Sökning: "Bond"

Visar resultat 26 - 30 av 969 avhandlingar innehållade ordet Bond.

1. 26. Formation and Decomposition of Platinum–Thallium Bond, Kinetics and Mechanism. Structural Characterization of Some Metal Cyanides in the Solid State

   Författare :Péter Nagy; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; metal–metal bond; platinum; thallium; kinetics; mechanism; stopped flow; oxidative addition; cyano complexes; edta; redox reaction; metal cyanides; X–ray diffraction; Raman; NMR; mercury; palladium; nickel; one dimensional wire;

   Sammanfattning : The kinetic and mechanistic features of a new series ofplatinum-thallium cyano compounds containing a direct andunsupported by ligands metal-metal bond have been studied insolution, using standard mix–and–measurespectrophotometric technique and stopped–flow method.These reactions are interpreted as oxidative addition of the cspecies to the square planar Pt(CN)42-complex. LÄS MER

3. 27. Lanthanide-mediated C-F Bond Activation Method Development and Mechanistic Investigation

   Författare :Mario Janjetovic; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; C-F bond activation; fluorine chemistry; lanthanides; single-electron transfer reagent; Lewis acid; chemoselectivity; synthetic method; catalysis;

   Sammanfattning : The use of transition-metals and main-group Lewis acids has proven to be an outstanding source for activation and subsequent functionalization of fluorinated compounds. However, the first is mainly limited to C(sp2)–F bonds which partially are activated by an adjacent heteroatom, and the latter is limited to simple C(sp3)–F bonds due to particularly strong Lewis acid character. LÄS MER

4. 28. 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

5. 29. Novel strategies for C-C/X bond formation

   Författare :Prasad Anaspure; Ian A. Nicholls; Suppan Kathiravan; Jesper G. Wiklander; Subramanian Suriyanarayanan; Yannick Landais; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; annulation; C-H activation; heterocycles; heterogeneous catalysis; homogeneous catalysis; lab-on-a-chip; Suzuki cross-coupling; Organic Chemistry; Organisk kemi;

   Sammanfattning : The formation of C-C/X bonds is essential for the manufacture of a broad range of chemicals and materials used in areas critical for maintaining quality of life in modern society, e.g. pharmaceuticals, agrochemicals and polymers, and for aspects of research in organic chemistry. LÄS MER

7. 30. 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