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31.
32.
Antonio de León Josefina Pons Jordi García-Antón Xavier Solans Mercè Font-Bardia Josep Ros 《Polyhedron》2007
The reaction between 1,2-bis[3-(3,5-dimethyl-1-pyrazolyl)-2-thiapropyl]benzene (bddf) and [MCl2(CH3CN)2] (M = Pd(II), Pt(II)) in a 1:1 M/L ratio in CH2Cl2 or acetonitrile solution, respectively, gave the complexes trans-[MCl2(bddf)] (M = Pd(II) (1), Pt(II) (4)), and in a 2:1 M/L ratio led to [M2Cl4(bddf)] (M = Pd(II) (2), Pt(II) (5)). Treatment of 1 and 4 with AgBF4 and NaBPh4, respectively, gave the compounds [Pd(bddf)](BF4)2 (3) and [Pt(bddf)](BPh4)2 (6). When complexes 3 and 6 were heated under reflux in a solution of Et4NBr in CH2Cl2/CH3OH (1:1) for 24 h, analogous complexes to 1 and 4 with bromides instead of chlorides bonded to the metallic centre were obtained. These complexes were characterised by elemental analyses, conductivity measurements, infrared, 1H, 1H{195Pt}, 13C{1H}, 195Pt{1H} NMR, HSQC and NOESY spectroscopies. The X-ray crystal structure of the complex [Pd(bddf)](BF4)2 · H2O has been determined. The metal atom is tetracoordinated by the two azine nitrogen atoms of the pyrazole rings and two thioether groups. 相似文献
33.
Serrano P Casas J Zucco M Emeric G Egido-Gabás M Llebaria A Delgado A 《Journal of combinatorial chemistry》2007,9(1):43-52
Libraries of N-substituted aminocyclitol derivatives of the scyllo and racemic chiro series by means of parallel solution-phase methodology with the help of robotic technology are described. Chemical diversity has been introduced by reaction of selected scaffolds with a set of aldehydes, acyl chlorides, sulfonyl chlorides, chloroformates, and amines to afford the corresponding amines, amides, sulfonamides, carbamates and ureas, respectively. The optimized methodology has proven excellent, in terms of overall purities of the resulting libraries, for the production of amides. Sulfonamides and carbamates have been obtained in slightly lower purities, while amines afforded modest results. Selected library members have been evaluated as inhibitors of recombinant glucocerebrosidase with K(i) values ranging in the low micromolar scale for the most active members. 相似文献
34.
35.
Jordi Calveras Dr. Meritxell Egido‐Gabás Dr. Livia Gómez Josefina Casas Dr. Teodor Parella Dr. Jesús Joglar Dr. Jordi Bujons Dr. Pere Clapés Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(30):7310-7328
The chemoenzymatic synthesis of a collection of pyrrolidine‐type iminosugars generated by the aldol addition of dihydroxyacetone phosphate (DHAP) to C‐α‐substituted N‐Cbz‐2‐aminoaldehydes derivatives, catalyzed by DHAP aldolases is reported. L ‐Fuculose‐1‐phosphate aldolase (FucA) and L ‐rhamnulose‐1‐phosphate aldolase (RhuA) from E. coli were used as biocatalysts to generate configurational diversity on the iminosugars. Alkyl linear substitutions at C‐α were well tolerated by FucA catalyst (i.e., 40–70 % conversions to aldol adduct), whereas no product was observed with C‐α‐alkyl branched substitutions, except for dimethyl and benzyl substitutions (20 %). RhuA was the most versatile biocatalyst: C‐α‐alkyl linear groups gave the highest conversions to aldol adducts (60–99 %), while the C‐α‐alkyl branched ones gave moderate to good conversions (50–80 %), with the exception of dimethyl and benzyl substituents (20 %). FucA was the most stereoselective biocatalyst (90–100 % anti (3R,4R) adduct). RhuA was highly stereoselective with (S)‐N‐Cbz‐2‐aminoaldehydes (90–100 % syn (i.e., 3R,4S) adduct), whereas those with R configuration gave mixtures of anti/syn adducts. For iPr and iBu substituents, RhuA furnished the anti adduct (i.e., FucA stereochemistry) with high stereoselectivity. Molecular models of aldol products with iPr and iBu substituents and as complexes with the RhuA active site suggest that the anti adducts could be kinetically preferred, while the syn adducts would be the equilibrium products. The polyhydroxylated pyrrolidines generated were tested as inhibitors against seven glycosidases. Among them, good inhibitors of α‐L ‐fucosidase (IC50=1–20 μM ), moderate of α‐L ‐rhamnosidase (IC50=7–150 μM ), and weak of α‐D ‐mannosidase (IC50=80–400 μM ) were identified. The apparent inhibition constant values (Ki) were calculated for the most relevant inhibitors and computational docking studies were performed to understand both their binding capacity and the mode of interaction with the glycosidases. 相似文献
36.
Miguel Guerrero Josefina Pons Mercè Font-Bardia Teresa Calvet Josep Ros 《Journal of chemical crystallography》2011,41(5):721-726
Abstract
The crystal structure of the title compound C22H30N4O2·H2O (L), has been determined using X-ray diffraction at 293 K. The crystal of 1,2-bis[4-(3,5-dimethyl-1H-pyrazol-1-yl)-2-oxobutyl]benzene is in triclinic crystal system with space group P(−1) (Z = 2), lattice parameters a = 8.225(6) ?, b = 10.967(6) ?, c = 12.903(6) ?, V = 1119.1(11) ?3. Analyses of single crystals of L, crystallized from dichloromethane/diethyl ether (1:1), revealed that the molecules are arranged in couples, which adopt a pseudo chair conformation, by means of intermolecular O–H···N hydrogen bonding interactions. Moreover, the extended structure revealed a 1D chain caused by several C–H···N intermolecular interactions. 相似文献37.
Malgorzata Frik Dr. Josefina Jiménez Ismael Gracia Prof. Larry R. Falvello Sarya Abi‐Habib Karina Suriel Prof. Theodore R. Muth Prof. María Contel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(12):3659-3674
The reaction of new dinuclear gold(I) organometallic complexes containing mesityl ligands and bridging bidentate phosphanes [Au2(mes)2(μ‐LL)] (LL=dppe: 1,2‐bis(diphenylphosphano)ethane 1 a , and water‐soluble dppy: 1,2‐bis(di‐3‐pyridylphosphano)ethane 1 b ) with Ag+ and Cu+ lead to the formation of a family of heterometallic clusters with mesityl bridging ligands of the general formula [Au2M(μ‐mes)2(μ‐LL)][A] (M=Ag, A=ClO4?, LL=dppe 2 a , dppy 2 b ; M=Ag, A=SO3CF3?, LL=dppe 3 a , dppy 3 b ; M=Cu, A=PF6?, LL=dppe 4 a , dppy 4 b ). The new compounds were characterized by different spectroscopic techniques and mass spectrometry The crystal structures of [Au2(mes)2(μ‐dppy)] ( 1 b ) and [Au2Ag(μ‐mes)2(μ‐dppe)][SO3CF3] ( 3 a ) were determined by a single‐crystal X‐ray diffraction study. 3 a in solid state is not a cyclic trinuclear Au2Ag derivative but it gives an open polymeric structure instead, with the {Au2(μ‐dppe)} fragments “linked” by {Ag(μ‐mes)2} units. The very short distances of 2.7559(6) Å (Au? Ag) and 2.9229(8) Å (Au? Au) are indicative of gold–silver (metallophilic) and aurophilic interactions. A systematic study of their luminescence properties revealed that all compounds are brightly luminescent in solid state, at room temperature (RT) and at 77 K, or in frozen DMSO solutions with lifetimes in the microsecond range and probably due to the self‐aggregation of [Au2M(μ‐mes)2(μ‐LL)]+ units (M=Ag or Cu; LL=dppe or dppy) into an extended chain structure, through Au? Au and/or Au? M metallophilic interactions, as that observed for 3 a . In solid state the heterometallic Au2M complexes with dppe ( 2 a – 4 a ) show a shift of emission maxima (from ca. 430 to the range of 520‐540 nm) as compared to the parent dinuclear organometallic product 1 a while the complexes with dppy ( 2 b–4 b ) display a more moderate shift (505 for 1 b to a max of 563 nm for 4 b ). More importantly, compound [Au2Ag(μ‐mes)2(μ‐dppy)]ClO4 ( 2 b ) resulted luminescent in diluted DMSO solution at room temperature. Previously reported compound [Au2Cl2(μ‐LL)] (LL dppy 5 b ) was also studied for comparative purposes. The antimicrobial activity of 1–5 and Ag[A] (A=ClO4?, SO3CF3?) against Gram‐positive and Gram‐negative bacteria and yeast was evaluated. Most tested compounds displayed moderate to high antibacterial activity while heteronuclear Au2M derivatives with dppe ( 2 a – 4 a ) were the more active (minimum inhibitory concentration 10 to 1 μg mL?1). Compounds containing silver were ten times more active to Gram‐negative bacteria than the parent dinuclear compound 1 a or silver salts. Au2Ag compounds with dppy ( 2 b , 3 b ) were also potent against fungi. 相似文献
38.
Tuning the hemilabile behaviour of a thioether–pyrazole ligand on Pd(II) complexes with diphosphines
Antonio de León José Antonio Ayllón Josefina Pons 《Journal of organometallic chemistry》2012,696(26):4275-4280
The coordination mode of thioether–pyrazole ligand, 1,5-bis(3,5-dimethyl-1-pyrazolyl)-3-thiapentane (bdtp) and 1,8-bis-(3,5-dimethyl-1-pyrazolyl)-3,6-dithiaoctane (bddo) ligands, in Pd(II) complexes containing a diphosphine ligand is determined by subtle changes in size of the bridge between the two phosphorus atoms. The 1H NMR and 31P{1H} NMR at variable temperature in acetonitrile solution prove that the hemilabile character of the bdtp ligand depend on the diphosphine ligand. Thus, while in [Pd(bdtp)(dppe)](BF4)2 [1](BF4)2 the thioether group not participate in the Pd(II) coordination sphere, two isomers with different coordination (P2N2 vs P2NS) are in equilibrium in [Pd(bdtp)(dppp)](BF4)2 [2](BF4)2 acetonitrile solution. For complexes [Pd(bddo)(dppe)](BF4)2 [3](BF4)2 and [Pd(bddo)(dppp)](BF4)2 [4](BF4)2, only the coordination N,N is observed. 相似文献
39.
Josefina Alvarez Magali Folch-Gabayet Salvador Pérez-Esteva 《Journal of Fourier Analysis and Applications》2001,7(1):49-62
The purpose of this article is to study the Hilbert space W2\mathcal{ W}^2 consisting of all solutions of the Helmholtz equation Du+u=0\Delta u+u=0 in
\BbbR2\Bbb{R}^2 that are the image under the Fourier transform of L2L^2 densities in the unit circle. We characterize this space as a close subspace of the Hilbert space H2\mathcal{ H}^2 of all functions belonging to L2( | x | -3dx) L^2( | x | ^{-3}dx) jointly with their angular and radial derivatives, in the complement of the unit disk in
\BbbR2\Bbb{R}^2. We calculate the reproducing kernel of W2\mathcal{ W}^2 and study its reproducing properties in the corresponding spaces Hp\mathcal{H}^p, for $p>1$p>1. 相似文献
40.
Pablo Ríos Hugo Fouilloux Dr. Josefina Díez Dr. Pietro Vidossich Prof. Dr. Agustí Lledós Dr. Salvador Conejero 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(48):11346-11355
Platinum complexes [Pt(NHC′)(NHC)][BArF] (in which NHC′ denotes a cyclometalated N-heterocyclic carbene ligand, NHC) react with primary silanes RSiH3 to afford the cyclometalated platinum(II) silyl complexes [Pt(NHC-SiHR′)(NHC)][BArF] through a process that involves the formation of C−Si and Pt−Si bonds with concomitant extrusion of H2. Low-temperature NMR studies indicate that the process proceeds through initial formation of the σ-SiH complexes [Pt(NHC′)(NHC)(HSiH2R)][BArF], which are stable at temperatures below −10 °C. At higher temperatures, activation of one Si−H bond followed by a C−Si coupling reaction generates an agostic SiH platinum hydride derivative [Pt(H)(NHC′-SiH2R)(NHC)][BArF], which undergoes a second Si−H bond activation to afford the final products. Computational modeling of the reaction mechanism indicates that the stereochemistry of the silyl/hydride ligands after the first Si−H bond cleavage dictates the nature of the products, favoring the formation of a C−Si bond over a C−H bond, in contrast to previous results obtained for tertiary silanes. Furthermore, the process involves a trans-to-cis isomerization of the NHC ligand before the second Si−H bond cleavage. 相似文献