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Showing 1 to 17 of 17 for “"Phosphoramidites"”.
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Chirale Phosphortriamide und Phosphin-Phosphoramidite als Liganden für die asymmetrische Katalyse
… structures (phosphorus triamides or phosphine-phosphoramidites respectively) are taken into account. These lead structures are varied via modular synthetic routes. In summary 12 new chiral ligands – 9 phosphorus triamides and 3 phosphine-phosphoramidites – have been synthesised and applied to …
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Novel approaches to the synthesis of selenium modified nucleosides, nucleotides and nucleic acids
… fashioned the corresponding dimer phosphoramidites. <br/>Coupling of these phosphoramidites to solid-supported substrates was optimised under both manual and automated conditions and required only minor modifications to the standard DNA synthesis cycle. <br/><br/>Following initial …
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The Synthesis and Characterization of Glycol Nucleic Acids
… of a straightforward synthesis of the phosphoramidites for solid phase oligonucleotide synthesis. Chapter 2 describes work towards a new set of exocyclic amino protection groups which could be removed in less time and under milder conditions than those previously reported. This new …
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Synthesis and application of chiral phosphorous triamide ligands
… different from the related phosphites or phosphoramidites and their potential in enantioselective catalysis is not yet fully explored.
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Fluorescent anthracene tags for detection of base pair mismatches in DNA duplexes
Non-nucleosidic anthracene-functionalised phosphoramidites 5a and 5b have been synthesised. 5b has been incorporated into oligonucleotide sequences (PrA, PrB, PrC, PrD, PrE, PrF and PrG) as a DNA base analogue using automated synthesis. Melting temperature (T\(_m\)) studies of double-stranded …
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Synthesis of oligonucleotide analogues for use in DNA nanostructures
… fulfil this<br/>requirement on lipid membranes, phosphoramidites monomers modified with a<br/>cholesterol moiety and a spacer unit were synthesised. The hydrophobic spacer provides<br/>separation between the hydrophobic cholesterol moiety and the phosphate backbone of<br/>the DNA strand. For …
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Site-Specific Labelling of Nucleic Acids by Catalyst-Free 1,3-Dipolar Cycloadditions
… blocks generated by NOAC. Three isoxazole phosphoramidites were prepared. Following in situ generation of the nitrile oxides from 1,2-, 1,3- or 1,4-disubstituted hydroxyethoxybenzaldehyde oximes and highly regioselective cycloadditions to a simple alkyne, the isomeric isoxazoles were …
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Synthesis and detection of dna damage
… by TBS for the convenience of conversion to phosphoramidites are also developed. The C-glycosidic bonds of these compounds are demonstrated to be stable under strong acidic and basic conditions. These analogues will become versatile tools to study the replication and repair of DNA alkylation …
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Molecule recognition of nucleic acids, nucleosides, nucleotides, and their derivatives
… site in a sequence specific manner. Two modified phosphoramidites were synthesized and incorporated into the 5' end of TFOs. The activity was evaluated by using various biophysical and biochemical experiments. The work reported in chapter 4 is focused on the G-quadruplex structure formed in the …
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An Inverse Electron-Demand Diels-Alder Strategy for Mapping RNA Methylation
… synthesis of the required allyl-modified phosphoramidites was also devised directly from a commercially available precursor. Using synthetic RNA oligonucleotides, it was demonstrated that the IEDDA adduct acts as an effective steric block that consistently induces full truncation of cDNA …
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Potential prebiotic roles of (amino-)acylation in the synthesis and function of RNA
… of the 2'/3'-O-acetyl and 2'/3'-O-TBDMS phosphoramidites, in addition to preparation of a photolabile solid-phase support, are described. With the materials to hand the procedures for an automated synthesis of acetyl-RNA were optimised and several acetyl-RNA oligonucleotides were …
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Studien zur Totalsynthese von t-RNA
Im Rahmen der vorliegenden Arbeit wurden verschiedene Wege zur Synthese einer Volllängen-t-RNA untersucht, im Einzelnen die Verlängerung einer (n-1)-t-RNA um einen Baustein sowie die Ligierung mehrerer kleiner Teilfragmente. Ebenfalls untersucht wurde die Kupplungseffizienz der automatisierten …
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Asymmetrische Cycloisomerisierung von 1,6-Dienen
… from Wilke´s Azaphospholen, also monodentate phosphoramidites were tested as chiral ligands in the Ni-catalysed cycloisomerisation of 1,6-dienes. Here we observed that MonoPhos type ligands only show moderate activity and regioselectivity combined with no chiral induction. The use of MonoPhos …
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Characterization of Oligonucleotide Microarray Hybridization: Microarray Fabrication by Light-Directed in situ Synthesis – Development of an Automated DNA Microarray Synthesizer, Characterization of Single Base Mismatch Discrimination and the Position-Dependent Influence of Point Defects on Oligonucleotide Duplex Binding Affinities
… starting from nucleotide building blocks (NPPOC-phosphoramidites) - directly on the surface of the microarray. Great flexibility with regard to the choice of probe sequences is achieved by use of virtual photomasks on the basis of a spatial light modulator (Digital Micromirror Device, DMD, Texas …
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Entwicklung einer Synthesestrategie aminoacylierter Dimerfragmente der tRNA mittels Festphasensynthese
Für die Synthese misacylierter tRNA’s existiert ein Verfahren, welches von einer 3‘-seitig um zwei Nukleotide verkürzten tRNA ausgeht, die mittels T4 RNA Ligase mit einem zuvor über chemische Methoden aminoacylierten Dimerfragment (pdCpA-naa, naa: nicht natürliche Aminosäure) zu einer kompletten, …
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Synthese neuer QUINAPHOS-Derivate und deren Einsatz in der asymmetrischen Katalyse
In the present thesis the synthesis of new QUINAPHOS and Dihydro-QUINAPHOS derivatives is described. A major topic of the ligand modification was an enhanced accessiblity of the corresponding diastereomers. In case of derivatives which were 1-naphthyl-substituted in 2-position of the 1,2-dihydro- …