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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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Preparation of ruthenium complexes bearing ibuprofene derivatives
Ráliš, Václav ; Štěpnička, Petr (advisor) ; Schulz, Jiří (referee)
Charles University in Prague Faculty of Science Department of inorganic chemistry Author: Václav Ráliš Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Consultant: Mgr. Jiří Pinkas, Ph.D Title: Preparation of ruthenium complexes bearing ibuprofene derivatives Cp* arene complexes of ruthenium with the general formula [(η6 -arene)RuCp*]X (where Cp* is pentamethylcyclopentadienyl and X is an anion in the outer sphere) have recently been the subject of the development of new anticancer drugs. The aim of this thesis was to prepare two new compounds bearing ibuprofen (ibuprofen as a racemic mixture). Two synthetic procedures were chosen for the attachment of ibuprofen, by η6 -bond and also by ester bond to the complex [(η6 -BnOH)RuCp*]Cl (3), where Bn is benzyl. The complex [(η6 -ibuprofen)RuCp*]PF6 (1HPF6) was prepared. The zwitterionic form of this complex [(η6 -ibuprofen- )RuCp*] (1) showed unexpected decarboxylation, yielding the complex [(η6 -1-ethyl-4-isobutylbenzene)RuCp*]HCO3 (2). To the best of our knowledge this kind of reaction has never been described before for this type of compounds. The complex [(η6 -BnOibuprofen)RuCp*]Cl (4) was prepared by reacting ibuprofen acyl chloride with the complex 3. Prepared complexes were characterized via 1 H, 13 C{1 H} NMR, IR spectroscopy, ESI-MS+ and melting...
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Ferrocene phosphinoguanidine donors
Bárta, Ondřej ; Štěpnička, Petr (advisor) ; Dostál, Libor (referee) ; Hoskovcová, Irena (referee)
The "Ferrocene phosphinoguanidine donors" project presented in this Thesis targeted on the synthesis, coordination chemistry and catalytic applications of a rather uncommon class of compounds combining phosphine and guanidine functional groups in their molecules. Two series of such compounds based on ferrocene backbone (henceforth fc = ferrocen-1,1΄-diyl) were studied. Firstly, a reliable synthetic route towards polar phosphinoguanidinium chlorides [R2PfcCH2NHC(NH2)2]Cl, where R = iso-propyl, cyclohexyl, phenyl and 2-furyl, was developed and these ligands were tested as supporting ligands in palladium-catalysed Suzuki-Miyaura-type reactions in biphasic aqueous mixtures and in rhodium-catalysed hydroformylation of 1-hexene. Deduced from the results, the hydrophilic guanidinium tag had a beneficial effect on the catalytic activity and, particularly, the electron-rich phosphines from this series could serve as a useful alternative to commonly used ligands for catalytic applications in polar or aqueous reaction media. Phosphinonitriles R2PfcCN obtained as intermediates during the synthesis of the abovementioned ligands were additionally used for the preparation of the dimeric complexes [Au2(µ-R2PfcCN)2][SbF6]2, in which the gold(I) centre was stabilised by nitrile coordination. These complexes proved...
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Synthesis and characterization of a phosphinoferrocene ligand modified by an amidosulfonate substituent
Varmužová, Věra ; Štěpnička, Petr (advisor) ; Gyepes, Róbert (referee)
Title: Synthesis and characterization of a phosphinoferrocene ligand modified by an amidosulfonate substituent Author: Věra Varmužová Department: Department of Inorganic chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D., DSc. Abstract: This bachelor thesis describes the synthesis of a new compound, 1-(diphenylphosphino)-1'-(methylsulfonamino)ferrocene (compound 2), from 1,1'-dibromoferrocene. Compound 2 was prepared by reaction of 1-(diphenylphosphino)-1'-aminoferrocene-borane (1: 1) with methanesulfonyl chloride in the presence of pyridine, followed by deprotection of the diphenylphosphine group. The conditions of the reaction were optimised so that the reaction was performed with complete consamption of the starting material. The synthesis proceeds via 1-(diphenylphosphino)-1'- (methylsulfonamino)ferrocene-borane (1: 1) (compound 2), which is also a new compound. Both compounds were characterised by nuclear magnetic resonance, mass spectroscopy, infrared spectroscopy, elemental analysis and their crystal structure was determined by single- crystal X-ray crystallography. Key words: ferrocene, phosphines, sulfonamides, synthesis.
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Synthesis and coordination properties of phosphinoguanidine ligands
Leitner, Zdeněk ; Štěpnička, Petr (advisor) ; Gyepes, Róbert (referee)
Title: Synthesis and coordination properties of phosphinoguanidine ligands Author: Zdeněk Leitner Department: Department of Inorganic chemistry Supervisor: prof. RNDr. Petr Štěpnička, Ph.D. DSc. Abstract: The aim of this work was the preparation and characterisation of a hybrid P,N-donor ligand, 2-(2-(diphenylphosphanyl)phenyl)-1,3-diisopropylguanidine (compound 2), containing a polar guanidine moiety. Potential use of this ligand lies in the preparation of catalytically active complexes with a possible change of distribution between organic and water phase upon altering pH. Firstly, synthesis of the starting materiál, (2-aminophenyl)diphenylphosphine, by copper(I)- catalysed P-C coupling reaction was optimized, up to 88% yield. Preparation of compound 2 was optimized as well. Salt 4 was prepared by protonation of 2. In order to evaluate basicity of phosphine groups in the structure of 2 and 4 and an impact of guanidine moiety protonation, corresponding selenides 3 and 5 were prepared and the 1 JPSe were measured. Ligand 2 was prepared by addition of (2-aminophenyl)diphenylphosphine across 1,3-diisopropylcarbodiimide. Selenide 3 was obtained from eaction of 2 with KSeCN. Salts 4 and 5 were prepared by neutralizing compounds 2 and 3 with hydrochloric acid. All novel compounds were characterized by 1...
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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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Polar phosphinoferrocene ligands with hydrocarbyl bridges
Zábranský, Martin ; Štěpnička, Petr (advisor) ; Dostál, Libor (referee) ; Šebesta, Radovan (referee)
A new synthetic route towards methylene-spaced hybrid phosphinoferrocene ligands was developed, making use of a phosphinoferrocene betaine 3-(N,N,N-{[1'-(diphenylphosphino)- ferrocenyl]methyl}dimethylammonium)propane-1-sulfonate (2), that is readily accessible from 1-(diphenylphosphino)-1'-(N,N-dimethylaminomethyl)ferrocene (XIX) via treatment with 1,3-propanesultone. The betaine 2 was reacted with sodium alkylsulfinates (alkyl = methyl, phenyl, 4-tolyl) to afford the corresponding sulfones 4. The coordination chemistry of [1'-(diphenylphosphino)ferrocenyl]methyl(methyl)sulfone (4a) was investigated in its zinc(II) complexes. Surprisingly, only insoluble mixed-metal coordination polymers of the general formula [MZnX3(4a)(MeOH)]n (M/X = Na/Br, K/Br, Na/I) and six-centre complex [Li2Zn2Br6(4a)2(MeOH)4(H2O)] could be obtained. Two isomeric homologues of 1'-(diphenylphosphino)ferrocene-1-carboxylic acid (Hdpf, II), viz. 1'-(diphenylphosphino)ferrocenylacetic acid (HIIa) and 1'- [(diphenylphosphino)methyl]ferrocene-1-carboxylic acid (HIIb), were prepared and their coordination preferences were assessed in their palladium(II) complexes. The palladium(II) complexes were prepared by reacting various (acetylacetonate)palladium(II) precursors with these acids with concomitant release of acetylacetone....
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Synthesis and coordination behaviour of 3-(diphenylphosphino)propanamide
Řežábková, Jana ; Štěpnička, Petr (advisor) ; Havlíček, David (referee)
This bachelor thesis describes the synthesis of 3-(diphenylphosphino)propanamide (compound 1) and subsequent preparation of two palladium(II) complexes with the synthesized phosphinoamide ligand. The coordination behaviour of 3-(diphenyl- phosphino)propanamide is discussed. In complex [PdCl(LNC )(Ph2PCH2CH2C(O)NH2-κP)] (compound 2) the phosphinoamide 1 exhibits P-monodentate coordination, whereas in the cationic complex [Pd(LNC )(Ph2PCH2CH2C(O)NH2-κ2 O,P)]ClO4 (compound 3) it binds as a P,O-chelating bidentate ligand. (LNC = 2-[(dimethylamino-κN)methyl]phenyl-κC1 ). 1 2 3 The ligand was synthesized by base-catalysed addition of diphenylphosphine across the double bond of acrylamide. Both complexes were prepared from [PdCl(LNC )]2 as metal precursor. All substances were characterised by common analytical methods, specifically by NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analysis. Crystals of both complexes were obtained and their crystal structure was determined using X-ray crystallography.
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