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1	Organocatalytic Acylation for the Kinetic Resolution of Secondary Aryl Alcohols : Synthetic Applications and Mechanistic Studies Mesas Sánchez, Laura January 2014 (has links) The research described in this thesis focuses on the catalytic acylative kinetic resolution (KR) of aromatic secondary alcohols, using a planar-chiral 4-(dimethylamino)pyridine (DMAP) organocatalyst. In the first part of this thesis, the substrate scope of the above mentioned process was expanded to aromatic secondary alcohols that contain an extra functional group in the alkyl moiety, such as 1,2-azido alcohols, 2-hydroxy-2-aryl-ethylphosphonates and 2-hydroxy-2-aryl esters. Thus, the preparation of highly functionalized compounds in their enantiomerically pure form with excellent enantiomeric excess (up to 99% ee) was achieved. Furthermore, the synthetic applicability of this methodology was illustrated through the synthesis of two high value compounds, (R)-Pronethalol and (S)-3-hydroxy-N-methyl-3-phenylpropanamide, which is an immediate precursor of bioactive molecules such as (S)-Fluoxetine. The second part of this thesis deals with the mechanistic study of the acylative KR catalyzed by the planar-chiral DMAP derivative. Reaction Progress Kinetic Analysis methodology was used in the investigation of the reaction mechanism, probing that no notable product inhibition or decomposition of the catalyst occurs in the studied system. The reaction rate showed fractional order dependence on the concentration of both reactants. Furthermore, NMR spectroscopy was utilized to study the equilibrium between the different catalyst states, which explains the measured kinetics of the reaction. kinetic resolution organocatalysis secondary alcohols reaction progress kinetic analysis
2	C<sub>2</sub>-Symmetric Pyrazole-Bridged Ligands and Their Application in Asymmetric Transition-Metal Catalysis Böhnisch, Torben 23 July 2015 (has links) No description available. 540 Pyrazole-Bridged Ligands Asymmetric Transition-Metal Catalysis Cooperative Asymmetric Catalysis Enantioselective Catalysis Two-Center Catalysis Pyrazole PyrBOX PyrBPyBOX ProPyrazole Tsuji-Trost Allyl Palladium Asymmetric Allylic Substitutions Asymmetric Allylic Alkylations Solvation Effects Cooperative Effects EXSY Helicate Mesocate Cluster Helicate Atropisomerism Atropselective Oxidative Coupling 2-Napthol Chemie (PPN62138352X)

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Organocatalytic Acylation for the Kinetic Resolution of Secondary Aryl Alcohols : Synthetic Applications and Mechanistic Studies

C<sub>2</sub>-Symmetric Pyrazole-Bridged Ligands and Their Application in Asymmetric Transition-Metal Catalysis