogenation of sulphoxides and sulphones." Thesis, University of Oxford, 1992. http://ora.ox.ac.uk/objects/uuid:725ef76d-0cc3-4b6c-afa4-ff95f078b6da.
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This thesis describes the synthesis of a number of hydroxy vinylsulphoxides and sulphones by a high pressure modification of the Baylis-Hillman reaction, together with their directed hydrogenation catalysed by rhodium catalysts. A detailed kinetic analysis of a number of the hydrogenation reactions carried out by numerical analysis is also presented. Chapter 1 serves as an introduction to directed hydrogenation and the chemistry of sulphur containing compounds. Chapter 2 details the synthesis of catalysts and substrates used in hydrogenation reactions. The use of high pressures to improve the performance of the Baylis-Hillman reaction is included. Chapter 3 details the products and the selectivity obtained in the hydrogenation of hydroxy vinylsulphoxides and sulphones. The kinetic resolution of 3-phenyl-2-(phenylsulphonyl)- propene-3-ol using a DiPAMP rhodium catalyst is described. Chapter 4 details the numerical analysis of the kinetics of the hydrogenation reactions of a number of hydroxy vinylsulphoxides and sulphones.
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Beecher, Jean Elizabeth. "Sulfoxidation by microbial monooxygenases." Thesis, University of Exeter, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244958.
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Ho, King Fai. "Solid-phase organic synthesis of sulfoxide and chemistry of Ü, Ý-unsaturated-Þ-sultam." HKBU Institutional Repository, 2000. http://repository.hkbu.edu.hk/etd_ra/366.
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Vahedi, Hooshang. "Catalytic symmetric oxidation of sulfides to sulfoxides mediated by 3-substituted-1,2-benzisothiazole 1,1-dioxides." Thesis, University of Liverpool, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.367257.
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Kentish, Barnes William. "[2,3]-Stevens rearrangement of vinyl aziridines : the use of sulfoxides as Lewis bases in allylations." Thesis, University of Sussex, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270559.
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Soltau, Carl Peter. "Nitroxide trapping of radical species formed from the reaction of sulfoxides with reactive oxygen species." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/210339/1/Carl_Soltau_Thesis.pdf.
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This project focussed on an in-depth evaluation of an established methodology that uses dimethyl sulfoxide (DMSO) as a reactive solvent with a profluorescent nitroxide (PFN) to detect and quantify particulate matter-derived ROS (Reactive Oxygen Species). Additionally, a novel approach which utilized cyclic sulfoxide tetrahydrothiophene-1-oxide (THTO) as the reactive solvent was investigated. The reactions of these sulfoxides with ROS generated from multiple sources in the presence of nitroxide radical scavengers were investigated. The results of these experiments show that nitroxides can display much broader reactivity than the simple radical scavenging processes that have previously been accepted.
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Thaler, Tobias. "Enantiocontrol with Chiral Sulfoxides and Diastereocontrol in the Cross-Couplings of Substituted Cycloalkyl and Piperidinyl Derivatives." Diss., lmu, 2011. http://nbn-resolving.de/urn:nbn:de:bvb:19-134189.
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Feizabad, Mohammad Sadegh [Verfasser], and Michael [Akademischer Betreuer] Keusgen. "Synthesis of cysteine sulfoxides and related compounds occurring in wild onions / Mohammad Sadegh Feizabad ; Betreuer: Michael Keusgen." Marburg : Philipps-Universität Marburg, 2019. http://d-nb.info/1198401540/34.
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Ben, Robert N. "Part~A. Lithiated bicyclic sulfoxides. Part~B. The synthesis of optically active alpha-amino esters via kinetic dynamic resolution." Thesis, University of Ottawa (Canada), 1995. http://hdl.handle.net/10393/10122.
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Part A. Lithiated bicyclic sulfoxides. The stereochemistry of the reaction of the lithio derivatives of two sets of isomeric 3-thia (3.2.1) octane-3-oxides with electophiles such as benzyl bromide, acetone and D$\sb2$O has been studied. Introduction of the deuterium always occurred cis to the S=O bond as expected on the basis of earlier results described by Marquet for the related thiane-S-oxides. In contrast, benzyl groups were introduced either cis or trans to the existing S=O bond. The results are most readily rationalized in terms of a planar configuration at the $\alpha$-carbanion center. The unexpected cis benzylations are due to steric hindrance of the preferred approach anti to the S=O bond by either the ethano bridge or the 8-endo methyl group. Part B. The synthesis of optically active $\alpha$-amino esters via kinetic dynamic resolution. The synthesis of N-protected optically active $\alpha$-amino esters from racemic $\alpha$-halo esters via kinetic dynamic resolution will be described. This methodology is general in nature and provides the desired optically active N-protected amino esters in 70-95% yield with diastereomeric excesses in the range of 85 to $>$98%. Applications and mechanistic aspects of the reaction will be discussed.
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ANDRUSKI, STEPHEN WALTER. "I. GEOMETRIC EFFECTS IN SULFUR LONE-PAIR INTERACTIONS. II. SYNTHETIC USES OF SULFOXIMINES, SULFOXIDES AND HEMITHIOKETALS WITH STEREOCHEMICAL CONTROL." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184042.
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An X-ray crystal analysis of l,8-Bis(methylthio)naphthalene (1.1) revealed that the molecule has a geometry in which the naphthalene ring is twisted to place the 1,8- substituents symmetrically above and below the naphthalene plane. The methyl groups are rotated out of the naphthalene plane. X-ray crystal analysis of Naphtho [1, 8-b, c] -1, 5- dithiocin (1.2) showed that naphthalene ring is twisted as in 1.1, however the disposition of the sulfurs above and below the plane is unsymmetrical. The aliphatic portion of the molecule is in a chair-like conformation. Comparison of these two structures indicates that the bond asymmetry across the naphthalene ring is due largely to bond stretching to relieve steric overcrowding. MNDO calculations on 1.1 and 1.2 give HOMO's which are predominantly naphthalene in character. Our MNDO eigenvalues for 1.1 and naphtho[l,8-d,e]-l,3-dithiin (2.1) correlate well with their PES ionization potentials. We predict an ionization potential of -7.60-7.76eV for 1.2. Reduction of the ethylene hemithioketal of norcamphor is shown to proceed with heterolysis of the carbon-oxygen bond and hydride attack on the resulting thionium ion occurring from the sterically less hindered exo face of the norbornane moiety. The stereochemistry of the resulting substituted norbornanes (3.4 and 3.5) is proved to be endo. In the reduction of N-phthalimido sulfoximines to sulfoxides with hydrazine in ethanol, a species is formed which gives reduction of certain unsaturated compounds. The reducing species is shown not to be diimide. Formation of 1,1-diazene is a possible explanation for the experimental results. The cycloaddition of (±)-S-2'-thienyl-S-vinyl-Nphthalimidosulfoximine ((±)-5.1g) with cyclopentadiene proceeds in good yield, however asymmetric induction in the resulting adducts is negligible. This strongly indicates that steric factors are controlling the asymmetric induction in this cycloaddition. (±)-Thiochromone-l-oxide (±)-5.8) and (±)-N-phthalimido-l-imino-4-thiochromone-l-oxide (±)- 5.6) are shown to undergo Diels-Alder reactions with cyclopentadiene in good yields giving only endo products with good diastereoselectivity. The diastereoselectivity of the reaction of (±)-5.8 with cyclopentadiene is shown to increase when the reaction is run at -78° with AlCl₃ as a catalyst. These results can be interpreted on the basis of approach of the diene on the less hindered face of the more reactive conformer.
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Akinnusi, Taiwo Kayode. "Studies on the stereoselective synthesis of the C17 backbone of the Alternaria toxins using chiral sulfoxide methodology." Diss., Access to E-Thesis, 2000. http://upetd.up.ac.za/thesis/available/etd-03272006-120628/.
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El-Rjoob, Abdul-Wahab. "Dynamic stationary phase modification in reversed-phase high performance liquid chromatography /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9720536.
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Thaler, Tobias Johannes Werner [Verfasser], and Paul [Akademischer Betreuer] Knochel. "Enantiocontrol with Chiral Sulfoxides and Diastereocontrol in the Cross-Couplings of Substituted Cycloalkyl and Piperidinyl Derivatives / Tobias Thaler. Betreuer: Paul Knochel." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2011. http://d-nb.info/1015170943/34.
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Saikaley, Amanda. "I. Preparation of β-amino Sulfoxides as Potential Selective Connexin Inhibitors II. Synthesis of Isoxylitone Analogues for the Treatment of Epilepsy." Thesis, Université d'Ottawa / University of Ottawa, 2015. http://hdl.handle.net/10393/33424.
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Part I. Preparation of β-amino sulfoxides as potential selective connexin inhibitors
Intercellular communication is the basis for the development and homeostasis of tissues and multicellular organisms, influencing functions such as regulation of growth, cell differentiation, and developmental signalling. The connexins are a family of integral membrane proteins that oligomerize into clusters of intercellular channels that connect the cytoplasm of neighbouring cells, allowing gap junction intercellular communication (GJIC). In particular, hemi-channels remain closed to avoid dissolution of ionic gradients and leakage of cytoplasmic constituents, whereas conditions of anoxia provoke the opening of these hemi-channels, often leading to cell death. Thus far, a compound code named AF101 possesses the greatest amount of selectivity and inhibition of GJIC. A series of nearly twenty β-amino sulfoxides using AF102 as the lead structure were prepared by introducing various new substituents to the three aromatic rings on the molecule and by changing the aryl subtituents at the sulfoxide moiety. In each example, the diastereomers were separated and the relative configuration at carbon and sulfur was assigned via 1H NMR. The amino sulfoxides were subsequently transformed into amino sulfones and amino sulfides via oxidation and reduction reactions, respectively. We are awaiting the results of the bioassays of all of these compounds. The results will determine if any of them show selective altering of connexin activity.
Part II. Synthesis of Isoxylitone analogues for the treatment of epilepsy.
Epilepsy is a chronic disorder of the brain that affects roughly 50 million people worldwide. Extracts of a variety of plants have been used for many years to treat a number of neurological disorders. Delphinium denudatum Wall has been used to treat seizures by local folk medicine practitioners and a bioassay guided fractionation identified the active component as isoxylitone, also referred to as ISOX. Thirty five compound analogues were prepared starting from readily available isophorone [3,5,5, trimethylcyclohex – 2- ene -1one] and other cyclohexenones. Compound 16 possesses the highest activity by inhibiting epileptic seizures in rats by 65% at a concentration of 200 nM. This compound has been further investigated and widely studied in a variety of other in vitro and in vivo models. The E/Z mixture of the ethyl ester 4 also showed promising activity. The Z isomer of 4 and its methyl ester analogue 8, were prepared by reacting the potassium salt of the pure Z acid 7Z with Et3I and CH3I respectively. These Z isomers were less potent than the mixture, indicating that most of the activity resides in the E isomer. Recrystallization of 16 from hexanes afforded the E isomer in 92% purity. Surprisingly, this isomer was less active than the E/Z mixture of 16.
Esterification of 7Z in acidic MeOH or EtOH afforded the same E/Z mixture of esters obtained in the initial synthesis. This indicates that a rapid isomerization under acidic conditions. In contrast, 16E remained unchanged upon heating in MeOH containing a catalytic amount of HCl or PTSA over a period of 8 hours.
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Niyama, Emy. "Complexos de dibenzoilmetanatos de terras raras com ligantes R2S=O utilizados como emissores em dispositivos eletroluminescentes." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/46/46134/tde-26112008-101833/.
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Este trabalho apresenta a síntese e os estudos foto e eletroluminescentes dos complexos de β-dicetonatos (dibenzoilmetanato -DBM) de terras raras trivalentes (TR=Eu3+, Sm3+ e Gd3+) hidratados e contendo ligantes sulfóxidos (L= dibenzilsulfóxido - DBSO, dimetisulfóxido - DMSO, difenilsulfóxido - DPSO e p-toluilsulfóxido - PTSO). Os complexos obtidos foram caracterizados através das seguintes técnicas: i) análise elementar de carbono e hidrogênio; ii) análise dos íons TR3+ por titulação complexométrica; iii) difração de Raios X (método do pó); iv) análise térmica; v) espectroscopia vibracional de absorção no infravermelho (IV); e vi) microscopia eletrônica de varredura (MEV). As curvas TG/DTG dos complexos [TR(DBM)3H2O] e [TR(DBM)3(L)2] apresentam as etapas de decomposição térmica bem definidas e indicam que os complexos com ligantes sulfóxidos apresentam maior estabilidade térmica que os hidratados. Os espectros de absorção na região do IV evidenciam que a coordenação dos ligantes orgânicos (DBM e sulfóxidos) ao íon TR3+ ocorre através dos átomos de oxigênio. As fotomicrografias dos filmes indicam que as técnicas de deposição de filmes a vácuo e em solução podem fornecer filmes de boa qualidade. Os difratogramas de Raios X permitem o agrupamento dos complexos [TR(DBM)3(L)2] em uma mesma série isomórfica. Os espectros de emissão exibem desdobramentos das transições 5D0→7FJ (J=O-4) para os complexos de Eu3+ e 4G5/2→ 6HJ (J=5/2-11/2) para o Sm3+, que obedecem à regra de seleção 2J+1 e J+½, respectivamente. Os altos valores de parâmetros de intensidade Ω2 dos complexos de Eu3+ indicam que o íon TR encontra-se em um ambiente químico altamente polarizável. As curvas de decaimento dos níveis emissores 5D0 (Eu3+) e 4G5/2 (Sm3+) apresentam comportamento mono-exponencial para os complexos indicando a inexistência de outro processo de depopulação. Os valores de tempos de vida (τ) do nível emissor 5D0 dos Eu3+ complexos com ligantes sulfóxidos são maiores do que o complexo hidratado. Os complexos contendo ligantes sutfóxidos apresentam valores de eficiência quântica de emissão (η) e rendimento quântico experimental (q) superiores aos complexos hidratados devido os osciladores OH. Os espectros de emissão do [Eu(DBM)3(PTSO)2] em soluções (etanol ou acetona) e em filmes apresentam perfis similares ao complexo no estado sólido. Tais resultados indicam que os dispositivos podem ser confeccionados através das técnicas em solução (spin coating, dip coating, \"silk screening e ink jetting). Os espectros de fosforescência dos complexos de Gd3+ apresentam as bandas referentes aos estados tripletos (T) do DBM (~486 nm); as quais estão ausentes nos espectros de emissão dos complexos de Eu3+ e Sm3+, indicando uma eficiente transferência de energia do estado T do ligante para os níveis emissores 5D0 do íon Eu3+ e 4G5/2 do íon Sm3+. O complexo [Eu(DBM)3(PTSO)2] foi utilizado como camada emissora de luz vermelha na confecção dos dispositivos eletroluminescentes (EL); os quais foram confeccionados através da técnica de deposição física a vapor e apresentam as seguintes estruturas: (1) ITO / MTCD / [Eu(DBM)3(PTSO)2] / Alq3 / AI; (2) ITO / NPB / [Eu(DBM)3(PTSO)2] / Alq3 / Al; e (3) ITO / NPB / [Eu(DBM)3(PTSO)2] / Al. O filme depositado de MTCD= 1-(3-metilfenil)-1,2,3,4-tetrahidroquinolina-6-carboxialdeído-1,1-difenilhidrazona e NPB= N, N\'-bis(1-naftil) - N, N\'- difenil - 1,1\' - bifenil - 4, 4\'- diamina, atuam como transportadores molecuares de lacunas (buracos). O composto Alq3 [tris(8-quinolinonato)alumínio(III)] atua como transportador de elétrons. Deve-se ressaltar que o [Eu(DBM)3(PTSO)2] também apresentam propriedades de transportadores de elétrons, o que tende a reduzir os custos de produção dos dispositivos EL orgânicos. A última camada do dispositivo eletroluminescente corresponde ao alumínio, o qual atua como catodo e refletor. Os espectros eletroluminescentes dos dispositivos exibem emissões características das transições 5D0→ 7FJ oriundas do íon Eu3+. A caracterização elétrica dos dispositivos indica que o dispositivo bi-camada apresenta maior eficiência do que o tri-camada. As coordenadas CIE (Commission Internationale de l\'Eclairage) dos dispositivos EL apresentam contribuições da emissão do NPB (400-600 nm) e da transição 5D1→ 7F1 do íon . Este problema pode ser solucionado com a alteração da arquitetura dos dispositivos (NPB, MTCD, TDP e Alq3).This work presents the synthesis and photo and electroluminescent study of rare earth (RE3+= Eu3+, Gd3+ and Sm3+) β-diketonate (dibenzoylmethane - DBM) complexes with hydrated and sulfoxide ligands (L= benzyl sulfoxide -DBSO, methyl sulfoxide - DMSO, phenyl sulfoxide - DPSO and p-tolylsulfoxide - PTSO). The complexes were characterized by the following techniques: i) elemental analysis of carbon and hydrogen; ii) analysis of RE3+ by complexometric titration; iii) X Rays diffraction patterns; iv) thermal anaiysis; v) IR spectroscopy and vi) scanning electron microscope (SEM). The TG/DTG curves of [RE(DBM)3H2O] and [RE(DBM)3(L)2] complexes present stages of thermal decomposition well defined for the complexes and indicate higher thermal stability when compared with hydrated complex. The IR spectral data indicate that the coordination of organic ligands (DBM and sulfoxides) to RE3+ ions occur through the oxygen atoms. The photomicrographs obtained from films indicate which vacuum and solution techniques can give films with good quality. The X Rays diffraction patterns suggest that the [RE(DBM)3(L)2] complexes are in the same isomorfic series. The emission spectra of the complexes exhibit the 5D0→7FJ transitions (J=0-4) from the Eu3+ ion and 4G5/2→6HJ (J=5/2-11/2) from the Sm3+ ion, which follow the selection rule 2J+1 and J+½, respectively. The high values of the Ω2 intensity parameters of Eu3+ complexes indicate that the RE ion is in a highly polarizable chemical environment. The luminescence decay curves show a mono- exponential behavior for the complexes indicating the inexistence of other channel depopulation. The lifetimes (τ) values of the emitting level from RE3+ -complexes with sulfoxide ligands are higher than hydrated complexes. The complexes containing sulfoxide ligands present higher values of emission quanturn efficiency (η) and quantum yield (q) than hydrated complexes due OH oscillators. The emission spectra of [Eu(DBM)3(PTSO)2] in solutions and fiIms show the similar spectrum profles compared with that in solid state. These results indicate device construction could be realized from solution techniques as spin coating, dip coating, silk screening and ink jetting. The phosphorescence spectra of the Gd3+-complexes show broaden bands arising from the triplet states (T) of the DBM-(~486nm); which are absent in the emission spectra for the RE3+ complexes indicating an efficient energy transfer from the (T) state of the ligand to the emitting level 5D0 and 4G5/2 of Eu3+ and Sm3+ ions, respecfively. The complex [Eu(DBM)3(PTSO)2] was utilized as emitting layer of red light in construction of electroluminescent (EL) devices. These devices were constructed through Physical Vapour Deposition (PVD) technique and they present the following structures: (1) ITO / MTCD / [Eu(DBM)3(PTSO)2] / Alq3 / AI; (2) ITO / NPB / [Eu(DBM)3(PTSO)2] / Alq3 / Al; e (3) ITO / NPB / [Eu(DBM)3(PTSO)2] / Al The MTCD =1-( 3-methylphenyl)-1,2,3,4-tetrahydroquinoline-6-carboxyaldehyde-1,1-diphenyilhydrazone; and NPB =N,N-diphenyl-N,N-bis(1-naphthyl)-1,1-biphenyl-4,4\'-diamine, act as hole transporting layer (HTL). The Alq3, (8-hydroxyquinoline aluminum) thin film act as electron transporting layer (ETL). The [Eu(DBM)3(PTSO)2] complex shows electron transport properties; which tend to reduce the cost of production of this type of organic electroluminescent (EL) devices. The last layer is the Al (aluminum) thin íilm, which act as cathode and reflector of emitted light. The CIE (Commission Internationale de l\'Eclairage) coordinates of the EL devices show contributions of emission from the NPB (400-600 nm) and 5D1→ 7F1 transition from the Eu3+ ion. This problem can be solved with alteration h the architecture of the device (NPB, MTCD, TPD and Alq3.
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White, Stephen A. "A study of the diastereoselectivity of [gamma]-chiral-[alpha], [beta]-unsaturated sulfoxides and sulfones in the Michael reaction with lithium dimethyl cuprate." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/25972.
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Chen, Yi. "SYNTHESIS OF THE PENTAVALENT IODINE COMPOUND, DIPHENYLIODOSYL TOSYLATE, AND ITS USE FOR THE OXIDATION OF SULFIDES." University of Akron / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=akron1186450610.
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Jivishov, Emil [Verfasser], and Michael [Akademischer Betreuer] Keusgen. "Investigations on Wild Allium Species. Part I: Cysteine Sulfoxides of Flowers. Part 2: Anticancer Activity of Bulb Extracts. / Emil Jivishov ; Betreuer: Michael Keusgen." Marburg : Philipps-Universität Marburg, 2019. http://d-nb.info/1176106791/34.
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Costa, Luiz Antonio Mendonça Alves da. "Reações de oxidação e hidrolise por microrganismos nos metodos de biocatalise e de biorremediação." [s.n.], 2005. http://repositorio.unicamp.br/jspui/handle/REPOSIP/249096.
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Orientador: Anita Jocelyne MarsaioliTese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: O presente trabalho foi dividido em dois projetos: a avaliação do potencial biocatalítico de microrganismos isolados da abelha Trigonna sp e o estudo de biorremediação de ambiente contaminado por Alachlor®. A atividade catalítica de oxidação de sulfeto e a hidrólise de éster sulfínico de 12 linhagens de fungos foi avaliada durante a primeira parte deste trabalho, dentre das quais, 8 linhagens foram isoladas do corpo da abelha Trigonna sp em trabalhos anteriores do nosso grupo. Os melhores microrganismos na oxidação enantiosseletiva do etil fenil sulfeto foram os Fungo CCT 5553 e Cladosporium sp. CBMAI 0210 que produziram o (S)-etil-fenil-sulfóxido (ee > 99%) e (R)-etil-fenil-sulfóxido (ee 97%), respectivamente. O (S)-etil-fenil-sulfóxido (ee > 92%) foi aplicado na síntese da S-(+)-4-metil-3-heptanona, feromônio de alarme da formiga do gênero Atta, mas uma racemização durante a eliminação do grupo sulfinila impossibilitou a síntese total. Para a resolução enzimática de (±)-benzenossulfinato de cicloexila foi selecionado os fungos Penicillium sp. CBMAI 0208 e Aspergillus ochraceus CBMAI 0211 ambos fornecendo os produtos com excessos enantioméricos > 99%. Na segunda etapa, avaliou-se a capacidade de degradação do pesticida Alachlor® de 6 linhagens de bactérias (Streptomyces sp.) e as estruturas dos produtos de degradação foram sugeridas baseados em seus padrões de fragmentação. Entre esses 8-etil-quinolina e N-metil-8-etil-indol nunca foram citados nos estudos de biodegradação do Alachlor®.
Abstract: The work presented in this thesis is divided into two projects: the evaluation of the biocatalytic potential of microorganisms isolated from Trigonna bee and those deposited in two brazilian collections and bioremediation of Alachlor contamined soil. The sulfide oxidation and sulfinic esters hydrolysis catalytic activity was screened using 12 different fungi strains, 8 of which were previously isolated from a Trigonna sp. bee. The best microorganisms for the enantioselective oxidation of ethyl phenyl sulfide were Fungus CCT 5553 and Cladosporium sp. CBMAI 0210 WHICH PRODUCED (R)-ethyl phenyl sulfoxide (ee 97%) and (S)-ethyl phenyl sulfoxide (ee > 99%) respectively. The chiral (S)-ethyl phenyl sulfoxide which was applied in the synthesis of S-(+)-4-methyl-3-heptanone, ant alarm pheromone (genus Atta), of but racemization during sulfinyl group elimination step precluded the total asymmetric synthesis. For the enzymatic resolution of the cyclohexyl (±)-benzenosulfinate we have selected Penicillium sp. CBMAI 0208 and Aspergillus ochraceus CBMAI 0211 both with the capacity of resolving the sulfinate in over 99 enantiomeric excess. In the second part, the Alachlor® degradation potential of 6 bacterium strains (Streptomyces sp.) was evaluated and the structures of biodegradation products were suggested based on their mass fragmentation patterns. Among these 8-ethyl-quinoline and N-methyl-8-ethyl-indole have never been mentioned as Alachlor biodegradation products before.
Doutorado
Quimica Organica
Doutor em Quimica
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Serreqi, Alessio N. "Hydrolase catalyzed resolutions of enantiomers : a structural basis for the chiral preference of lipases : preparation of enantiomerically-pure phosphines, phospine oxides, sulfoxides and pipecolic acid." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28918.
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Enantiomerically-pure compounds are becoming increasingly important particularly to the pharmaceutical industry. Enzymes are useful tools in the synthesis of such compounds. To better understand how lipases discriminate between enantiomers of chiral secondary alcohols we obtained x-ray crystal structures of covalent complexes of Candida rugosa lipase with the transition-state analogs (1R)-menthyl hexylphosphonate and (1S)-menthyl hexylphosphonate. These compounds are transition-state analogs for the hydrolysis of menthyl esters. We observed that the transition-state analog of the unfavored (1S)-enantiomer of menthol disrupted the hydrogen bond between N$ varepsilon$2 of histidine 449 and the menthol oxygen. His 449 is part of the catalytic triad in CRL. This may account for the slower reaction of the (1S)-enantiomer of menthol. The crystal structures also identified binding site regions for secondary alcohols in CRL. These regions are common among many lipases and esterases and account for their common enantiopreference toward secondary alcohols.Lipases and esterases can resolve compounds with phosphorus and sulfur stereocenters by hydrolysis of a pendant acetoxy group. Both CRL and cholesterol esterase have high selectivity for (2-acetoxy-1-naphthyl)methylphenylphosphine oxide. They resolved this substrate with and E of 81 and 32 respectively. A synthetic scale resolution of this substrate with subsequent recrystallization and chemical transformation followed by stereospecific reduction gave both enantiomers of (2-methoxy-1-naphthyl)methylphenyl-phosphine with 96-97% ee. This chiral phosphine is potentially useful in asymmetric syntheses.
CE is the most selective enzyme for the sulfur substrates tested but these enantioselectivities were moderate, E's ranged from 5 to 25. From the CE resolution of the phosphorus and sulfur compounds and others we propose an empirical model that predicts which enatiomer reacts faster. The model is based on the size of the substituents and their conformational preferences.
Crude Aspergillus niger resolves esters of pipecolic acid with an E of 20 $ pm$ 4. A simple partial purification of ANL by fractional precipitation with ammonium sulfate increased the enantioselectivity to $>$100. The partially purified ANL can be used in a synthetic scale resolution of ($ pm$)-n-octyl pipecolate to give (S)-($-$)-pipecolic acid (93% ee) and (R)-(+)-pipecolic acid (97% ee).
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Stoffregen, Stacey Anne. "Palladium(II) and platinum(II) synthetic peptidases residue- and sequence-selective hydrolysis and the photochemistry of sulfoxides, S,C-sulfonium ylides, and sulfilimines: unimolecular bond cleavage/." [Ames, Iowa : Iowa State University], 2007.
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Yalcouye, Boubacar. "Synthèse atropo-sélective de la partie biarylique de la (-)-stéganacine via le couplage croisé de Suzuki-Miyaura et le couplage ARYNE." Thesis, Strasbourg, 2014. http://www.theses.fr/2014STRAF059.
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Les propriétés biologiques intéressantes des biaryles à chiralité axiale ainsi que le défi lié à la construction de la liaison Csp2-Csp2 du motif biarylique ont suscité un vif intérêt des chimistes organiciens de synthèse. Les biaryles à chiralité axiale sont des structures privilégiées en chimie médicinale ainsi qu’en catalyse asymétrique. L’objectif de notre recherche était le contrôle de la chiralité axiale de la (-)-stéganacine en utilisant deux approches atropo-sélectives distinctes: couplage croisé de Suzuki-Miyaura (en présence de métaux de transition), couplage ARYNE (sans métaux de transition). Le couplage croisé de Suzuki-Miyauraatropo-diastéréosélectif a été réalisé en utilisant des β-hydroxysulfoxydes énantiopurs comme auxiliaires de chiralité. Le biaryle diastéréopur issu de ce couplage croisé a été transformé en un intermédiaire rapporté dans la littérature sans épimerisation de la chiralité axiale. La seconde approche était le couplage ARYNE atropo-diastéréosélectif, et fut testée dans un premier temps avec le p-tolylsulfoxyde énantiopur. Cependant nous avions rencontré un problème de manque de réactivité de l’arylsulfoxyde lithié. En revanche la chiralité axiale de la (-)-stéganacine a été contrôlée en utilisant des oxazolines comme auxiliaires de chiralitéThe interesting biological properties of axially chiral biaryls and the challenge of Csp2-Csp2 bond formation ofthe biaryl motif have aroused keen interest among synthetic organic chemists. The axially chiral biaryls areprivileged structures in medicinal chemistry and in asymmetric catalysis. The goal of our research is based onthe control of the axial chirality of (-)-steganacin using two differents atropo-selective approaches: Suzuki-Miyaura cross-coupling (in presence of transition metals), and ARYNE coupling (without any transitionmetals). The atropo-diastereoselective Suzuki-Miyaura cross-coupling was carried out using enantiopure β-hydroxysulfoxydes as chiral auxiliary. The resulting diastereopure biaryl was converted into an intermediatereported in the literature without any epimerization of axial chirality. The second approach was the atropodiastereoselectiveARYNE coupling which was tested for the first time with the enantiopure p-tolylsulfoxyde.However, we encountered a problem due to lack of reactivity of lithiated arylsulfoxide. Finally, the axialchirality of (-)-steganacin was controlled using oxazolines as chiral auxiliary
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Malacea, Raluca. "Utilisation de ligands bifonctionnels chiraux pour la catalyse asymétrique impliquant des complexes d'hydrures." Toulouse 3, 2006. http://www.theses.fr/2006TOU30054.
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Après une introduction bibliographique sur les ligands bifonctionnels P,N et P,S utilisés en catalyse asymétrique (Chapitre I), le chapitre II décrit la synthèse de nouveaux composés P,P-diaminoalkyl-phosphine et P,P,P-triamino-phosphine dérivés de diamines chirales et leur utilisation dans l'hydroformylation du styrène. Dans le chapitre III, nous avons étudié la chimie de coordination de ligands phosphine-thioéther ferrocéniques chiraux avec le platine, le palladium, l'iridium, le rhodium et le ruthénium pour donner une grande variété des complexes. La chiralité planaire du ferrocène contrôle la configuration du soufre asymétrique, crée par complexation. Les complexes d'iridium ont donné de très bonnes activités et énantiosélectivités ( e. E. Jusqu'à 99%) dans l'hydrogénation asymétrique de cétonesAfter a bibliographic introduction on bifonctional P,N and P,S ligands used in asymmetric catalysis (Chapter I), in the chapter II is described the synthesis of new compounds P,P-diaminoalkyl-phosphine and P,P,P-triamino-phosphine from chiral damines and their application in styrene hydroformylation. In the third chapter, we studied the coordination chemistry of chiral phosphine-thioether ferrocenic ligands with platinum, palladium, iridium, rhodium and ruthenium and we obtained a great variety of complexes. The configuration of the sulphur atom, which became asymmetric after coordination, is totally controlled by the planar chirality of ferrocene. Iridium complexes gave high activity and excellent enantioselectivity (e. E. Up to 99%) in the asymmetric hydrogenation of ketones
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Itsenko, Oleksiy. "Photoinitiated Radical Carbonylation Using [11C]Carbon Monoxide : 11C-Labelling of Aliphatic Carboxylic Acids, Esters, and Amides." Doctoral thesis, Uppsala universitet, Kemiska institutionen, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6021.
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One-step photoinitiated free radical carbonylation was employed for the rapid (5–7 min) labelling of aliphatic carboxylic acids, esters, and amides with a short-lived positron emitter 11C (t½ = 20.3 min) at the carbonyl position. The labelled compounds were synthesized from alkyl iodides (0.05–0.1 mmol), [11C]carbon monoxide, and appropriate nucleophiles. Decay-corrected radiochemical yields were up to 74%; conversion of [11C]carbon monoxide reached 85–90%; specific radioactivity was 158–192 GBq/mmol. The labelled compounds were identified and characterized using HPLC, LC-MS, and 1H and 13C NMR. The effects of solvents, additives, photoirradiation, temperature, and reaction time were studied and discussed. [carbonyl-11C]Amides were synthesized using amines in 1–2 equiv. to iodides, exploiting solvent effects to control reactivity. [carboxyl-11C]Acids were synthesized using water as a nucleophile, in binary and ternary aqueous solvent mixtures; the addition of TBAOH or KOH was necessary to obtain high radiochemical yields. [carbonyl-11C]Esters were synthesized using primary and secondary alcohols, tert-butanol, and phenol. Bases were KOH, BuLi, LiHDMS. The effects of photosensitizers were studied and exploited to accelerate the labelling of carboxylic acids and esters resulting in 75–85% decay-corrected radiochemical yields under mild conditions without the use of bases. A mild procedure for the 11C-carboxylation of alkyl iodides using DMSO as an oxygen nucleophile was developed. This method is expected to be suitable in the macroscale synthesis of carboxylic acids using isotopically unmodified carbon monoxide. Radical carbonylation was applied to improve the synthesis of an extensively used PET tracer, [carbonyl-11C]WAY-100635. The tracer was synthesized in one step, whereas a common approach via Grignard reagents requires three steps. In addition, several (13C)compounds were synthesised using the described methods. Free radical carbonylation may be used for the 11C-carbonylation of alkyl iodides, whereas transition-metal carbonylation – of aryl halides and triflates. Thus, the two carbonylation methods are complementary with respect to the scope of synthetic targets.
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Itsenko, Oleksiy. "Photoinitiated Radical Carbonylation Using [11C]Carbon Monoxide : 11C-Labelling of Aliphatic Carboxylic Acids, Esters, and Amides." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis: Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-6021.
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