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Transition metal catalyzed cross-coupling reactions of onium salts
Hidasová, Denisa ; Šrogl, Jiří (advisor) ; Drahoňovský, Dušan (referee)
The research of this thesis is focused on developing Suzuki cross-coupling reactions of various onium salts using the catalytic system Ni complex/trans-N,N'-dimethyl-1,2- cyklohexanediamine. As an expansion in the catalysis of nickel compounds, we have established that the catalytic system Ni(cod)2/trans-N,N'-dimethyl-1,2-cyklohexanediamine can affect Suzuki reactions of tetramethylenesulfonium salts with boronic acid, which leads to cleavage of C-S and formation of new C-C bonds under relatively mild reaction conditions. This explains the unique reactivity and biomimetic behavior of a nickel catalyst to activate the C-S bond. Key words: onium salts, Suzuki coupling, nickel complexes
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Asymmetric Tandem Lithium Amide Conjugate Addition/Radical Reactions and Their Application in the Total Synthesis of Natural Products
Hidasová, Denisa ; Jahn, Ullrich (advisor) ; Kočovský, Pavel (referee) ; Míšek, Jiří (referee)
This thesis deals with single-electron transfer (SET) radical processes mediated by ferrocenium hexafluorophosphate and TEMPO and their application in the total synthesis of natural products. Asymmetric aminooxygenation methodology for the synthesis of anti-β-amino-α-hydroxy acid derivatives has been developed by utilizing a highly diastereoselective aza-Michael addition of chiral lithium amides to various α,β-unsaturated esters or amides/SET oxidation/radical α-oxygenation. The potential of this methodology was demonstrated in short total syntheses of the anti-β-amino-α-hydroxy acid fragments of the macrocyclic (depsi)peptides perthamide C and largamide H, and (-)-cytoxazone, which is a selective modulator of TH2 cytokine secretion. The SET-catalyzed asymmetric tandem lithium amide conjugate addition/5-exo radical cyclization/oxygenation reactions were applied in the synthesis of highly substituted pyrrolidines, azabicyclo[n.3.0]alkanes and spiropyrrolidines. An enantioselective total synthesis of the pyrrolidine alkaloid (-)-α-kainic acid was accomplished by employing the SET-catalyzed 5-exo radical cyclization/oxygenation.
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Transition metal catalyzed cross-coupling reactions of onium salts
Hidasová, Denisa ; Šrogl, Jiří (advisor) ; Drahoňovský, Dušan (referee)
The research of this thesis is focused on developing Suzuki cross-coupling reactions of various onium salts using the catalytic system Ni complex/trans-N,N'-dimethyl-1,2- cyklohexanediamine. As an expansion in the catalysis of nickel compounds, we have established that the catalytic system Ni(cod)2/trans-N,N'-dimethyl-1,2-cyklohexanediamine can affect Suzuki reactions of tetramethylenesulfonium salts with boronic acid, which leads to cleavage of C-S and formation of new C-C bonds under relatively mild reaction conditions. This explains the unique reactivity and biomimetic behavior of a nickel catalyst to activate the C-S bond. Key words: onium salts, Suzuki coupling, nickel complexes
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