- Reactions of coordinated hydroxymethylphosphines with NH-functional amines: The phosphorus lone pair is crucial for the phosphorus Mannich reaction
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Non-coordinated hydroxymethylphosphines react readily with primary and secondary amines by the phosphorus Mannich reaction. To determine if this reactivity can be used to synthesize phosphine macrocycles, trans-Fe(DHMPE) 2Cl2 (DHMPE = 1,2-bis(dihydroxymethylphosphino)ethane) was prepared and reacted with various amines. However, no phosphorus Mannich reactivity was observed. In order to understand why no reactions occurred, the Mannich reactivity of the borane-coordinated hydroxymethylphosphines DHMPE·2BH3 and Ph2PCH2OH·BH 3 was investigated. These borane-coordinated phosphines also did not undergo the phosphorus Mannich reaction. These results suggest that the lone pair of electrons on the phosphorus atom is essential for the phosphorus Mannich reaction to occur, and therefore it is not possible to use this reaction in a templated synthesis of phosphine macrocycles. It is speculated that the mechanism of the phosphorus Mannich reaction may involve a methylenephosphonium intermediate, analogous to an iminium in the standard Mannich reaction. X-ray crystal structures of trans-Fe(DHMPE)2Cl2 and DHMPE·2BH3 are also presented. Both crystal structures display an extended hydrogen-bonding network in the solid state. The Royal Society of Chemistry 2011.
- Swor, Charles D.,Hanson, Kyle R.,Zakharov, Lev N.,Tyler, David R.
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- Two out of Three Musketeers Fight against Cancer: Synthesis, Physicochemical, and Biological Properties of Phosphino CuI, RuII, IrIII Complexes
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Two novel phosphine ligands, Ph2PCH2N(CH2CH3)3 (1) and Ph2PCH2N(CH2CH2CH2CH3)2 (2), and six new metal (Cu(I), Ir(III) and Ru(II)) complexes with those ligands: iridium(III) complexes: Ir(η5-Cp*)Cl2 (1) (1a), Ir(η5-Cp*)Cl2 (2) (2a) (Cp*: Pentamethylcyclopentadienyl); ruthenium(II) complexes: Ru(η6-p-cymene)Cl2 (1) (1b), Ru(η6-p-cymene)Cl2 (2) (2b) and copper(I) complexes: [Cu(CH3CN)2 (1)BF4 ] (1c), [Cu(CH3CN)2 (2)BF4 ] (2c) were synthesized and characterized using ele-mental analysis, NMR spectroscopy, and ESI-MS spectrometry. Copper(I) complexes turned out to be highly unstable in the presence of atmospheric oxygen in contrast to ruthenium(II) and iridium(III) complexes. The studied Ru(II) and Ir(III) complexes exhibited promising cytotoxicity towards cancer cells in vitro with IC50 values significantly lower than that of the reference drug—cisplatin. Con-focal microscopy analysis showed that Ru(II) and Ir(III) complexes effectively accumulate inside A549 cells with localization in cytoplasm and nuclei. A precise cytometric analysis provided clear evidence for the predominance of apoptosis in induced cell death. Furthermore, the complexes presumably induce the changes in the cell cycle leading to G2/M phase arrest in a dose-dependent manner. Gel electrophoresis experiments revealed that Ru(II) and Ir(III) inorganic compounds showed their unusual low genotoxicity towards plasmid DNA. Additionally, metal complexes were able to generate reactive oxygen species as a result of redox processes, proved by gel electrophoresis and cyclic voltamperometry. In vitro cytotoxicity assays were also carried out within multicellular tumor spheroids and efficient anticancer action on these 3D assemblies was demonstrated. It was proven that the hydrocarbon chain elongation of the phosphine ligand coordinated to the metal ions does not influence the cytotoxic effect of resulting complexes in contrast to metal ions type.
- Barzowska, Agata,Bieńko, Alina,Caramori, Stefano,Komarnicka, Urszula K.,Kozie?, Sandra,Kyzio?, Agnieszka,Lesiów, Monika,Niorettini, Alessandro,Porchia, Marina,Pucelik, Barbara,Wojtala, Daria,Zió?kowska, Aleksandra
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- Phosphonium bis(glycolates) and phosphinoglycolates: Synthesis, solvolysis, oxidation to (thio)phosphinoylglycolates and use as ligands in Ni-catalyzed ethylene oligomerization
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Secondary phosphines, glyoxylic acid hydrate and amines react to form organoammonium phosphonium bis(glycolates) 1a-d. In CD3OD solution, diphenylphosphonium bis(glycolates) undergo reversible solvolysis to phosphinoglycolates 2a,b and acetalic glyoxylic species. The P-dialkyl species 1c avoids this and maintains the phosphonium bis(glycolate) structure in CD 3OD (cHex2P) or undergoes further solvolysis with partial formation of R2PH (R = tBu). Condensation to phosphinoglycines, e.g. 3b, observed for primary amines, does not take place with N-secondary amines at room temperature. Heating leads to condensation but is followed by decarboxylation as shown for the conversion of 2a to 4a. Because of the kinetic lability, the phosphonium compounds 1a-d are sensitive to oxidation by air, H2O2, or sulfur. The resulting phosphinoyl and thiophosphinoyl glycolates and glycolic acids 5-8 are kinetically stable. Precatalyst solutions formed from 1a, c, d and Ni(COD)2 in THF developed moderate to good activity in the oligo- or polymerization of ethylene to linear products containing methyl and vinyl end groups. Activity and molecular weights increased with the +I-effect of the P-substitutents. The solution structures of the novel compounds were elucidated by multinuclear NMR spectroscopy. For 7a a crystal structure analysis is also presented.
- Peulecke, Normen,Kindermann, Markus K.,K?ckerling, Martin,Heinicke, Joachim
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- Process for the preparation of a butene
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Process for the preparation of 1-butene by dimerization of ethylene in the presence of an aprotic solvent and a catalytic system prepared by combining (a) a Pd compound, (b) an anion of an acid having a pKa = 1 N atoms which atoms bear no H atoms and in which compound each N atom is connected to the P atom by an organic bridging group containing >= 1 C atom in the bridge.
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