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Deposited palladium catalysts for C-C bond forming reactions
Semler, Miloslav ; Štěpnička, Petr (advisor) ; Sedláček, Jan (referee)
Palladium based catalysts are widely used for C-C bonding reactions. This work describes the preparation of several such catalysts deposited onto siliceous, SBA-15 type support and common silica gel, whose surface was modified by organic chains with amine donor groups. The prepared catalysts have been tested in coupling reactions of organotin compounds and organic halides (Stille reactions) under various conditions.
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Deposited palladium catalysts
Semler, Miloslav ; Štěpnička, Petr (advisor) ; Balcar, Hynek (referee) ; Bulánek, Roman (referee)
Palladium catalysts are frequently used in C-C coupling reactions. The aim of this work is to prepare several heterogeneous palladium catalysts from comercially available silica gel, each with different bifunctional ligand deposited on the surface of silica gel by N-propylamide linking group, and their testing on several C-C coupling reactions (Heck reaction, reaction of acyl chlorides with boronic acids and reaction of acyl chlorides with terminal acetylenes). Some other aspects of heterogeneous catalysis (such as palladium leaching into the reaction mixture and possibility of catalyst reuse) are discussed, too. Powered by TCPDF (www.tcpdf.org)
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Synthesis and catalytic properties of ferrocenophane phosphines
Škoch, Karel ; Štěpnička, Petr (advisor) ; Veselý, Jan (referee)
6 Title: Sythesis and catalytic properties of ferrocenophane phosphines Author: Karel Škoch Institution: Faculty of Science, Charles University in Prague, Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. Keywords: ferrocene, ferrocenophane, phosphine ligands, palladium, asymetric catalysis, aza- Morita-Baylis-Hillman reaction, asymetric allylic alkylation Abstract: This Thesis describes the preparation of five sterically and electronically different ferrocene phosphines, (R)-1,1'-[1-(diarylphosphino)propan-1,3-diyl]ferrocenes (R)-1a-e, and a study into their coordination and catalytic properties. The key precursor of the phosphine synthesis, chiral alcohol (R)-2, was prepared according to the procedure described in the literature. Alcohol (R)-2 was converted with retention of configuration to diarylphosphines (R)-1a-e in one-step reaction with trimethylsilylchloride and sodium iodide and then with the corresponding diarylphosphine. Phosphines 1a-e were characterized by NMR and MS methods. For the basic representative 1a the following palladium(II) complexes were prepared: [PdCl(LNC )(1a)] (10, LNC = 2-[(dimethylamino)methyl]phenyl-C1 ,N) and trans- [PdCl2(1a)2] (9a). In addition, the isomeric complex cis-[PdCl2(1a)2] (9b) was isolated from the reaction mixture after catalytic...
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Activation of ferrocene ligands by sandwich complexes of Group 4 metals
Kout, Matyáš ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
This bachelor thesis deals with synthesis, reactivity and characterization of compounds resulting from the reactions of substituted ferrocene ligands with electron- deficient complexes of group 4 transition metals in oxidation state II with the aim of finding experimental conditions for preparation of complexes containing two metal atoms in one molecule. Reactions were performed under inert atmosphere and the products were crystallized. The obtained crystals were subjected to X-ray diffraction analysis and to NMR spectroscopy in order to elucidate molecular structure of the isolated products. Along the way, instability of the prepared compounds towards air oxygen and moisture has surfaced, though it also led to a discovery of several original compounds. Among these, the molecule containing peroxide ligand bonded to zirconocene fragment is worth noting as a fine example of oxygen molecule activation with low oxidative state complexes of transition metals.
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Functional phosphinoferrocene carboxamides
Schneiderová, Barbora ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
Functionalized amides 3 and 4 were prepared by the reaction of 1'-(diphenylphosphino)ferrocene-1- carboxylic acid (Hdpf) with 2-(diphenylphosphino) ethylamine or 2-N,N'- (dimethylamino)ethylamine. The amides were converted to their respective phosphinsulfides 5 and 6. Addition of MeI to the solution of 6 gave ammonium salt 7 which, after desulfuration with Raney nickel afforded ammonium salt 8. Compounds 3-8 were characterized by NMR and IR spectroscopy and by MS spectrometry. Phosphine sulfides 6 and polar amides 7 and 8 were structurally characterized. Amides 3, 4 and 8 were tested as ligands in Pd-catalyzed Suzuki-Miyaura coupling reaction of phenylboronic acid with 4-bromacetophenone in organic solvent, water and in biphasic system. Amides 3 and 4 and the related amides 1'-(diphenylphosphanyl)-1-[N-{3- (diphenylphosphino)propyl)}carbamoyl]ferrocene(1) and 1'-(diphenylphosphanyl)-1-[N-(3- dimethylaminopropyl)carbamoyl] ferrocene (2) were reacted with [(COD)PdCl2] to afford palladium complexes of the general formula [(L)PdCl2]. These compounds were characterized by NMR and IR spectroscopy and by MS spectrometry and, for selected representatives, also by X-ray diffraction analysis. Keywords: ferrocene, phosphinoamides, palladium, coordination study, catalysis, Suzuki-Miyaura cross-coupling reaction.
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Homologous ferrocene phosphines
Vosáhlo, Petr ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
Title: Homologous ferrocene phosphines Author: Bc. Petr Vosáhlo Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This thesis describes the synthesis and coordination behaviour of ferrocene diphosphines derived from 1,1'-bis(diphenylphosphino)ferrocene (dppf). Dppf is one of the most succesful ferrocene ligands, which can be used in various metal-catalyzed reactions. This study aimed to prepare analogous ligands with one dialkylphosphino substituent and one (diphenylphosphino)methyl group. These ligands were oxidized by KSeCN to afford the corresponding phosphinoselenides. The phosphinoselenides were used to assess sigma-donor abilities by measuring the coupling constant 1 JSeP via 31 P NMR spectroscopy. Lastly, the coordination behaviour of these ligands in palladium complexes was studied. The homologous ligands usually formed a mixtures containing a chelate complex and dimeric species with trans- coordinated ligands. Key words: ferrocene, phosphines, homologous ligands, palladium(II) complexes, structure elucidation.
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Alternative synthesis of of 1-(diphenylphosphino)-1'-(N,N-dimethylaminomethyl)ferrocene
Zábranský, Martin ; Štěpnička, Petr (advisor) ; Vojtíšek, Pavel (referee)
An alternative, more straightforward and effective method for the preparation of 1- (diphenylphosphino)-1'-(N,N-dimethylaminomethyl)ferrocene was developed using 1-bromo- 1'-(diphenylphosphino)ferrocene as the starting material and Eschenmoser's salt as an aminomethylation agent. Purity of thus prepared phosphinoamine was verified by 1 H and 31 P NMR spectroscopy and by comparison of the data with those reported in the literature (M. E. Wright, Organometallics, 1990, 9, 853). The coordination chemistry of this compound was investigated in gold(I) complexes. Thus, chlorido[1-(diphenylphosphino)-1'-(N,N-dimethyl- aminomethyl)ferrocene]gold(I) complex was synthesized and converted to ill-defined [1- (diphenylphosphino)-1'-(N,N-dimethylaminomethyl)ferrocene]gold(I) perchlorate by halogen abstraction with AgClO4. Protonization of the nitrogen atom in both compounds with hydrogen chloride yielded the corresponding hydrochlorides. It was shown that 1- (diphenylphosphino)-1'-(N,N-dimethylaminomethyl)ferrocene is coordinated as a simple phosphine in the resulting complexes while its amine nitrogen is protonated. All these complexes were characterized by means of 1 H, 31 P and 13 C NMR spectroscopy, mass spectroscopy with electrospray ionisation, elemental analysis and by single-crystal X-ray diffraction analysis.
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Electronically dissymmetric ferrocene bisphosphines
Horký, Filip ; Štěpnička, Petr (advisor) ; Horáček, Michal (referee) ; Šebesta, Radovan (referee)
This Thesis describes the synthesis, reactivity, coordination properties, and catalytic activity of novel electronically dissymmetric bisphosphines structurally related to 1,1'-bis(diphenylphosphino)ferrocene (dppf). First, a methylene spaced congener containing a primary phosphine group, which is stable in the air, Ph2PfcCH2PH2 (fc = ferrocene-1,1'-diyl), was prepared. While studying its reactivity, an unprecedented stable primary phosphine oxide, Ph2PfcCH2P(O)H2, was isolated. The primary phosphine, the corresponding phosphine oxide, dppf and the known bis-tertiary phosphine Ph2PfcCH2PPh2 were studied as ligands in Ru(II) complexes. The catalytic activity of the defined complexes was compared in two ruthenium-catalyzed reactions: cyclization of (Z)-3-methylpent-2-en-4-yn-1-ol into 2,3-dimethylfuran and isomerization of estragole to anethole. Second, the remarkable stability of the prepared primary phosphine oxide called for a detailed investigation of this poorly described class of compounds. As a result, stable primary phosphine chalcogenides lacking steric protection FcCH2P(Y)H2 (Fc = ferrocenyl; Y = O, S, Se) were isolated for the first time. These compounds were studied as ligands in reactions with hard and soft Lewis acids (Zn(II) and Ru(II)), and the reactivity of the P-H hydrogens was...
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Reactivity of a ferrocene distibane
Antala, Jakub ; Štěpnička, Petr (advisor) ; Gyepes, Róbert (referee)
5 Title: Reactivity of ferrocene distibane Author: Jakub Antala Department: Department of Inorganic Chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Consultant: RNDr. Jiří Schulz, Ph.D. Abstract: The aim of this bachelor thesis is preparation of 1,1'-bis(diphenylstibino)ferrocene (L), an antimony analogue of the widely studied ligand 1,1'-bis(diphenylphosphino)ferrocene and study into its coordination properties. Two ruthenium(II) (1, 3) and two rhodium(III) complexes (2, 4) were prepaired, in which the ligand L coordinates as bridging or chelating ligand. Two ruthenium(II) and one rhodium(III) precursors with π-coordinated arene ligands were used for the preparation of complexes. When preparing chelate complexes, sodium hexafluorophosphate was also necessary. All complexes were characterised by NMR spectroscopy, mass spectrometry, elemental analysis and crystal structure was determined by X-ray structural analysis. The structures of the stibine complexes were compared with their analogs resulting from 1,1'-bis(diphenylphosphino)ferrocene. Key words: ferrocene, stibines, complexes, ruthenium, rhodium, structure elucidation
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