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.
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Showing 1 to 12 of 12 for “"transition metal-free"”.
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Development of Novel, Regioselective Borylation Protocols
… synthesis has been geared heavily toward transition metal-catalyzed addition to double and triple bonds, though an increasing number of publications detail transition metal-free borylation techniques involving substrate-mediated activation of a diboron reagent. This dissertation describes …
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Greener Photoredox-Catalyzed Phosphonations of Aryl Halides
… pose incredible environmental concerns. Milder, transition metal-catalyzed approaches have been developed, but can be limited by air sensitivity, cost, low reaction selectivity, and low functional group compatibility. Photoredox catalysis has been significantly advanced in the past decade in the …
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Chemoselective and Stereoselective Exploration of the Chemical Reactivity Space of Castagnoli-Cushman-Derived Allylic Lactamoyl Esters: Application to the Synthesis of Aza-Polycyclic Architectures
… example of a hydroamino alkylation that is transition metal-free and occurs at room temperature will also be discussed.
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Modular Synthesis and Hydroalkylation of Vicinally Functionalized Ketopiperazines: A solution to the Piperazine Problem
… describe a step-economical-, cost-effective-, transition metal-free-, and mild approach to highly functionalized piperazines, including [3.3.1]-bicyclic piperazines. The success of a novel enolate hydroalkylation methodology hinges on a cascade reaction triggered by the addition of allyl …
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Cascade Annulation and Ring-Opening Reactions of Castagnoli-Cushman-Derived Allylic and Benzylic Thiomorpholinonates
… cost- and time-efficient. In this embodiment, a transition metal-free, base-mediated cascade reaction featuring methylesterification of allylic thiomorpholinonyl acids and concomitant regioselective intramolecular hydroalkylation is described. The method hinges on the <em>in-situ</em> generation …
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Regio- and Stereo- selective Methods for the Borylation of Substituted Alkynes
… addition pathway. We also developed a transition metal-free cis hydroboration of 1,3-diyne substrates. In the presence of catalytic amounts of tri-n-butylphosphie and the unsymmetric diboron reagent pinBBdan, 1-boryl-1,3-enyne products were generated in up to 63% and >99:1 …
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Boron-Mediated Semireduction of Alkynoic Acid Derivatives
… of internal alkynes, a process dominated by transition metals and often results in incomplete (E)-stereoselectivity. This dissertation describes three novel uses of a diboron reagent or pinacolborane that reduce propiolic acid derivates selectively to (E)-alkenes and one method that installs …
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Photoredox C–C Cross-Coupling Reactions using Boronic Acid Derivatives
… on developing an efficient flow process and “transition metal free” conditions to survey the attractiveness of the method for the pharmaceutical industry. Finally, the fifth chapter describes the experimental procedures relevant to the results described in chapters 2 to 4.
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Development of Methods for Boron Reagents
… evidence. Finally, Chapter 3 describes a transition-metal-free trans hydroboration of alkynoate esters and amides. The reaction is phosphine-catalyzed and proceeds with pinacolborane to afford (E)-beta-borylacrylates and (E)-beta-borylacrylamides in good to excellent yields. The reaction …
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Generation of Alkyl Radicals Via C-H Functionalization and Halogen Atom Transfer Processes
… in this field, some methods still require costly transition metal catalysts or toxic reagents. Herein, we display a series of visible light-induced approaches under transition-metal free conditions or using earth-abundant metals. These novel photo-induced transformations and corresponding …
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Novel reaction discovery with rapid high-throughput experimentation via infrared spectroscopy and enzymatic electrochemical oxidation of alcohols
… component in the highly enantioselective, transition-metal-free Petasis reaction.
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Trans Addition of B-X Reagents Across Polarized Triple Bonds and Development of Sphingosine-1-Phosphate Transport Inhibitors
… methods rely on the use of expensive and toxic transition-metal catalysts. Herein, we describe the development of trans addition of boron reagents across polarized triple bonds to afford novel vinylboronic acids. Emphasis is placed on the transition metal-free nature of the reactions as well as …