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Showing 1 to 18 of 18 for “"Palladium-catalyzed cross-coupling reactions"”.
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Palladium catalyzed cross-coupling reactions of allyl- and vinylsilanes
Palladium-catalyzed cross-coupling of γ-substituted allylic silanolates with aryl bromides was investigated. It was discovered that γ-selectivity is heavily influenced by the substituents at silicon. It is proposed that undergoing an activated pathway significantly lowers the selectivity of the …
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Preparative and mechanistic aspects of palladium-catalyzed cross-coupling reactions of alkali-metal arylsilanolates
… of a large number of arylsilanols undergo smooth cross-coupling with a wide range of aromatic bromides and chlorides. The critical feature for the success of these coupling reactions and their considerable scope is the use of bis(tri-tert-butylphosphine)palladium. Additionally, these studies have …
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The development of palladium-catalyzed cross-coupling reactions of allylic silanolate salts with aromatic bromides
The palladium-catalyzed cross-coupling of allylic silanolate salts with a wide variety of aromatic bromides was developed. The coupling of sodium allyldimethylsilanolate and 2-butenyldimethylsilanolate required extensive optimization to deliver the expected products in high yields. The reaction of …
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The Modified Stereospecific Stille Reaction: Palladium-Catalyzed Cross-Coupling Reactions Involving Secondary and Tertiary Alkyl Carbastannatranes
… first chapter, introduction of transition metal-catalyzed cross-coupling reactions is given. While the formation of C(sp<sup>2</sup>)–C(sp<sup>2</sup>) bonds has been studied extensively, C(sp<sup>3</sup>)-C(sp<sup>2</sup>) bond formation still presents a challenge due to competitive β-hydride …
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Palladium-Catalyzed Cross -Coupling Reactions of Organosilanolates: Methods Development and Application in the Total Synthesis of (+)-Papulacandin D
… silyl substituents were differentiated in the cross-coupling reaction through the initial use of base-promoted reaction conditions where only one silyl group was reactive with a range of aryl halides. The second silyl substituent then reacted under fluoride-promoted reaction conditions to …
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Palladium-Catalyzed Cross-Coupling Reactions of Heteroaryldimethylsilanols: New Methods for the Formation of Substituted Heterocycles Using Preformed and Isolated Silanolates
A procedure for the preparation of multi-substituted indoles using the Larock indole synthesis was developed. The heteroannulation reaction can be used to prepare 2,3-disubstituted indoles in good yields. The identification of a t-butoxysilyl ether as the masked silanol further expanded the scope …
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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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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
Mechanistic investigations of the palladium-catalyzed cross-coupling of aryldimethylsilanolates demonstrated that transmetalation proceeds directly from an arylpalladium(II) silanolate intermediate without external activation. Arylpalladium(II) silanolate complexes bearing phosphine ligands were …
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CONTINUOUS-FLOW STRATEGIES FOR THE PREPARATION OF ACTIVE PHARMACEUTICAL INGREDIENTS AND RELEVANT INTERMEDIATES
… and electrochemistry. In the first part, palladium-catalyzed cross-coupling reactions involving highly reactive organolithium reagents are investigated under continuous-flow conditions, demonstrating how precise control of reaction parameters allows safer handling and improved selectivity …
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Part A The application of fluorescence resonance energy transfer to reaction discovery Part B The stereodefined synthesis of tetrasubstituted olefins
… olefins. Regioselective and stereospecific palladium-catalyzed cross-coupling reactions were employed to incorporate a wide variety of substituents into the highly congested olefins, affording single isomer products in good yields.* *Please refer to dissertation for diagrams.
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2,3-Dihalofenoles: sustratos de partida versátiles para la síntesis de heterociclos funcionalizados regioselectivamente
… ortho-metalation strategy in conjunction with palladium-catalyzed cross-coupling reactions have been mainly used to achieve this goal. The potential of these synthetic routes is that they allow an easy access to a wide variety of interesting products in a regioselective way by employing …
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Stereospecific Csp3 cross-coupling for modular polyketide synthesis
Iterative cross-coupling represents a simple strategy for the synthesis of functional molecules that is inherently automatable. However, an important limitation to this platform is an inability to generate Csp3-rich, stereochemically complex molecules due to challenges in the coupling of alkyl …
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TRANSITION METAL CATALYZED CROSS-COUPLINGS OF ALKYL SULFONE ELECTROPHILES
… While their use as Csp2 electrophiles in cross-coupling dates to the early 1970’s, their potential as competent Csp3 electrophiles has not been recognized until recently. Our group has made significant contributions to the development of new cross-coupling methodologies utilizing alkyl …
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Naujų pirimidino - fenoksazino TADF spinduolių sintezė ir tyrimas /
… Suzuki-Miyaura and Liebeskind-Srogl palladium-catalyzed cross-coupling reactions. Synthesis protocol and convenient methods of synthesis of 4,6-di[4-(10-phenoxazinyl)phenyl]-5-methyl-2-methyltiopyrimidines were elaborated. Eleven new compounds were synthesized and characterized. Their …
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Solid Phase Synthesis of M-Phenylene Ethynylene Oligomer Heterosequences
… attached to ArgoGel(TM) solid support, and uses palladium-catalyzed cross-coupling reactions to form the desired mPE backbone in a monomer-by-monomer fashion. In order to rapidly access hexameric oligomers in a period of one to two days, efforts were taken to limit the need for deprotection steps …
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Palladium catalysis in the synthesis of polyaniline-related materials
The palladium-catalyzed aryl amination reaction, in conjunction with an orthogonal protective group scheme, forms the basis of two routes to oligoaniline precursors. One method consists of a bidirectional chain growth from a symmetric core piece, whereas the other involves a divergent-convergent …
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Synthesis and Characterization of Siloles, Silole-Containing Polymers and Photoswitchable Polymer Brush
… monomers, which will be applicable for various palladium catalyzed cross-coupling reactions. In cases where the preparation of reactively functionalized siloles were unsuccessful by our method, we were able to accomplish the synthesis in one additional step; nevertheless, our method is still …
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Design of New, More Stable, Precursors to Organopalladium(II) Complexes and Methods for the Palladium-Mediated Late-Stage Diversification of Pharmaceuticals
Chapter 1. Pharmaceutical Diversification via Palladium Oxidative Addition Complexes Palladium-catalyzed cross-coupling reactions have transformed the exploration of chemical space in the search for materials, medicines, chemical probes, and other functional molecules. However, cross-coupling of …