Osztrovszky, Gyorgyi

Denne afhandling omhandler forskning, som er udført ved Danmarks Tekniske Universitet og Institute for Glycomics i perioden april 2008 – oktober 2011. Afhandlingen består at fire separate emner, som relaterer til metalorganisk kemi og kulhydratkemi. Projekt 1: Ultrahurtige Grignard additionsreaktioner i tilstedeværelse af protiske reagenser Additionen af allylmagnesiumbromid og benzylmagnesiumchlorid til carbonylforbindelser blev studeret i tilstedeværelse af protiske reagenser (f. eks. vand, methanol, ethanol, phenol). I et antal tilfælde og især ved brug af allylmagnesiumbromid blev det observeret, at carbonyladditionen var hurtigere eller sammenlignelig med protoneringen via reagenset. Projekt 2: Rutheniumkatalyseret syntese af amider fra primære alkoholer og aminer Den direkte syntese af amider fra alkoholer og aminer med samtidig frigivelse af brint er tidligere blevet opdaget i Madsengruppen. Yderligere udvikling af reaktionsbetingelserne blev undersøgt, hvorunder støkiometriske additiver og hydrogenacceptorer ikke var nødvendige, og reaktionerne blev katalyseret af ruthenium N-heterocykliske carbenkomplekser. To katalysatorsystemer blev fundet effektive til at fremme amideringen. Disse to systemer viste ingen væsentlige forskelle i reaktivitet, som indikerer at den samme katalytisk aktive forbindelse er i spil. Projekt 3: Syntese af en trisakkaridprobe som formoden denguevirus receptor Ved Institute for Glycomics har væsentlig forskningværet fokuseret på at identificere mulige receptorer for denguevirus (DENV). Baseret på tidligere studier blev GlcNAcß1-3Galß1-4GlcNAc trisakkaridet overvejet som en mulig virus receptor. Syntesen af trisakkaridproben er blevet gennemført ved kobling af den tilsvarende D-glucosamindonor og lactosaminacceptor efterfulgt af debeskyttelse. De biologiske undersøgelser er på vej. Projekt 4: Glykosylering med ubeskyttede acceptorerRegioselektiv Koenigs-Knorr glykosylering er blevet studeret med en række ubeskyttede acceptorer ved hjælp af organoborforbindelser, som enten kan aktivere eller blokere cis-dioler via esterdannelse. Ved hjælp af phenylborsyre er høj regioselektiv og stereospecifik dannelse af den glykosidiske bindingblevet gennemført.The present dissertation describes the research performed at the Technical University of Denmark and at the Institute for Glycomics in the period April 2008 – Oct 2011. The thesis involves four discrete topics related to organometallic and carbohydrate chemistry. Project 1: Ultrafast Grignard addition reactions inthe presence of protic agents The addition of allylmagnesium bromide and benzylmagnesium chloride to carbonyl compounds was studied in the presence of protic agents (e.g. water, methanol, ethanol, phenol). In a number of cases, especially by the use of allylmagnesium bromide the carbonyl addition was found to be faster or comparable to the protonation by the reagent. Project 2: Ruthenium catalyzed synthesis of amides from primary alcohols and amines The direct synthesis of amides from alcohols and amines with the simultaneous liberation of dihydrogen was previously discovered in the Madsen group. Further development of the reaction conditions were investigated, in which stoichiometric additives or hydrogen acceptors were not required and the reactions were catalyzed by ruthenium Nheterocyclic carbene complexes. Two catalyst systems were found to be effective promoters for the amidation. These two systems do not show any significant differences in reactivity indicating that the same catalytically active species is operating. Project 3: Synthesis of a trisaccharide probe as a putative dengue virus receptor At the Institute for Glycomics major research has been devoted to identify putative receptors for dengue virus (DENV). Based on previous studies the GlcNAcß1-3Galß1-4GlcNAc trisaccharide was considered as a putative virus receptor. The synthesis of the trisaccharide probe has been achieved by the coupling of the corresponding D-glucosamine donor and the lactosamine acceptor, followed by deprotection. The biological investigation is in process. Project 4: Glycosylation with unprotected acceptorsRegioselective Koenigs-Knorr glycosylation has been studied with a number of unprotected acceptors by means of organoboron derivatives, which can either activate or block cis-diols via ester formation. By means of phenylboronic acid high regioselective and stereospecific glycosidic bond formations were achieved

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Studies and Applications of Metals for the Synthesis of Carbinols, Amides and Carbohydrates

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Studies and Applications of Metals for the Synthesis of Carbinols, Amides and Carbohydrates

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