Sökning: "carbon-carbon bond formation"

Visar resultat 1 - 5 av 18 avhandlingar innehållade orden carbon-carbon bond formation.

1. 1. New Reactions with Allyl- and Allenylboron Reagents : Transition-Metal-Catalyzed and Transition-Metal-Free Carbon-Carbon Bond Formation Processes

   Författare :Dong Wang; Kálmán J. Szabó; Jianbo Wang; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; carbon-carbon bond formation; cross-coupling; organoboron compound; allylboron reagent; allylation; transition metal; metal carbene; allenylboron reagent; transition metal free; diazo compound; tosylhydrazone; quinone; organisk kemi; Organic Chemistry;

   Sammanfattning : Organoboron compounds have been widely used in carbon-carbon bond formation reactions in organic synthesis and catalysis. This thesis is focused on cross-coupling reactions of allyl-, allenylboronic acids and their ester derivatives via transition metal catalysis or transition-metal-free processes. LÄS MER

3. 2. Carbon-Carbon Bond Formation via Radical Cyclization and Transition Metal Catalysis

   Författare :Puneet Srivastava; Lars Engman; Ullrich Jahn; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Radical cyclizations; transition metal catalysis; Chemistry; Kemi; Chemistry with specialization in Organic Chemistry; Kemi med inriktning mot organisk kemi;

   Sammanfattning : Free radical cyclization methodology has been used extensively in synthesis for manipulation of complex molecules such as alkaloids, terpenes, carbohydrates, peptides and nucleic acids. The methodology has emerged as a result of work by physical organic chemists who determined rate constants for the most common radical reactions used in organic synthesis. LÄS MER

4. 3. Transition metal-catalysed isomerisation of allylic alcohols : Applications to C−C, C−F and C−Cl bond formation

   Författare :Nanna Ahlsten; Belén Martín-Matute; M. J. Jonathan Williams; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; transiton metal-catalysis; allylic alcohols; isomerisation; halogenation; organisk kemi; Organic Chemistry;

   Sammanfattning : The focus of this thesis has been to develop selective and atom-economical methods for carbon-carbon and carbon-heteroatom bond formation, and to some extent improve on existing findings in this area. More specifically, methods for the catalytic generation of enolates from allylic alcohols and their in situ functionalisation with electrophilic reagents are described. LÄS MER

5. 4. The synthesis of chiral bidentate (N,N), (N,P) and (N,O) ligands and their use in metal-mediated asymmetric carbon-carbon bond formation

   Författare :Fredrik Johansson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Chemistry; Kemi; organisk kemi; Organic Chemistry;

   Sammanfattning : This thesis covers three projects based on the metal-mediated formation of new chiral centers in the prescence of chiral ligands. The first project, involving (N,N)- ligands, concerns the synthesis of some (C2-symmetric bis(aziridine) ligands and the use of these in the addition of organolithium reagents to N-aryl protected imines leading to enantioselectivities of up to 89%. LÄS MER

7. 5. Samarium(II)-mediated Reactions in Organic Synthesis - Method Development and Mechanistic Investigation

   Författare :Tobias Ankner; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Samarium II iodide; reduction; single electron transfer; nitro group reduction; mechanistic study; bond cleavage; deoxygenation; additives; toluenesulfonyl deprotection; defluorination.;

   Sammanfattning : This thesis describes the development of methods using divalent samarium reagents in organic synthesis. The main focus is placed on functional group reductions, but reductive formation of carbon-carbon bonds has also been investigated. LÄS MER