Search for dissertations about: "heterocycles"

Showing result 21 - 25 of 46 swedish dissertations containing the word heterocycles.

  2. 21. Synthetic studies towards 7- and 8-membered N-heterocycles, particularly 1,4-pyrrolobenzodiazepines : total synthesis of fuligocandin A and B

    Author : Birgitta Pettersson; Karolinska Institutet; Karolinska Institutet; []
    Keywords : 1; 4-pyrrolobenzodiazepines;

    Abstract : This dissertation is concerned with the synthesis of 7- and 8-membered N-heterocycles, particularly 1,4-pyrrolobenzodiazepines. A non-chromatographic method for conversion of carbonyl-functionalities to the corresponding thiocarbonyls is described. READ MORE

  4. 22. Synthetic studies of heterocyclic natural products

    Author : Jeffrey J Mason; Karolinska Institutet; Karolinska Institutet; []
    Keywords : Heterocycles; alkaloids; natural products; luotonin A; cephalandole A; cephalandole B; benzoxazinone; tryptanthrin; ophiuroidine; pyrroloquinazolinone; isatin; Prey demethylation; pyridinium hydrochloride; demethylation; microwave synthesis;

    Abstract : The methods that were developed for the synthesis of the heterocyclic natural products luotonin A, ophiuroidine, cephalandole B, and the indol-3-yl-benzoxazinones of cephalandole A are described in this thesis. The reoccurrence of the 4(3H)-quinazolinone structure is a common theme throughout these studies, and an overview of some quinazoline chemistry is introduced in the first chapter. READ MORE

  5. 23. Application of metalation reactions for synthesis of sulfur/selenium-containing heterocyclic compounds

    Author : Hamid Shirani; Karolinska Institutet; Karolinska Institutet; []
    Keywords : Heterocycles; indoles; 3- arylthio indoles; thiopyranobisindoles; dibenzothiepins; 3; 3′-dithiobisindoles; alkaloids; echinosulfone A; cyclization; ortho-metalation; McMurry coupling; sulfides; sulfones and disulfides;

    Abstract : This thesis deals mainly with the synthesis of various sulfur/selenium-containing heterocyclic compounds, many of which include structural features present in several biologically active molecules, with particular emphasis on compounds of synthetic importance, such as indoles, as well as other heteroaromatic species. In the first part, an efficient procedure toward synthesis of new 3-(arylthio)indoles based on reactions of aryl Grignard reagents or lithiated heteroaromatics with protected 3,3′-dithiobisindoles is described. READ MORE

  6. 24. Synthesis of new building blocks for conjugated oligomers

    Author : Fredrik Allared; KTH; []
    Keywords : organic semiconductors; thiophenes; heterocyclic synthesis; dithienothiophene; naphthalene;

    Abstract : This thesis deals with the synthesis of new organicmaterials for electronic applications. Several new ring-formingmethods are employed to construct sulphur heterocycles: Tandemelectrophilic aromatic substitution and acid-catalyzedtransetherification of methoxythiophene, double electrophilicaromatic substitutions with ethane-1, 2-disulphenyl chloride,and also, the reaction of dienes with sulphur dichloride. READ MORE

  7. 25. Synthesis and Characterisation of Conjugated Polymers with High Electron Affinity

    Author : Maria Jonforsen; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; light-emitting diode; solar cell; quinoxaline; conjugated polymer; photodiode; 4-b]pyrazine; pyrido[3; synthesis; photo-oxidation; electron affinity; pyridine;

    Abstract : This thesis describes synthesis and characterisation of conjugated polymers with high electron affinities. Polymers of this type are desired, for example, for use in light-emitting devices or as electron accepting material in photodiodes/solar cells. READ MORE