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Showing 1 to 20 of 28 for “"Phosphine oxides"”.
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Synthesis and characterization of novel bismaleimides derived from arylene phosphine oxides and ether-ketones
Bismaleimides containing either bisphenoxy phosphine oxide or bisphenoxy carbonyl linkages have been synthesized in high yields from bis(4-fluorophenyl) phenyl phosphine oxide or para-[bis(4-fluorobenzoyl) ]benzene via a two step process. The respective activated aryl halides were first reacted …
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Unsymmetrical tridentate phosphine ligands
… synthetic route, via phosphonium salts and phosphine oxides has been developed for the preparation of unsymmetrical triphosphine ligands, which necessarily contain one central chiral phosphorus atom. The ttparent" tridentate phosphine is (2- diphenylphosphinoethyl)(3-diphenylphosphinopropyl) …
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The Synthesis and Application of a Chiral Sulfonated Phosphine Ligand to Asymmetric Transition-Metal Catalysis
… describes the synthesis of a chiral sulfonated phosphine ligand, sSPhos, in its enantiopure form and its subsequent application in asymmetric transition-metal catalysis. sSPhos is a dialkylbiaryl phosphine ligand bearing a sulfonate group. This sulfonate group can engage in non-covalent …
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Synthetic and stereochemical aspects of enantioselective copper catalysed C-H insertion reactions leading to cyclopentanones and sultones
… including α-diazoβ-keto sulfones, α-diazo-β-keto phosphine oxides, 2-diazo-1,3-diketones and αdiazosulfonates, and their reactivity in intramolecular copper–bis(oxazoline)–NaBARF catalysed C–H insertion reactions. Excellent enantioselectivities of up to 91% ee were achieved in the synthesis of …
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Synthesis and properties of potentially liquid crystalline phosphorus compounds
… crystalline phase behaviour. Trigonal pyramidal phosphines together with the corresponding tetrahedral phosphine oxides, with three alkoxybiphenyl groups attached to a central phosphorus atom, were synthesised with varying alkyl chain lengths between C1-C22. Investigation into liquid crystalline …
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Greener Photoredox-Catalyzed Phosphonations of Aryl Halides
Aromatic phosphonates and phosphine oxides are highly desirable synthetic targets used in pharmaceuticals, natural products, agrichemicals, catalysis, and materials science. While a variety of aromatic precursors have been used to access these motifs, aryl halides remain one of the most desirable …
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Chirality Transfer in Acyclic Allylic Systems and New Pd-Catalyzed Heck Reaction/C-H Activation Cascades
… 110 °C and led to enantiomerically pure allylic phosphine oxides. The substitution pattern of the substrate and the reaction conditions were fully optimized.The chirality transfer concept was also used intermolecularly in asymmetric allylic substitution reactions. This allowed to build up …
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Expanding Deoxygenative Transformations of Alcohols by Phosphorus Compounds Through Geometric Deformation
… transformations by forming strong P=O bonds in phosphine oxides. While typical trigonal σ³-P compounds are nucleophilic, it has been demonstrated that lowering the C₃ᵥ-symmetry of σ³-P compounds to Cₛ-symmetry leads to enhanced electrophilicity of the P-center. Such electrophilic character of …
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Doubly Bonded Derivatives of Si and Ge: Cycloaddition Reactions and Polymer Chemistry
… the addition of the 1,3-dipolar nitrogen oxides to the (di)tetrelene gave 5-membered ring adducts via a formal [3+2] cycloaddition where the (di)tetrelene acts as the 2p component and the nitro/nitrone act as the 4p component. In some cases, the ring underwent rearrengment or cleavage to …
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CHIRAL LEWIS BASES ACTIVATION OF TRICHLOROSILYL DERIVATIVES
… compounds: phosphoramides, phosphoramidates and phosphine oxides. These compounds, in presence of trichlorosilyl derivatives, generate hypervalent cationic species able to promote stereoselective C-H bond formations (by reaction with HSiCl3) and stereoselective C-C bond formations as allylation …
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Characterization of the molecular structure at modified polymer surfaces and polyphenylene sulfide/copper interphases
… polyphenylene sulfide, and poly(arylene ether) phosphine oxides was also examined by these techniques and optical theory used to optimize experimental conditions. Results after plasma treatment indicated a very thin modified surface layer (< 10 nm) where the thickness and specific surface …
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Asymmetrische Synthese von allylischen Alkoholen mittels Palladium-katalysierter asymmetrischer Transformation von allylischen Carbonaten und Synthese neuer Sulfoximin-Phosphane
… classes of sulfoximines, alpha-(N-sulfoximido) phosphines, phosphine oxides and phosphonates, were synthesized from N-vinyl sulfoximines. These new sulfoximines could possibly serve as ligands or as an analogue to the bioactive alpha-aminophosphonic acids. Further investigations of the N-vinyl …
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Synthesis and Characterization of Phosphine Oxide Containing Monomers and of the Flame Resistant Polymers Prepared Therefrom
… monomers, principally monomers containing aryl phosphine oxide units. Utilization of these monomers was demonstrated in various types of linear and network polymerizations. The diamines monomers included bis(3-aminophenyl) methyl phosphine oxide (DAMPO), bis(3-aminophenyl) phenyl phosphine oxide …
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Synthesis and Characterization of Bis-Phosphine Complexes with Transition Metals
… primarily in phosphonates, phosphates and phosphine oxides. The omission of phosphorus is interesting from two points. First, many of the precious and heavy metal ions of interest (Pd2+, Ag+, Pt2+, Pb2+, Cd2+and Hg2+) can be classified as soft Lewis acids, according to Pearson’s HSAB …
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Development of N-heterocyclic carbene ligands for nanomaterials in aqueous media and expanding the interface of metal-organic framework (MOF) and polymer chemistry via polyMOFs
… classes such as thiols, carboxylic acids, phosphines, ammonium salts, and phosphine oxides. Our studies have focused on ligand design for gold nanoparticles (NPs) and nanorods (NRs) in aqueous media. Using a polyethylene glycol (PEG)-conjugated NHC strategy, we demonstrate the first example …
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Development of Highly Reactive Sulfone Iminium Fluoride Reagents and Their Application in Fluorine Methodologies
… was also possible from the corresponding phosphine oxides albeit at a slower reaction rate.</p> <p>In the third part of this work, we explore a modified Beckmann rearrangement using SIFs. We find that the reaction of a range of ketoximes with SIF rapidly produces imidoyl fluorides in 60 …
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