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Showing 1 to 20 of 20 for “"Anti-Markovnikov"”.
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Novel aza-arylphosphane ligands for ruthenium catalyzed anti-Markovnikov hydration of terminal alkynes
… Their application as catalysts for the anti-MARKOVNIKOV hydration of terminal alkynes was examined. Kinetic studies were performed in order to explore the structure-activity relationship of the ligands with the ultimate goal to identify highly active catalysts. Subsequently, the most …
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I. Palladium-catalyzed anti-Markovnikov oxidative amination of olefins II. Catalytic deracemization of axially chiral diols III. Three component carboamination of electron deficient alkenes
… First we have developed a palladium-catalyzed anti-Markovnikov oxidative amination of unactivated alkenes. This transformation allows for the generation of primary C–N bonds by coupling the terminus of a C–C double bond with an acidic nitrogen nucleophile such as phthalimide. As the terminal …
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Hydroamination of terminal allylic imines, allylic amines, and internal and terminal homoallylic amines: Regioselective and regiodivergent transformations
… and often allows access to two regioisomers (Markovnikov and anti-Markovnikov) from one starting material. 1,2-diamines are a common motif in many organic molecules. However, their synthesis often involves a lengthy, multi-step synthetic sequence. We report the Rh- and Ir-catalyzed addition of …
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Transition metal-catalyzed olefin functionalization for highly regio-, enantio-, and chemoselective C–X bond formation
… larger natural bite angles (βn ≥ 99°) promote a Markovnikov-selective hydrothiolation in up to 88% yield and >20:1 regioselectivity. Conversely, when smaller bite angle ligands (βn ≤ 86°), are employed, the anti-Markovnikov product is formed in up to 74% yield and >20:1 regioselectivity. Initial …
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I. Development of three-component alkene carboamination reactions II. Palladium-catalyzed anti-Markovnikov oxidative amination of alkenes III. Chloroform as a carbon monoxide precursor: in or ex situ generation of co for pd-catalyzed carbonylations IV. Hydroalkylation of alkenes via photoredox catalysis
… broader classes of alkylamine products. The anti-Marknovnikov oxidative amination of alkenes represents a critical regioselectivity gap in the aza-Wacker reaction. We have developed a palladium catalyst capable of promoting a sterically-controlled outer-sphere aminopalladation process to …
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Cross Coupling of Alkenyl Gold Complexes with Alkyl Electrophiles and Nickel Catalyzed Hydroarylation of Alkenes
… of alkenes. We are able to achieve good anti-Markovnikov selectivity with a wide range of alkenes, including styrenes, alkyl substituted alkenes, and enol ethers.
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Rutheniumkatalysierte Hydratisierung von terminalen Alkinen und deren Einsatz in Synthesestrategien
… the context of this work the ruthenium-catalyzed anti-Markovnikon-hydration of terminal alkynes was optimized. This covers the reaction conditions (catalyst loading, concentration, solvent/reaction media, equivalents of water, additives and exchange of the counterion) as well as the variation of …
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Metal-ligand cooperativity in first row transition metals: hydrosilylation catalysis and mechanistic insights
… system CoCl2(iPr2PC3NHpy)/2NaBEt3H gave near quantitative anti-Markovnikov hydrosilylation of 1-octene using Ph2SiH2 after 15 mins with 1 mol% [Co] loading. DFT studies highlighted the redox non-innocence of PNpy, which is possibly relevant to the high catalytic activity observed. In-situ NMR …
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New Pd and Cu-based catalysts for carbon-heteroatom bond formation
… cross-coupling reactions. Part II. Chapter 2. Enantio- and Regioselective Copper-Catalyzed Hydroamination of Styrenes and the Extension of the Methodology towards Anti-Markovnikov Hydroamination of Terminal Aliphatic Alkenes The development of a copper-mediated strategy towards the hydroamination …
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Studien zur intermolekularen Titan-katalysierten Hydroaminierung von Alkinen
… wurde generell die bevorzugte Bildung des Anti-Markovnikov-Produktes beobachtet. Dagegen wurde bei der Addition von Arylaminen an terminale Alkylalkine die Bildung des Markovnikov-Produkts favorisiert. Ferner wurde gezeigt, dass beim Einsatz von enantiomerenreinen alpha�chiralen Aminen in …
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Reactions and rearrangements of chroman-4-ones and related compounds
… ion. Products resulting from aryl migration and anti-Markovnikov addition of acetic acid to the cyclopropane ring are also formed. Carbanions derived from chromanones have been generated and used to prepare a range of 3-hydroxymethylenechroman-4-ones. Conjugate reduction of the corresponding …
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Organic Synthesis: Taming Chemistry using Enabling Technologies
… were an ethylene Heck coupling reaction, an anti-Markovnikov Wacker oxidation and a rhodium-catalysed stereoselective hydrogenation respectively. In addition, a diastereoselective Reformatsky-type carbethoxyallylation using zinc metal was also highlighted in this synthesis to install an …
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Control of regioselectivity:oxidation and deprotection
… studied. The mechanism responsible for this anti-Markovnikov regioselectivity is investigated. Palladium(0) is eliminated as a possible cause of unusual reactivity. NMR studies and reactions of suitable substrates are used to suggest a side-on complex of either an agostic or 4-type. Kinetic …
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The development of directing group enabled hydroamination strategies to access to 1,2-, 1,3-, and 1,4- diamines with high levels of regio-, chemo-, and stereoselectivity
… unresolved challenge for organic chemists. The enantioselective synthesis thereof is more challenging yet, and is generally approached through inefficient and step-intensive approaches such as nucleophilic displacement and resolution. We report the mild Rh-catalyzed enantioselective hydroamination …
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Synthesis and characterisation of small molecule and macromolecular photoredox catalysts for radical thiol-ene reactions
… was reacted with 1- butanethiol, the desired anti-Markovnikov thioether product was formed and this indicated the importance of substrate choice and compatibility with the photoexcited catalyst when designing a photocatalytic system. The reactions carried out using trinuclear complexes (Ered …
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Amphiphile Phosphane für die Anwendung in neuen polaren Medien
… imidazolium phosphines. Base catalyzed Anti-Markovnikov addition of PH functionalized phosphines to the exocyclic double-bond of 1-vinylimidazole allows access to a broard range of mono-, di- and triphosphan ligands with terminal 1-imidazolyl substituents. By selective N-protonation and …
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Neutral and cationic complexes of the rare earth metals : synthesis, characterisation and polymerisation catalysis
… into the Ln–H bond, whilst mixtures of the Markovnikov and anti-Markovnikov products are obtained in the case of styrene. The structural characterisation of the series of Group 13 tri(alkyl) [E(CH2SiMe3)3]n is presented in Chapter B.5. The boron and gallium homologues are monomeric, whilst …
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Zirconium-mediated alkyene-aldehyde coupling, rhodium-catalyzed alkene hydrothiolation, and copper-catalyzed alkyne hydroarylation: Reaction development and mechanistic investigations
… the selectivity for the migratory insertion. The anti-Markovnikov reaction undergoes a Rh–H insertion, followed by Rh–S reductive elimination, while the Markovnikov-selective conditions proceed by Rh–S insertion, followed by Rh–H reductive elimination. The regio- and diastereoselective synthesis …
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A Radical Approach to Photochemical Transformations Using Earth-Abundant Metals
… cooperative LMCT/HAT to achieve a photocatalytic anti-Markovnikov hydrochlorination of unsaturated hydrocarbons. Enabled by selective oxidation of anionic chloride using weakly oxidizing iron to promote LMCT reactivities, previous challenging substrates are tolerated in our protocol, giving high …
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Metal complexes with ω-alkenyl ligands. synthesis, structure, reactivity, and applications in chemical vapor deposition (CVD) and hydrosilylation catalysis
… to form a substituted ƞ3-allyl complex Rh(ƞ3-anti-CH2=CHCHCMe3)(DBCOT). This latter compound subsequently isomerizes in solution to form the thermodynamically more stable isomer Rh(ƞ3-syn-CH2=CHCHCMe3)(DBCOT). Chapter 6 describes the preparation of the …