National Repository of Grey Literature 4 records found  Search took 0.00 seconds. 
Electrochemical Study of Selected Pyrene Derivatives as Precursors to Organic Semiconductors
Koláčná, Lucie ; Tobrman, T. ; Ludvík, Jiří
A series of 9 precursors for pyrene based biodegradable organic (semi)conductors having tetrasubstituted double bond as a central organic core and photo- or redox active centers attached at this core were electrochemically investigated in order to determine the influence of individual parts of the molecule on the redox properties, to describe the location of the reduction center and to understand the structure - redox activity relationship of the mentioned compounds.
New C-H activations and cross-coupling reactions for modification of deazapurine nucleobases
Sabat, Nazarii ; Hocek, Michal (advisor) ; Tobrman, Tomáš (referee) ; Hlaváč, Jan (referee)
This PhD thesis reports the development of novel C-H activation strategies and aqueous-phase Suzuki-Miyaura cross-coupling reactions for the synthesis of modified deazapurine nucleobases. The methodologies of chemo- and regioselective synthesis of highly functionalized deazapurines have been developed by using modern C-H activation chemistry. Various functional groups such as amino-, imido-, silyl- and phosphonyl- were introduced by C-H activation reactions. Amino deazapurine derivatives were synthesized by developed Pd/Cu-catalyzed direct C-H amination and C-H chloroamination of 6-substituted 7-deazapurines with N-chloro-N- alkyl-arylsulfonamides. C-H imidation reactions of pyrrolopirimidines were performed under ferrocene catalysis with N-succinimido- or N-phtalimidoperesters. In order to obtain silylated derivatives, Ir-catalyzed C-H silylations of phenyldeazapurines with alkyl silanes were designed. Highly interesting deazapurine phosphonates were prepared by using Mn-promoted C-H phosphonation method and were further transformed into the corresponding phosphonic acids. All of the developed direct C-H functionalization reactions proceeded regioselectively at position 8 in deazapurine core, except for C-H silylation where reaction undergoes mainly as directed ortho C-H silylation on phenyl ring,...
Cyclotrimerization of alkynes and nitriles in the synthesis of helically chiral compounds
Klívar, Jiří ; Stará, Irena (advisor) ; Tobrman, Tomáš (referee)
The objective of this Thesis was to prepare dialkynenitriles 156 and 168 for the synthesis of aza[6]helicene 146 and 147 via intramolecular [2+2+2] co-cyclotrimerization. It was found that it is possible to use co-cycloisomerization of alkynedinitriles 182, 187, 192 and 195, a reaction so far not described in the literature, for the preparation of dibenzodiazahelicenes 148 and 149 and dioxadiazahelicenes 150 and 151 possessing a pyridazine subunit. Moreover, alkynedinitriles 152, 153, 154 and 155 were synthesized to further study of this co-cycloisomerization reaction. The Theoretical Part outlines some representative examples of methods for the preparation of azahelicenes and azoniumhelicenes, current development of [2+2+2] cocyclotrimerization in the synthesis of pyridine derivatives and methods of pyridazine synthesis. The syntheses of dialkynenitriles 156 a 168, diazahelicenes 148, 149, 150, 151 and alkynedinitriles 152, 153, 154 and 155 are described in the section Results and Discussion and Experimental Part.
The Combination of Organometallic, Transition-Metal Catalyzed, Radical and Carbocationic Reaction Steps to Domino Processes
Jagtap, Pratap Ramling ; Jahn, Ullrich (advisor) ; Tobrman, Tomáš (referee) ; Bureš, Filip (referee)
This work deals with the development of methodology, which couples reactive intermediates of varying oxidation states, in tandem sequences comprising 1,2-organometallic addition/transition metal catalyzed isomerization/Michael addition/SET oxidation/radical cyclization/oxygenation steps in the synthesis of highly functionalized carbocycles. Implementation of this sequence being catalytic in the SET oxidant was studied. 1,4-Diketones were synthesized in a tandem 1,2-addition/ruthenium-catalyzed redox isomerization/enolates oxidation/radical dimerization reaction and results were compared with 1,4-diketones formation via oxidative coupling of ketone enolates. The total synthesis of selective tetrahydrofuran lignans from 1,4-diketones obtained in a tandem addition/isomerization/dimerization reaction is also documented

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