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Showing 1 to 20 of 55 for “"Biaryl"”.
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Structural studies on biaryl phosphines and palladium complexes composed of biaryl phosphines
… One highly effective class of ligand is that of biaryl phosphines. Herein are presented experimental and theoretical structural data on this class of phosphine that aids in elucidating what aspects of ligand architecture are beneficial for catalyst stability and reactivity. Additionally, examples …
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The synthesis and applications of a biaryl-based asymmetric phosphine ligand
The asymmetric biaryl backbone of a dialkylbiphenyl phosphine ligand was developed, synthesized, and resolved. The application of the chiral phosphine ligand to the asymmetric Suzuki-Miyaura cross-coupling reaction was also investigated. This phosphine ligand has yielded promising results in the …
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Ketone -Catalyzed Epoxidation of Alkenes With Oxone and Palladium -Catalyzed Biaryl Synthesis via Silacyclobutanes
… different and structurally diverse unsymmetrical biaryls have been prepared in good to excellent yields.
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Robust Nickel Catalysts Supported By Biaryl-Bridged Pyridyl-N-Heterocyclic Carbenes For Carbon Dioxide Reduction To Value-Added Products
… for catalysis. We report a family of biaryl-bridged pyridyl-N-heterocyclic carbene-based ligands and their corresponding nickel complexes. Ligand synthesis, structural characterization of complexes, and their application in electrocatalytic CO2 reduction are discussed.
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Towards the synthesis of RP66453
… target as its bis-macrocyclic core contains a biaryl axis that displays atropisomerism. The natural atropisomer of RP 66453 is less stable than its diastereoatropisomer. To date there have been no reported syntheses of the natural product, and just one reported synthesis of the unnatural …
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Suzuki-Miyaura mediated biphenyl synthesis: a spotlight on the boronate coupling partner
The biaryl motif is found in many natural and synthetic products that display a wide range of biological activities. This explains why biphenyls are widely encountered in medicinal chemistry as a privileged scaffold. The palladium-catalysed Suzuki-Miyaura (SM) coupling is one of the most important …
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IMPROVING THE SCOPE AND UNDERSTANDING OF THE SYMMETRIC AND ASYMMETRIC SUZUKI COUPLING REACTION
… Suzuki cross-couplings towards axially chiral biaryl products have also been detailed. Model reactions towards configurationally stable biaryl products were found to undergo a successful chiral induction with the use of chiral ferrocenyl ligand (R)-(S)-PPFA 180, with high enantiomeric excesses …
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Initial Studies on a Novel Target-Promoted DNA Alkylation System
… intramolecular hydrogen bonding system and biaryl system) were proposed and synthesized. The potential DNA QM alkylation was investigated by deoxyadenosine (dA) and deoxyguanosine (dG) alkylation with the biaryl system. Only one deoxynucleoside adduct was observed when dA or dG reacted with …
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Manganese-catalyzed carbonylation of alkyl iodides
… at the synthesis of tri- and tetra substituted biaryls, since they are important precursors to biaryl phosphine ligands. The project did not succeed due to stability problems of the formed substituted zirconium biaryl. A general method for the manganese-catalyzed carbonylation of alkyl iodides …
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Palladium-Catalyzed Cross-Coupling Reactions of Organosilanols: I. New Methods That Employ Alkynylsilanols and Bissilyl Reagents. II. Mechanistic Analysis of the Cross-Coupling of Aryldimethylsilanolates
… and characterized. These complexes produce biaryl products via ligand dissociation and transmetalation.
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Enantioselective Total Synthesis of the Kibdelones
… Novel methods for heterocycle synthesis and biaryl bond formation were also targeted as part of the synthesis. The kibdelones contain a chlorinated isoquinolinone and stereogenically rich tetrahydroxanthone heterocycles, which make them challenging synthetic targets. To synthesize these …
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i) Design and Synthesis of Butadiene Substrates for Organocatalytic Transformations ii) Synthesis of Functionalized Biaryls and Pyran Derivatives
… and instead yielded densely functionalized biaryl species which are of some synthetic interest. Our attentions were then turned to the directed synthesis of these biaryls. This was accomplished through the use of stoichiometric quantities of piperidine in order to reduce the potential for …
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Development of novel heterocyclic compounds as vascular targeting agents
… are described. The optimisation of a key biaryl precursor molecule for these analogues is described. This includes a brief overview of palladium catalysed coupling chemistry and a screen for suitable catalytic systems. In chapter three the development of an intramolecular ring closing …
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Palladium-catalyzed C-C, C-N and C-O bond formation
… by bulky, monodentate phosphine ligands with a biaryl backbone or the bidentate ligand, Xantphos, effectively promote the formation of ca-aryl carbonyl compounds. Base-sensitive functional groups are better tolerated when a weak base, such as K3PO4, is used. One of the most difficult …
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Synthesis and Characterisation of Dual CCR7/CXCR4 Antagonists
… to reduce metastasis in cancer. Novel potent biaryl sulfonamide CCR7 antagonists were synthesised and assessed by calcium flux assay. Several potential dual CCR7 and CXCR4 biaryl sulfonamide antagonists have been synthesised, these are hybrid compounds incorporating features from CCR7 …
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Synthesis and Characterisation of Dual CCR7/CXCR4 Antagonists
… to reduce metastasis in cancer. Novel potent biaryl sulfonamide CCR7 antagonists were synthesised and assessed by calcium flux assay. Several potential dual CCR7 and CXCR4 biaryl sulfonamide antagonists have been synthesised, these are hybrid compounds incorporating features from CCR7 …
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Investigation of aryldimethylsilanolates in palladium-catalyzed cross-coupling reactions and development of chiral bis-hydrazone ligands for asymmetric aryl-aryl couplings
The preparation of biaryls by palladium-catalyzed cross-coupling of aromatic bromides and chlorides with alkali-metal salts (potassium and sodium) of aryl- and heteroarylsilanols has been developed. The critical feature for the success of this method is the use of …
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Total Synthesis of Himastatin
… dimerization reaction to secure the C5–C5' biaryl linkage at the center of himastatin’s homodimeric structure. Application of the oxidative dimerization methodology enabled the preparation of dimeric C5–C5' cyclotryptophans, cyclotryptamines, and indolines via a radical-radical coupling …
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Mechanistic studies on palladium-catalyzed C-N cross-coupling reaction
… reductive elimination for catalysts based on the biaryl ligands XPhos, CyJohnPhos, CPhos, BrettPhos, RuPhos, and SPhos were evaluated. Analogues of SPhos demonstrated that electron-donation of the lower aryl group is key to the stability of the amido complex in accordance with theoretical …
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