共查询到20条相似文献,搜索用时 31 毫秒
1.
Tushar Gosavi 《Inorganica chimica acta》2004,357(6):1781-1788
The platina-β-diketone [Pt2{(COMe)2H}2(μ-Cl)2] (1) was found to react with chelating N,N-ligands 2(R′NCR)C5H4N (R/R′=Ph/OH, H/Ph, Me/Ph) to form acyl(hydrido)platinum(IV) complexes [Pt(COMe)2Cl(H){2-(R′NCR)C5H4N}] (R/R′=Ph/OH 2a; H/Ph 2b; Me/Ph (2c)). Reactions of complex 1 with chelating S,S- and N,S-donors (RS-CH2-CH2-SR, 2-(RSCH2)C5H4N, R=Et, Ph, t-Bu) afforded acyl(chloro)platinum(II) complexes [Pt(COMe)Cl(RSCH2CH2SR)] (R=Et, 3a; Ph, 3b; t-Bu, 3c) and [Pt(COMe)Cl{2-(RSCH2)C5H4N}] (R=Et, 4a; Ph, 4b; t-Bu, 4c), respectively. All complexes were fully characterized by microanalysis, IR and NMR (1H, 13C) spectroscopy. Furthermore, molecular structures of complexes 3b and 4b were determined by single-crystal X-ray diffraction analyses revealing close to square-planar configuration. In complex 4b the acetyl ligand is trans to pyridine N atom (configuration index SP-4-2). The reactions are discussed in terms of consecutive oxidative addition and reductive elimination reactions. 相似文献
2.
Luigi Busetto Fabio Marchetti Stefano Zacchini Valerio Zanotti 《Inorganica chimica acta》2005,358(5):1469-1484
The new diiron alkynyl methoxy carbene complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO){C(OMe)CCR′}(Cp)2]+ (R = 2,6-Me2C6H3 (Xyl), R′ = Tol, 3a; R = Xyl, R′ = Ph, 3b; R = Xyl, R′=Bun, 3c; R = Xyl, R′=SiMe3, 3d; R = Me, R′ = Tol, 3e; R = Me, R′ = Ph, 3f) are obtained in two steps by addition of R′CCLi (R′ = Tol, Ph, Bun, SiMe3) to the carbonyl aminocarbyne complexes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO)2(Cp)2]+ (R = Xyl, 1a; Me, 1b), followed by methylation of the resulting alkynyl acyl compounds [Fe2{μ-CN(Me)(R)}(μ-CO)(CO){C(O)CCR′}(Cp)2] (R = Xyl, R′ = Tol, 2a; R = Xyl, R′ = Ph, 2b; R = Xyl, R′ = Bun, 2c; R = Xyl, R′ = SiMe3, 2d; R = Me, R′ = Tol, 2e; R = Me, R′ = Ph, 2f). Complexes 3 react with secondary amines (i.e., Me2NH, C5H10NH) to give the 4-amino-1-metalla-1,3-dienes [Fe2{μ-CN(Me)(R)}(μ-CO)(CO){C(OMe)CHC(R′)(NMe2)}(Cp)2]+ (R = Xyl, R′ = Tol, 4a; R = Xyl, R′ = Ph, 4b; R = Me, R′ = Ph, 4c) and [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){C(OMe)CHC(Tol)(NC5H10)}(Cp)2]+, 5. The addition occurs stereo-selectively affording only the E-configured products. Analogously, addition of primary amines R′NH2 (R′ = Ph, Et, Pri) affords the 4-(NH-amino)-1-metalla-1,3-diene complexes [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){C(OMe)CHC(R)(NHR′)}(Cp)2]+ (R = Ph, 6a; Et, 6b; Pri, 6c). In the case of 6a, only the E isomer is formed, whereas a mixture of the E and Z isomers is present in the case of 6b,c, with prevalence of the latter. Moreover, the two isomeric forms exist under dynamic equilibrium conditions, as shown by VT NMR studies. Complexes 6 are deprotonated by strong bases (e.g., NaH) resulting in the formation of the neutral vinyl imine complexes [Fe2{μ-CN(Me)(Xyl)}(μ-CO)(CO){C(OMe)CHC(NR)(Tol)}(Cp)2] (R = Ph, 7a; Et, 7b; Pri, 7c); the reaction can be reverted by addition of strong acids. X-ray crystal structures have been determined for 3a[CF3SO3] · Et2O, 4c[CF3SO3], 6a[BF4] · CH2Cl2, 6c[CF3SO3] · 0.5Et2O and 7a · CH2Cl2. 相似文献
3.
The reaction of alkyn-1-yl(vinyl)silanes R2Si(CCR1)CHCH2 [R = Me (1), Ph (2); R1 = tBu (a), Ph (b), SiMe3 (c)] with 9-borabicyclo[3.3.1]nonane in a 1:1 ratio affords the 1-silacyclopent-2-ene derivatives 4a-c (R = Me) and 5a-c (R = Ph) as a result of selective intermolecular 1,2-hydroboration of the vinyl group, followed by intramolecular 1,1-organoboration of the alkynyl substituent. The analogous reaction sequence converts the alkyn-1-yl(allyl)dimethylsilanes 3a,c into the 1-silacyclohex-2-ene derivatives 7a,c. All reactions were monitored by 29Si NMR spectroscopy and the structural assignment of the final products was based on multinuclear magnetic resonance data (1H, 11B, 13C and 29Si NMR). The molecular structure of 6a was determined by X-ray analysis. 相似文献
4.
Metal-sulfur complex fragments, to which small molecules like N2, N2H2, N2H4, NH3, or CO can bind, are desirable model compounds concerning enzymatic N2 fixation.This paper reports on the effects of the phosphane co-ligand on formation and reactivity of [Ru(L)(PR3)(`N2Me2S2')] [`N2Me2S2'2−=1,2-ethanediamine-N,N′-dimethyl-N,N′-bis(2-benzenethiolate)(2−)] complexes with nitrogenase relevant ligands, especially N2, N2H4, NH3, and CO.Treatment of [Ru(NCCH3)4Cl2] with Li2`N2Me2S2', excessive LiOMe, bulky PPh3 or PCy3, respectively, led to the formation of two series of [Ru(L)(PR3)(`N2Me2S2')] complexes [for R=Ph: 1b, 1c (L=NCCH3), 6b (L=N2H4), 7b (L=N2), 8b1-3 (L=CO), 9b (L=NH3); for R=Cy: 1a (L=NCCH3), 6a (L=N2H4), 7a (L=N2), 8a (L=CO), 9a (L=NH3)]. While the use of PPh3 (θ=145°) yielded cis,trans and cis,cis isomers of [Ru(NCCH3)(PPh3)(`N2Me2S2')] (1b, 1c), no isomer formation was observed with the bulkier phosphane PCy3 (θ=170°). Sterically less demanding phosphanes (θ=118-132°) afforded bisphosphane complexes [Ru(PR3)2(`N2Me2S2')] [2d (R=Me), 2e (R=Et), 2f (R=nPr), and 2g (R=nBu)], which were practically inert and could only be converted in two cases and under drastic reaction conditions into the CO complexes [Ru(CO)(PR3)(`N2Me2S2')] [4e (R=Et), 4f (R=nPr)]. The chelating bidentate phosphane dppe (bisdiphenylphosphanoethane) yielded exclusively the mononuclear complex [Ru(dppe)(`N2Me2S2')] (3). 相似文献
5.
Wolfdieter A. Schenk Birgit Vedder Christian Eichhorn 《Inorganica chimica acta》2004,357(6):1886-1896
Reaction of PPN[W(CO)3(R2PC2H4PR2)(SH)] (PPN=Ph3PNPPh3; R=Me, 1; R=Ph, 2) with aromatic aldehydes in the presence of trifluoroacetic acid gave tungsten complexes of thiobenzaldehydes mer-[W(CO)3(R2PC2H4PR2)(η2-SCHR′)] (R=Me, 3a-3f; R=Ph, 4a-4e) in high yields. Analogous complexes of aliphatic thioaldehydes mer-[W(CO)3(Me2PC2H4PMe2)(η2-SCHR′)] (3g-3l) could only be obtained from the highly electron-rich thiolate complex 1. The structure of 3i (R′=i-Bu) was determined by X-ray crystallography. In solution the complexes 3 and 4 are in equilibrium with small quantities of their isomers fac-[W(CO)3(R2PC2H4PR2)(η2-SCHR′)]. Reaction of complexes 3 with dimethylsulfate followed by salt metathesis with NH4PF6 gave the alkylation products mer-[W(CO)3(Me2PC2H4PMe2)(η2-MeSCHR′)]PF6 (5a-5l) as mixtures of E and Z isomers. The methylated thioformaldehyde complex mer-[W(CO)3(Me2PC2H4PMe2)(η2-MeSCH2)]PF6 (5m) was prepared similarly. Nucleophilic addition of hydride (from LiAlH4) to 5 initially gave thioether complexes mer-[W(CO)3(Me2PC2H4PMe2)(MeSCH2R′)] (mer-6) which rapidly isomerized to fac-[W(CO)3(Me2PC2H4PMe2)(MeSCH2R′)] (fac-6). 相似文献
6.
Hong-Xing Wang Hong-Fei Wu Feng-Ying Geng Xiao-Li Yang Wen-Qin Zhang 《Inorganica chimica acta》2006,359(12):4114-4120
Condensation of aminomethylferrocene (1) and substituted benzaldehydes resulted in aldimines 2a-c which followed by reduction with sodium borohydride to give 3a-c. N-methylation of 3a-c with HCHO/NaCNBH3/HOAc led to 4a-c. Treatment of 4a-c with sodium palladium tetrachloride in the presence of sodium acetate afforded cleanly cyclopalladated 5a-c in which configurations consisted of the RNRC, SNSC. The preferable activation of CFerrocenyl-H bond over CPhenyl-H bond was also observed. All compounds 2-5 were characterized by elemental analysis, IR and 1H NMR. In addition, the molecular structure of 5c was confirmed by single crystal X-ray diffraction. The possible mechanism for the formation of 5 was also discussed. 相似文献
7.
Reaction of ctc-OsBr2(RaaiR′)2 [RaaiR′=1-alkyl-2-(arylazo)imidazole, p-R-C6H4-NN-C3H2-NN-1-R′, where R=H (a), Me (b), Cl (c) and R′=Me (2), Et (3) and CH2Ph (4)] with 2,2′-bipyridine (bpy) in presence of AgNO3 in EtOH followed by the addition of NH4PF6 afforded a mixed ligand complex [Os(bpy)(RaaiR′)2](PF6)2. The structure of the complex, in one case [Os(bpy)(MeaaiMe)2](PF6)2 · 4H2O, has been confirmed by X-ray crystallography. The complexes are diamagnetic (low spin d6, s=0) and they show intense MLCT transition in the visible region (480-525 nm) and a weak transition at longer wavelength (>850 nm) in CH3CN solution. Cyclic voltammetry of the complexes show two metal oxidation, Os(II)/Os(III) at 0.72-0.76 V and Os(III)/Os(IV) at 1.34-1.42 V and three successive ligand reductions. 相似文献
8.
Normen Szesni 《Inorganica chimica acta》2005,358(5):1645-1656
The aminoallenylidene(pentacarbonyl)chromium complexes [(CO)5CrCCC(NR1R2)Ph] (1a-c) react with dimethylamine by addition of the amine to the C1C2 bond of the allenylidene ligand to give alkenyl(amino)carbene complexes [(CO)5CrC(NMe2)CHC(NR1R2)Ph] (2a-c) (R1 = Me: R2 = Me (a), Ph (b); R1 = Et: R2 = Ph (c)). In contrast, addition of a large excess (usually 20 equivalents) of ammonia or primary amines, H2NR, to solutions of [(CO)5CrCCC(NMe2)Ph] (1a) affords the aminoallenylidene complexes [(CO)5CrCCC(NHR)Ph] (1d-w) in which the dimethylamino group is replaced by NH2 or NHR, respectively. In addition to simple amines such as methylamine, butylamine, and aniline, amines carrying a functional group (allylamine, propargylamine) and amino acid esters as well as amino terpenes and amino sugars can be used to displace the NMe2 substituent. Usually the Z isomer (with respect to the partial C3-N double bond) is formed exclusively. Products derived from addition of H2NR to the C1C2 bond of 1a are not observed. The amino group in 1d-w is rapidly deprotonated by excess of amine to form iminium alkynyl chromates [1d-w]−, thus protecting 1d-w from addition of free amine to either C3 or across the C1C2 bond. The iminium alkynyl chromates are readily reprotonated by acids or by chromatography on wet SiO2 to reform 1d-w. 相似文献
9.
Quirante J Ruiz D Gonzalez A López C Cascante M Cortés R Messeguer R Calvis C Baldomà L Pascual A Guérardel Y Pradines B Font-Bardía M Calvet T Biot C 《Journal of inorganic biochemistry》2011,105(12):1720-1728
The study of the reactivity of three 1-(2-dimethylaminoethyl)-1H-pyrazole derivatives of general formula [1-(CH2)2NMe2}-3,5-R2-pzol] {where pzol represents pyrazole and RH (1a), Me (1b) or Ph (1c)} with [MCl2(DMSO)2] (MPt or Pd) under different experimental conditions allowed us to isolate and characterize cis-[M{κ2-N,N′-{[1-(CH2)2NMe2}-3,5-R2-pzol])}Cl2] {MMPtPt (2a-2c) or Pd (3a-3c)} and two cyclometallated complexes [M{κ3-C,N,N′-{[1-(CH2)2NMe2}-3-(C5H4)-5-Ph-pzol])}Cl] {MPt(II) (4c) or Pd(II) (5c)}. Compounds 4c and 5c arise from the orthometallation of the 3-phenyl ring of ligand 1c. Complex 2a has been further characterized by X-ray crystallography. Ligands and complexes were evaluated for their in vitro antimalarial against Plasmodium falciparum and cytotoxic activities against lung (A549) and breast (MDA MB231 and MCF7) cancer cellular lines. Complexes 2a-2c and 5c exhibited only moderate antimalarial activities against two P. falciparum strains (3D7 and W2). Interestingly, cytotoxicity assays revealed that the platinacycle 4c exhibits a higher toxicity than cisplatin in the three human cell lines and that the complex 2a presents a remarkable cytotoxicity and selectivity in lung (IC50 = 3 μM) versus breast cancer cell lines (IC50 > 20 μM). Thus, complexes 2c and 4c appear to be promising leads, creating a novel family of anticancer agents. Electrophoretic DNA migration studies in presence of the synthesized compounds have been performed, in order to get further insights into their mechanism of action. 相似文献
10.
4-aryl-2-amino-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)-pyridin-3-carbonitrile (1), 4-aryl-2-oxo-6-(4-hydroxy-2-oxo-2H-chromen-3-yl)-pyridin-3-carbonitriles (2a-2c), 3-(6-aryl-1,2,5,6- tetrahydro-2-thioxopyrimidin-4-yl)-4-hydroxy-2H-chromen-2-one (3a, 3b) and pyrazol-3-yl-4-hydroxycoumarin derivatives (4a-4c, 5, 6a, 6b, 7a, 7b, and 8a-8c) were prepared in order to measure their % change dopamine release in comparison to amphetamine as reference, using PC-12 cells in different concentrations. In addition, the molecular modeling study of the compounds into 3BHH receptor was also demonstrated. The calculated inhibition constant (ki) implemented in the AutoDock program revealed identical correlation with the experimental results to that obtained binding free energy (ΔGb) as both parameters revealed reasonable correlation coefficients (R2) being 0.51 involving 10 compounds; (1, 2b, 2c, 3a, 3b, 4a, 4b, 6a, and 8c). 相似文献
11.
Iminophosphinite pincer palladium complexes were synthesized and evaluated as potential catalysts in the Suzuki coupling reactions of phenylboronic acid and various aryl halides. The iminophosphinite ligands were synthesized through condensation reactions between 2-bromo-3-hydroxybenzaldehyde and 2,4,6-trimethylaniline and 2,6-diisopropylaniline, followed by phosphorylation with chlorodiphenylphosphine and chlorodicyclohexylphosphine. Oxidative addition of the pincer ligands to Pd2(dba)3 afforded palladium iminophosphinite complexes [(2-(CHNR)-6-(OPR′2)C6H3)PdBr] (R = 2,6-iPr2C6H3, R′ = Ph (2a) or Cy (2b); R = 2,4,6-Me3C6H2, R′ = Ph (2c) or Cy (2d)). Reaction of 2b and silver trifluoroacetate gave the corresponding iminophosphinite palladium trifluoroacetate (3). The solid state structures of 2a, 2d, and 3 were determined by X-ray single crystal diffraction studies. 相似文献
12.
Mercury(II) acetate reacts with the 1-alkyl-2-(arylazo)imidazoles [RaaiR′ where R = H (a), Me (b); R′ = Me (1/3/5), Et (2/4/6)] and sodium azide in methanol solution to afford azido bridged polymeric complexes [Hg(RaaiR′)(N3)2]n (3/4). On setting up similar reaction condition, the reaction of Hg(OAc)2 with RaaiR′ and NH4SCN has yielded, instead of polymer, an ion-pair [Hg(RaaiR′)4][Hg(SCN)4] (5/6). The complexes are characterised by elemental analysis, IR, UV-Vis, 1H NMR spectral data and single-crystal X-ray structures of [Hg(HaaiEt)(μ-1,1-N3)2]n (4a) and [Hg(HaaiEt)4][Hg(SCN)4] (6a). The complex 4a is a coordination polymer with end-on (μ-1,1) azido bridge and 6a has tetrahedral structure. 相似文献
13.
Tanabe G Otani T Cong W Minematsu T Ninomiya K Yoshikawa M Muraoka O 《Bioorganic & medicinal chemistry letters》2011,21(10):3159-3162
Four analogs with 3′-O-alkyl groups (9a: CH3, 9b: C2H5, 9c: C13H27 or 9d: CH2Ph) instead of the 3′-O-sulfate anion in salacinol (1), a naturally occurring potent α-glucosidase inhibitor, were synthesized by the coupling reaction of 1,4-dideoxy-1,4-epithio-d-arabinitols (18a and 18b) with appropriate epoxides (10a-10d). These analogs showed equal or considerably higher inhibitory activity against rat small intestinal α-glucosidases than the original sulfate (1), and one of them (9d) was found more potent than currently used α-glucosidase inhibitors as antidiabetics. Thus, introduction of a hydrophobic moiety at the C3′ position of this new class of inhibitor was found beneficial for onset of stronger inhibition against these enzymes. 相似文献
14.
Ron SiebenlistHans-Werner Frühauf Huub KooijmanNora Veldman Anthony L SpekKees Goubitz Jan Fraanje 《Inorganica chimica acta》2002,327(1):66-89
Reaction of Fe2(CO)9 at room temperature in THF with the di-thiooxamides (L), SC{N(R,R′)}C{(R,R′)N}S [R=Me, R′-R′=(CH2)2 (a); R=H, R′=iPr (b); R=H, R′=iPr (c), R=H, R′=benzyl (d); R=H, R′=H (e)], results for ligands a-d initially in the formation of the mononuclear σ-S, σ-S′ chelate complexes Fe(CO)3(L) (7a-d), which could be isolated in case of 7a and 7d. Under the reaction conditions, complexes 7a-d react further with [Fe(CO)4] fragments to give three types of Fe2(CO)6(L) complexes (8a-d) in high yields, depending on the di-thiooxamide ligand used together with traces of the known complex S2Fe3(CO)9 (14). The molecular structures of these complexes have been established by the single crystal X-ray diffraction determinations of 8a, 8b and 8d. In the reaction with ligand e the corresponding complex 7e was not detected and the well-known complexes 14 and S2Fe3(CO)9 (15) were isolated in low yield. In situ prepared 7a reacts in a slow reaction with 1 equiv. of dimethyl acetylene dicarboxylate in a 1,3-dipolar cycloaddition reaction to give the stable initial ferra [2.2.1] bicyclic complex 10a in 60% yield. In complex 10a an additional Fe(CO)4 fragment is coordinated to the sulfido sulfur atom of the cycloadded FeSC fragment. When a toluene solution of 10a is heated to 50 °C it loses two terminal CO ligands to give the binuclear FeFe bonded complex 11a in almost quantitative yield. The molecular structures of 10a and 11a have been confirmed by single crystal X-ray diffraction. Reaction of 7d at room temperature with 2 equiv. of dimethyl acetylene dicarboxylate results in the mononuclear complex 12d in 5% yield. The molecular structure of 12b has been established by single crystal X-ray diffraction and comprises a tetra dentate ligand with two ferra-sulpha cyclobutene, and a ferra-disulpha cyclopentene moiety. When the reaction is performed at 60 °C a low yield of 2,3,4,5-thiophene tetramethyl tertracarboxylate is obtained besides complex 12d. 相似文献
15.
Complexes of type [M(tftb)2Ln] [M=Sr; n=1, L=tetraglyme (4), 2,3-benzo-10-aza-1,4,7,13-tetraoxacyclopentadeca-2-ene (batcp) (5), n=2, L=2,2′-bipyridine-N,N′ (bipy) (6); M=Ba; n=1, L=tetraglyme (7), 2,3-benzo-10-aza-1,4,7,13-tetraoxacyclopentadeca-2-ene (batcp) (8); n=2, L=2,2′-bipyridine-N,N′ (bipy) (9)] were prepared by in situ reactions of 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (Htftb) (1) with M(OH)2 [M=Sr (2a); Ba (2b)] in the presence of the ancillary ligands L (3a: L=tetraglyme; 3b: L=2,3-benzo-10-aza-1,4,7,13-tetraoxacyclopentadeca-2-ene (batcp); 3c: L=2,2′-bipyridine-N,N′ (bipy)) in aqueous ethanol. The compounds were obtained in high yields and characterized by elemental analysis, 1H NMR, mass spectrometry and IR analysis. Molecular structure of the [Sr(tftb)2(batcp)] (5) has been determined by X-ray single crystal analysis. 相似文献
16.
Aryloxide rhodium(I) complexes Rh(OAr)(PPh3)3 (1a: Ar=C6Cl5, 1b: Ar=C6F5, 1c: Ar=C6H4-NO2-4) react with CO in toluene solutions to produce Vaska-type complexes trans-Rh(OAr)(CO)(PPh3)2 (2a: Ar=C6Cl5, 2b: Ar=C6F5, 2c: Ar=C6H4-NO2-4). Carbonylation of a similar complex with PMe3 ligands, Rh(OC6H4-NO2-4)(PMe3)3 (3c), also forms trans-Rh(OC6H4-NO2-4)(CO)(PMe3)2 (4c). Molecular structures of the complexes are determined by X-ray crystallography and NMR spectroscopy. Complex 1a reacts with CO in the absence of solvent to produce a mixture of 2a and complex A, the latter of which shows the IR and 13C{1H} signals due to the carbonyl ligand at different positions from those of 2a. Addition of Et2O to the above mixture turns it into analytically pure 2a. Carbonylation of 1b and 1c under the solvent-free conditions produces complexes B and C as the respective products of the solid-gas reaction. Recrystallization of B and C turns them into 2b and 2c, respectively. Complex 3c also reacts with CO in the solid state to form a mixture of 4c and complex D, although the latter complex is converted slowly into 4c even in the solid state. 相似文献
17.
Tina Osswald 《Inorganica chimica acta》2010,363(3):474-480
The synthesis, characterization, and application in asymmetric catalytic cyclopropanation of Rh(III) and Ir(III) complexes containing (Sa,RC,RC)-O,O′-[1,1′-binaphthyl-2,2′-diyl]-N,N′-bis[1-phenyl-ethyl]phosphoramidite (1) are reported. The X-ray structures of the half-sandwich complexes [MCl2(C5Me5)(1,κP)] (M = Rh, 2a; M = Ir, 2b) show that the metal-phosphoramidite bond is significantly shorter in the Ir(III) analog. Chloride abstraction from 2a (with CF3SO3SiMe3 or with CF3SO3Me) and from 2b (with AgSbF6) gives the cationic species [MCl(C5Me5)(1,2-η-1,κP)]+ (M = Rh, 3a; M = Ir, 3b), which display a secondary interaction between the metal and a dangling phenethyl group (NCH(CH3)Ph) of the phosphoramidite ligand, as indicated by NMR spectroscopic studies. Complexes 3a and 3b slowly decompose in solution. In the case of 3b, the binuclear species [Ir2Cl3(C5Me5)2]+ is slowly formed, as indicated by an X-ray study. Preliminary catalytic tests showed that 3a cyclopropanates styrene with moderate yield (35%) and diastereoselectivity (70:30 trans:cis ratio) and with 32% ee (for the trans isomer). 相似文献
18.
Dirk Weber Sven H. Hausner Axel Eisengräber-Pabst Jeanette A. Krause-Bauer 《Inorganica chimica acta》2004,357(1):125-134
Pentacoordinated tin is known since the late 1950s but little is known about the ability of lead to form similar structures. Originally we investigated the reaction between a number of tetraorganylphosphonium chlorides [PR4]+Cl− (R=Me, Bun, and Ph) and several diorganyltin dichlorides SnR′2Cl2 (R′=Me, Et, Prn, Bun, Ph, o-, m-, p-Tol) between 100 and 240 °C. Novel pentacoordinated tin complexes, tetraorganylphosphonium diorganyltrichlorostannates [PR4][SnR′2Cl3] (1-19), were formed in good to excellent yields. In a second step, this synthetic approach was extended to include the reaction of diphenyllead dichloride Ph2PbCl2 with [PR4]+Cl− (R=Bun, Ph). Surprisingly, a two chloride transfer was observed to form the hexacoordinated lead species [PBun4]2[PbPh2Cl4] (20). Under similar conditions, the pentacoordinated [PPh4][PbPh3Cl2] (21) was obtained by a phenyl transfer. Complexes 20 and 21 were characterised by NMR (1H, 13C, 31P, and 207Pb), IR, MS, and X-ray crystallography. The anion of 20 assumes a lightly distorted octahedral geometry with the phenyl substituents in trans-positions. In the anion of 21 the phenyl substituents occupy the equatorial positions of a lightly distorted trigonal bipyramid. A thorough spectroscopical investigation of the tin complexes 1-19, including X-ray structural studies, which were possible for complexes with R′=aryl, revealed that these complexes are monomeric with a distorted trigonal bipyramidal [SnR′2Cl3]− anion. Both aryl groups occupy equatorial positions. 相似文献
19.
Thiocarbonate ruthenium complexes of the form CpRu(L)(L′)SCO2R (L = L′ = PPh3 (1), 1/2 dppe (2), L = PPh3, L′ = CO (3); R = Et (a), Bun (b), C6H5 (c), 4-C6H4NO2 (d)) have been synthesized by the reaction of the corresponding sulfhydryl complexes, CpRu(L)(L′)SH, with chloroformates, ROCOCl, at low temperature. The bis(triphenylphosphine) complexes 1 can be converted to 3 under CO atmosphere. The crystal structures of CpRu(PPh3)2SCO2Bun (1b), CpRu(dppe)SCO2Bun (2b), and CpRu(PPh3)(CO)SCO2Bun (3b) are reported. 相似文献
20.
The new diruthenium complexes trans-[(NH3)5Ru(L-L)Ru(NH3)4(bpy-Me)](PF6)5 (L-L are the bridging ligands pyrazine, 2a; 4,4′dipyridyl, 2b; and trans-1,2-bis(4-pyridyl)-ethylene, 2c; bpy-Me is N-methyl-pyridyl-pyridinium) are generated from the new complexes (L-L)Ru(NH3)4(bpy-Me)](PF6)3 (1a-c) and [(NH3)5Ru(H2O)](PF6)2. Cyclic voltammetry on the new compounds in acetonitrile electrolyte reveals two quasi-reversible oxidation steps corresponding to the two RuII/III couples in 2b and 2c and a single oxidations for 1a-c. In addition, two reduction waves are observed for the bpy-Me ligands of 1a-c and 2a-c. All of the new compounds exhibit multiple metal-to-ligand charge transfer (MLCT) bands in the visible region of the spectrum. For compounds 1a-c the most intense absorption in the visible region decreases in energy as the length of the aromatic bridging ligands increases. By contrast the strongest absorption band of 2a is lower in energy than the most intense bands of both 2b and 2c. Single crystal X-ray analysis of 2a reveals that the bridging pyridine is coplanar with the pyridyl ring of the bpy-Me ligand that is attached to the Ru center. DFT calculations on 2a indicate that the HOMO is localized predominately on the {(NH3)5Ru-pyz-Ru(NH3)4} portion of the complex and the LUMO has slightly more contribution from the bpy-Me ligand. 相似文献