- Synthesis of Phosphanylferrocenecarboxamides Bearing Guanidinium Substituents and Their Application in the Palladium-Catalyzed Cross-Coupling of Boronic Acids with Acyl Chlorides
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Phosphanylferrocene donors bearing polar guanidinium substituents, namely acylguanidinium chloride, [Ph2PfcCONHC(NH2)NH2]Cl (1), and amidoguanidinium chloride, [Ph2PfcCONHCH2CH2NHC(NH2)NH2]Cl (2; fc = ferrocene-1,1′-diyl), have been prepared and characterized. As functional phosphane donors, they were employed in the synthesis of PdIIcomplexes bearing 2-[(dimethylamino)methyl-κN]phenyl-κC1(LNC) and η3-allyl supporting ligands, [(LNC)PdCl(L-κP)] and [(η3-C3H5)PdCl(L-κP)] (L = 1 and 2), respectively. These defined complexes as well as their surrogates generated in situ from the respective palladium(II) precursor and the phosphanylferrocene ligand were evaluated as catalysts for the coupling of boronic acids with acyl chlorides to give ketones in an aqueous biphasic system. The coupling reaction proceeded best with a simple catalyst formed from Pd(OAc)2and ligand 2, which (at 0.2 mol-% Pd loading) produced substituted benzophenones from benzoyl chlorides and benzeneboronic acids in very good yields. These yields could then be further improved by a proper choice of the reaction partners. Analogous reactions involving aliphatic substrates generally afforded lower yields.
- Charvátová, Hana,Císa?ová, Ivana,?těpni?ka, Petr
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p. 288 - 296
(2017/02/05)
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- Synthesis of a polar phosphinoferrocene amidosulfonate ligand and its application in pd-catalyzed cross-coupling reactions of aromatic boronic acids and acyl chlorides in an aqueous medium
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The reaction of [1′-(diphenylphosphino)ferrocenyl]methylamine (1), generated in situ from its hydrochloride and triethylamine, with 2-sulfobenzoic anhydride afforded an anionic phosphino-amide, which was isolated as a triethylammonium salt, Ph2PfcCH2NHCOC6H4SO3(HNEt3) (2; fc = ferrocene-1,1′-diyl). A similar reaction of 1 with phthalic anhydride only furnished the salt (Ph2PfcCH2NH3)[C6H4CO2H(CO2)]. When it was reacted with [PdCl2(MeCN)2] and [LNCPd(μ-Cl)]2 (LNC = 2-[(dimethylamino-κN)methyl]phenyl-κC1), compound 2 gave rise to the bis-phosphine complex [PdCl2(2-κP)2] and the bridge-cleavage product [LNCPdCl(2-κP)], respectively. An analogue of the latter complex containing 2′-amino-[1,1′-biphenyl]-2-yl-κ2N,C2 as the auxiliary chelating ligand, compound 8, was prepared in a similar manner from 2 and the respective Pd precursor. Finally, the reaction of 2 with [LNCPd(acac)] proceeded with the replacement of the acetylacetonate ligand (acac), affording a dipalladium complex featuring two phosphinosulfonate anions as the O,P-bridges, [LNCPd(μ(P,O)-Ph2PfcCH2NHCOC6H4SO3)]2, which was structurally characterized by single-crystal X-ray diffraction analysis. All of these Pd(II) complexes, especially compound 8, formed active catalysts for Pd-mediated cross-coupling of aromatic boronic acids with benzoyl chlorides to produce substituted benzophenones in toluene (benzene)-water biphasic mixtures. This particular coupling reaction was employed during the preparation of 4′-chloro-4-hydroxybenzophenone, which was in turn converted to fenofibrate, a generic drug widely used to reduce cholesterol levels in blood.
- ?koch, Karel,Císa?ová, Ivana,?těpni?ka, Petr
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p. 3378 - 3387
(2016/10/21)
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- Synthesis, structural characterization, and catalytic evaluation of phosphinoferrocene ligands bearing extended urea-amide substituents
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New phosphinoferrocene ligands bearing extended polar amidourea pendants with the general formula Ph2PfcCONHCH2CH 2NHCONR2 (1; R2 = H2 (b), H/Et (c), Me2 (d), H/Ph (e)) and their model bis-amide Ph 2PfcCONHCH2CH2NHCOCH3 (1a) were prepared in good yields by amidation of 1′-(diphenylphosphino)ferrocene-1- carboxylic acid (Hdpf) with the appropriate amines in the presence of peptide coupling reagents. These ferrocene-based phosphinoureas were further employed as ligands in palladium(II) complexes with η3-allyl and NC-chelating supporting ligands: viz., [PdCl(η3-C 3H5)(1-κP)] (5a-e) and [PdCl(LNC)(1- κP)] (6a-e; LNC = [2-(dimethylamino-κN)methyl]phenyl- κC1). Both the free ligands and their Pd(II) complexes were characterized by spectroscopic methods (multinuclear NMR, IR, and MS) and by elemental analysis. The molecular structures of 1b·CH3OH, 1c, 5b,c, 6a, and two additional model complexes, [PdCl(η3-C 3H5)(Hdpf-κP)] (5f) and [PdCl(η3- C3H5)(Ph2PfcCONH2-κP)] (5g), were determined by single-crystal X-ray diffraction analysis. All Pd(II) complexes were evaluated as catalysts in the cross-coupling of boronic acids and acyl halides to give ketones in a toluene/water biphasic mixture. Extensive reaction studies with compound 5e, which not only exerts good catalytic activity but is also readily accessible in a defined crystalline form, demonstrated efficient coupling reactivity for unsaturated substrates such as (substituted) benzeneboronic acids and benzoyl chlorides. The results also revealed that reaction difficulties encountered with less reactive substrates (e.g., insoluble aromatic boronic acids and all saturated aliphatic boronic acids) can be avoided by properly selecting the reaction partners, for example through transposition of substituents between reaction partners. Three representative benzophenones (4-fluoro-, 4-nitro-, and 4,4′-dinitrobenzophenone) were structurally characterized by single-crystal X-ray crystallography.
- Solarova, Hana,Cisarova, Ivana,Stepnicka, Petr
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p. 4131 - 4147
(2014/10/15)
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- NON-RESONANT TWO-PHOTON ABSORPTION RECORDING MATERIAL AND NON-RESONANT TWO-PHOTON ABSORPTION COMPOUND
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A non-resonant two-photon absorption recording material containing at least (a) a non-resonant two-photon absorption compound, and (b) a recording component in which at least either a refractive index or fluorescence intensity changes, wherein the non-resonant two-photon absorption compound (a) is a compound having a structure represented by formula (1) as described.
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Page/Page column 26
(2013/02/27)
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- Synthesis and biological activities of N,N-dimethyl-2-propen-1-amine derivatives
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The synthesis of several 3-(4'-bromo-4-yl)-3-(4-X-phenyl)-N,N-dimethyl-2-propen-1-amine derivatives is described.These compounds are potential trypanocide agents with relative low acute toxicities. the inhibition of growth of Escherichia coli by these drugs with different para-substitution on the phenyl moiety and their trypanocidal activities against epimastigote from Trypanosoma cruzi were investigated. - Keywords: Chagas's disease; trypanocide; Trypanosoma cruzi; aminopropene.
- Conti, R. De,Gimenez, S. M. N.,Haun, M.,Pilli, R. A.,Castro, S. L. De,Duran, N.
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p. 915 - 918
(2007/10/03)
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