Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 27 for “"Macrocyclization"”.
-
Characterizing and Engineering Thioesterases as Biocatalysts for Macrocyclization
… high affinity and specificity. While synthetic macrocyclization poses considerable challenges, nature effortlessly generates these complex molecules using thioesterase (TE) domains positioned at the C-terminus of modular biosynthetic machinery. This has spurred researchers to explore the use of …
-
Organometallic Palladium Reagents for Polypeptide Bioconjugation and Macrocyclization
Chapter 1: Bicyclic peptides have been developed to mimic good binders that structurally resemble antibody mimetics. The identity of the linker plays a critical role in enforcing the structure of the cyclic entity. Palladium-mediated arylation has enabled cysteine-specific modifications with a …
-
I. Depolymerization-macrocyclization of (o-phenylene-ethynylene)-alt-(arylene-ethynylene) copolymers II. Improving existing water filtration membranes via covalent modification
I. Depolymerization-Macrocyclization of (o-Phenylene-Ethynylene)-alt-(Arylene-Ethynylene) Copolymers The synthesis of shape-persistent arylene-ethynylene macrocycles via alkyne metathesis remains an open area of investigation due to gaps in understanding about how monomer structure affects product …
-
Phosphine-promoted cross-coupling reactions of propargylcopper reagents and alkenyl iodides and the total synthesis of (-)-gloeosporone via nickel-catalyzed epoxide-alkyne reductive macrocyclization
… via Nickel-Catalyzed Epoxide-Alkyne Reductive Macrocyclization. The total synthesis of macrolide natural product (-)-gloeosporone 1 is described in 10 steps (LLS) and 5.2% overall yield. The key macrocyclization was performed via nickel-catalyzed reductive macrocyclization of an alkyne and a …
-
Synthesis and Biosynthesis of Polyketide Natural Products
… biosynthetic details of thioesterase-catalyzed macrocyclizations in polyketide natural products. The outcome of the enzyme's activity is divided between hydrolysis and macrocyclization and limited information is currently available pertaining to its selectivity. We synthesized four …
-
Enantioselective nickel-catalyzed reductive coupling reactions of alkynes and aldehydes. Synthesis of amphidinolides T1 and T4 via catalytic, stereoselective macrocyclizations
… and T4 via Catalytic, Stereoselective Reductive Macrocyclizations Total syntheses of amphidinolides T and T4 were achieved using two nickelcatalyzed reductive coupling reactions of alkynes, with an epoxide in one case (intermolecular) and with an aldehyde in another (intramolecular). The latter …
-
C—H oxidation reactions in complex molecule synthesis: application and development
… biasing elements in order to effect 14-membered macrocyclization. This work showcases the cyclizations of completely unbiased 6-deoxyerythronolide B precursors, using either C–H oxidative or Yamaguchi macrolactonization reactions. Late-stage and stereodivergent C–H oxidation reactions enabled …
-
Palladium reagents for bioconjugation
… Here we detail a method for a divergent macrocyclization of unprotected peptides by crosslinking two cysteine residues with bis-palladium organometallic reagents. These synthetic intermediates are prepared in a single step from commercially available aryl bis-halides. Two bioactive linear …
-
The synthesis of macrocyclic molecules related to telomestatin
… unit gave a linear tetraoxazole amide. The final macrocyclization was accomplished by using O-[(1-cyano-2-ethoxy-2-oxoethylidene)amino]-oxytri(pyrrolidin-1-yl) phosphonium hexafluorophosphate (PyOxP) and the product (45% yield) was characterized by 1H NMR. Finally, the Cu (II) coordination …
-
Chemical Synthesis of Novel Calcium-Dependent Lipopeptide Antibiotics
… A analogues was accessed via in-solution macrocyclization of a side-chain protected linear precursor obtained by Fmoc-SPPS with a late-stage lipidation. Despite the lack of activity of the prepared analogues, the synthetic strategy reported herein can be easily applied to the …
-
Total Synthesis Of 1,10-Diphenylbicyclo[8.8.8]hexacos-5-ene
… work include a rare example of a large-scale RCM macrocyclization method useful on industrial scales, and the development of a multi-gram chromatographic method that allows reasonable separations using minimal amounts of silica (close to dry-loading amounts) and solvent. LAH workup was developed …
-
Synthesis of Taxol™ Analogs as Conformational Probes
… suggesting that a more flexible and efficient macrocyclization method will be needed to synthesize additional macrocyclic analogs.
-
Synthesis and Applications of Novel Responsive Materials
… nucleation-elongation polymerization or macrocyclization and pi-stacking depending on the length of the oligomer. The supramolecular properties of these responsive polymers are attributed to the palladium-pyridine coordination and pi-pi stacking. A responsive hydrogel, sensitive to …
-
Photochemical synthesis of dihydroquinolinones and their investigation toward macrocycle synthesis via ring expansion
… compounds is typically done using an end-to-end macrocyclization approach. However, challenges arise due to competing intermolecular reactions leading to the use of high dilution conditions. It is therefore important that synthetic chemists develop general and modular methods for their synthesis …
-
Advancing the field of polypeptoids through the synthesis of novel architectures and thermoresponsive polymers
… make this structure, including high dilution for macrocyclization and linear contaminants in the final product. Typical polymer characterization of this novel architecture suggested that these structures were cyclic and contained poly-ethylene glycol side chains. Polypeptoids that respond to …
-
Effects of shape, conformation, and symmetry on macrocycle synthesis via alkyne metathesis
… the influence of various factors on dynamic macrocyclization. Specifically, this work involves the synthesis of structurally unique poly(arylene-ethynylene)s that undergo alkyne metathesis-mediated depolymerization. The effects of three structural properties on the distribution of macrocycles …
-
The Synthesis of Functionalized Glycosides: Coordination Chemistry, Antiparasitic Activity, Precursors to Conformationally Constrained Macrocyclic Architectures and Photophysical Properties
… glycosylation as the most suitable route for macrocyclization. Finally, the photophysical properties of a collection of glycosides and structural analogues was examined. This involved the synthesis of a family of substituted iminopyridyl compounds and the preliminary analysis of their …
-
Design and Synthesis of Natural and Unnatural Macrocycles
… building blocks and the utilization of diverse macrocyclization methods were carried out to rapidly increase skeletal diversity and complexity. Appendage diversification was performed to further modulate the physicochemical properties of the macrocycles. Cheminformatic analyses demonstrated that …
-
New methods for synthesis and modification of peptides and proteins
… proteins of various structures. Two-component macrocyclization of peptide isocyanates with bifunctional linkers was developed as an extension of the described chemistry. The resulting cyclic peptides were shown to be more proteolytically stable and more bioactive than their linear analogs. In …
-
Site-selective modification of cysteine residues
… S-transferase (GST) catalyzed site-selective macrocyclization reaction for peptides up to 40 amino acids in length is also reported.
Page 1 of 2