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A range of alkyl- or aryl-substituted iron succinoyl complexes, incorporating the iron chiral auxiliary [(η5-C5H5)Fe(CO)(PPh3)], were prepared in high regio- and diastereoselectivities by employing four successful strategies: (i) the alkylation of chiral enolate equivalents with tert-butyl bromoacetate; (ii) the mutual kinetic resolution of tert-butyl α-bromoacetate with a chiral acetate enolate equivalent; (iii) the alkylation of chiral succinoyl enolate equivalents; (iv) the conjugate addition of organolithium reagents or lithium amide reagents to chiral fumaroyl derivatives. Oxidative cleavage of the iron chiral auxiliary was shown to occur without compromising the stereochemical integrity of the succinoyl fragments.  相似文献   

4.
Conjugate addition of achiral lithium dimethylamide to the chiral iron cinnamoyl complexes (S,E)- and (S,Z)-[(η5-C5H5)Fe(CO)(PPh3)(COCHCHPh)] proceeds with high diastereoselectivity, with this protocol being used to establish unambiguously the absolute configuration of Winterstein’s acid (3-N,N-dimethylamino-3-phenylpropanoic acid) as (R). The highly diastereoselective conjugate addition of lithium N-benzyl-N-trimethylsilylamide to a range of α,β-unsaturated iron acyl complexes, followed by in-situ elaboration of the derived enolate by either alkylation or aldol reactions is also demonstrated, facilitating the stereoselective synthesis of both cis- and trans-β-lactams. This methodology has been used to effect the formal asymmetric syntheses of (±)-olivanic acid and (±)-thienamycin. Addition of chiral lithium amides derived from primary and secondary amines to the iron crotonyl complex [(η5-C5H5)Fe(CO)(PPh3)(COCHCHMe)] indicates that lithium N-α-methylbenzylamide shows low levels of enantiorecognition, while lithium N-3,4-dimethoxybenzyl-N-α-methylbenzylamide and lithium N-benzyl-N-α-methylbenzylamide show high levels of enantiodiscrimination. The high level of observed enantiorecognition was used to facilitate a kinetic resolution of (RS)-[(η5-C5H5)Fe(CO)(PPh3)(COCHCHMe)] with homochiral lithium (R)-N-3,4-dimethoxybenzyl-N-α-methylbenzylamide. Further mechanistic studies show that conjugate additions of (RS)-lithium N-benzyl-N-α-methylbenzylamide to either the (RS)- or homochiral iron crotonyl complex show 2:1 stoicheiometry, while homochiral lithium N-benzyl-N-α-methylbenzylamide shows 1:1 stoicheiometry.  相似文献   

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The reaction of [(η5-C9H7)Ru(η2-dppe)Cl] (1) with monodentate nitriles, (L) in the presence of NH4PF6 afforded the complexes [(η5-C9H7)Ru(η2-dppe)(L)]PF6, with L?=?CH3CN (2a), CH3CH=CHCN (2b), NCC6H4CN (2c), C6H5CH2CN (2d), respectively. However, reaction of 1 with NH4PF6 in methanol yielded an amine complex of the type [(η5-C9H7) Ru(η2-dppe)(NH3)]PF6 (3a). The complexes were fully characterized by spectroscopy and analytical data. The molecular structures of the complexes [(η5-C9H7)Ru(η2-dppe) (CH3CN)]PF6 (2a) and [(η5-C9H7)Ru(η2-dppe)(NH3)]PF6 (3a) have been determined by single crystal X-ray analyses.  相似文献   

7.
The reaction of the complex [{(η6-C6Me6)Ru(μ-Cl)Cl}2] 1 with sodium azide ligand gave two new dimers of the composition [{(η6-C6Me6)Ru(μ-N3)(N3)}2] 2 and [{(η6-C6Me6)Ru(μ-N3)Cl}2] 3, depending upon the reaction conditions. Complex 3 with excess of sodium azide in ethanol yielded complex 2. These complexes undergo substitution reactions with monodentate ligands to yield monomeric complexes of the type [(η6-C6Me6)Ru(X)(N3)(L)] {X = N3, Cl, L = PPh3 (4a, 9a); PMe2Ph (4b, 9b); AsPh3 (4c, 9c); X = N3, L = pyrazole (Hpz) (5a); 3-methylpyrazole (3-Hmpz) (5b) and 3,5-dimethyl-pyrazole (3,5-Hdmpz) (5c)}. Complexes 2 and 3 also react with bidentate ligands to give bridging complexes of the type [{(η6-C6Me6)Ru(N3)(X)]2(μ-L)} {X = N3, Cl, L = 1,2-bis(diphenylphosphino)methane (dppm) (6, 10); 1,2-bis(diphenylphosphino)ethane (dppe) (7, 11); 1,2-bis(diphenylphosphino)propane (dppp) (8, 12); X = Cl, L = 4,4-bipyridine (4,4′-bipy) (13)}. These complexes were characterized by FT-IR and FT-NMR spectroscopy as well as by analytical data.The molecular structures of the representative complexes [{(η6-C6Me6)Ru(μ-N3)(N3)}2] 2, [{(η6-C6Me6)Ru(μ-N3)Cl}2] 3,[(η6-C6Me6)Ru(N3)2(PPh3)] 4a and [{(η6-C6Me6)Ru(N3)2}2 (μ-dppm)] 6 were established by single crystal X-ray diffraction studies.  相似文献   

8.
With copper(I) iodide as catalyst, σ-alkynyls, compounds (η5-C5H5)Cr(NO)2(CC-C6H5) (5), [(η5-C5H4)-COOCH3]Cr(NO)2(CC-C6H5) (10), and [(η5-C5H4)-COOCH3]W(CO)3(CC-C6H5) (13), were prepared from their corresponding metal chloride 1, 6 and 12. Structures of compound 3, 5 and 12 have been solved by X-ray diffraction studies. In the case of 5, there is an internal mirror plane passing through the phenylethynyl ligand and bisecting the Cp ring. The phenyl group is oriented perpendicularly to the Cp with an eclipsed conformation. The twist angle is 0° and 118.4° for -CC-Ph and two NO ligands, respectively. The orientation is rationalized in terms of orbital overlap between ψ3 of Cp, dπ of Cr atom, and π of alkynyl ligand, and complemented by molecular orbital calculation. The opposite correlation was observed on the chemical shift assignments of C(2)-C(5) on Cp ring in compounds 6 and 12, using HetCOR NMR spectroscopy. The electron density distribution in the cyclopentadienyl ring is discussed on the basis of 13C NMR data and compared with the calculations via density functional B3LYP correlation-exchange method.  相似文献   

9.
在无水乙醇中,用吡咯烷二硫代氨基甲酸铵(APDTC)和1,10-邻菲咯啉(o-phen·H2O)与TmCl3·3.65H2O作用,合成了未见文献报道的三元固态配合物,确定它的组成为Tm[(C5/sub>H8NS2)3(C12H8N2)]。 用RD496-Ⅲ微量热计测定了298.15 K下水合氯化铥及两个配体在无水乙醇中的溶解焓,两个配体醇溶液的混合焓及不同温度下标题化合物液相生成反应的焓变。在实验和计算基础上,得到了液相生成反应的热力学参数(活化焓、活化熵和活化自由能),速率常数和动力学参数(表现活化能、频率因子和反应级数)。通过合理的热化学循环,求得了298.15 K时标题化合物的固相生成反应焓变;推导了用该热量计测定固态物质比热容的计算式,并测定了题目配合物298.15 K的比热容。用RBC-Ⅱ精密转动弹热量计测定了题目配合物的恒容燃烧热, 计算了它们的标准摩尔燃烧焓和标准摩尔生成焓。  相似文献   

10.
Treatment of the molybdenum tetracarbonyl complexes of [Mo(CO)4L2] (L2=pyridyl amine Schiff base ligands) with allyl chloride in refluxing THF afforded η3-allyl complexes [MoCl(CO)2L23-allyl)] (1-9). These complexes have been characterised by various techniques including 1H-NMR, IR and FABMS spectroscopies and the single crystal X-ray structure determinations of the complexes [MoCl(CO)2{N(C6H4-2-OMe)C(Me)C5H4N}(η3-C3H5)] (3) and [MoCl(CO)2{N(Me)C(Ph)C5H4N}(η3-C3H5)] (4).  相似文献   

11.
The nickel-molybdenum complex [(η5-C5Me5)NiMo(CO)35-C5H4Me)] can be considered to contain a partially dative nickel-molybdenum double bond. This complex reacts with the bulky terminal alkyne HCCCPh2(OMe) (DPMP) to afford the alkyne-carbonyl coupled metallacyclic product (3c, R = CPh2(OMe), Ni-Mo) regioselectively and exclusively. No traces of a nickel-molybdenum μ-alkyne complex, analogous to similar complexes isolated with less bulky alkynes, were observed. The structure of complex 3c was established via a single crystal X-ray diffraction study. It exhibits the same connectivity as that observed with a related complex formed with the smaller but-2-yne, but some significant differences are observed between the two structures. Reactions of the nickel-molybdenum and -tungsten species [(η5-C5Me5)NiM(CO)35-C5H5)] (M = Mo, W) with DPMP proceeded analogously and afforded similar products.  相似文献   

12.
Treatment of [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(COD) (1) with phosphites, phosphines, amines or N-heterocyclic carbene in THF afforded the COD displacement complexes [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[P(OEt)3]2 (2), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[PPh2(OEt)]2 (3), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[NH2CH2CH2Pri]2 (4), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NH2Prn)2 (5), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru (η2-NH2CH2CH2NH2) (6), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[η2-NH(CH3)CH2CH2NH(CH3)] (7) or [η5:σ-Me2C(C5H4)(C2B10H10)]Ru[NHC]2 (8, NHC = 1,3,4,5-tetramethylimidazol-2-yilidene), respectively. Ruthenium-amine complexes were much more labile than 1. Upon exposure to moisture, 5 was converted into [{η5:σ-Me2C(C5H4)(C2B10H10)}Ru(μ-H2O)]2 (9). Reactions of 5 with PR3 (R = PPh3, Cy), TMEDA (TMEDA = N,N,N′,N′-tetramethylethylenediamine) and CH3CN afforded the corresponding amine replacement products[η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NH2Prn)(PPh3) (10), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NH2Prn)(PCy3) (11), [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(TMEDA) (12) and [η5:σ-Me2C(C5H4)(C2B10H10)]Ru(NCCH3)2 (13). These results indicated that the steric factor dominated these substitution reactions. The electrochemical studies showed that the electron richness of the Ru atom decreased in the order L2Ru(NHC)2 > L2Ru(amine)2 > L2Ru(NCMe)2 > L2Ru(P)2. All of these complexes were fully characterized by various spectroscopic techniques and elemental analyses. The molecular structures of 2, 3, 5-10, 12 and 13 were further confirmed by single-crystal X-ray analyses.  相似文献   

13.
The tetraethyl- and tetramethyl-cyclobutadiene complexes [(η4-C4R4)Co(η5-C5H4CHO)] R = Et, 5, R = Me, 7, and [(η4-C4R4)Co(η5-C5H4CO2Me)] R = Et, 6, R = Me, 8, are conveniently prepared by photolysis of the corresponding isocobaltocenium cations [(η4-C4R4)Co(η6-C6H5Me)]+ in acetonitrile, and subsequent treatment with Na[C5H4CHO] or Na[C5H4CO2Me]. The aldehydes 5 and 7 undergo Wittig and Knoevenagel reactions with [FcCH2PPh3]I and CH2(CN)2, to form [(η4-C4R4)Co(η5-C5H4CH=CHFc)] and [(η4-C4R4)Co(η5-C5H4CH=C(CN)2], 11 and 15, respectively. The Horner-Wittig reaction of [(η4-C4R4)Co(η5-C5H4CH2P(O)(OEt)2] with [(η4-C4Ph4)Co(η5-C5H4CHO)] yields [(η4-C4R4)Co(η55-C5H4CHCH-C5H4)Co(η4-C4Ph4)], 12 and 13. [(η4-C4Me4)Co(η5-C5H4CHO)] also reacts with t-BuLi and FcLi to furnish the corresponding secondary alcohols, 16 and 17, respectively. Surprisingly, the attempted direct synthesis of 5 by reaction of Na[C5H5] and ethyl formate with [(η4-C4Et4)Co(CO)2I], 1, instead yielded [(η5-C5H5)Co(η4-3,4,5,6-tetraethyl-α-pyrone)], 18, and a mechanistic proposal is advanced. The X-ray crystal structures of 1, 7, 8, 11(Z), 15 and 18, and also the isocobaltocenium salts [(η4-C4Et4)Co(η6-C6H5Me)][PF6], 2, and [(η4-C4Et4)Co(η6-1,3,5-C6H3Me3)][PF6], 4, are reported.  相似文献   

14.
The reaction of complex [(η6-C6Me6)Ru(μ-Cl)Cl]2 (1) with sodium azide yielded complexes of the composition [(η6-C6Me6)Ru(μ-N3)(N3)]2 (2) and [(η6-C6Me6)Ru(μ-N3)(Cl)]2 (3), depending upon the reaction conditions. Complex 3 with excess of sodium azide in ethanol yielded complex 2. Complexes 2 and 3 undergo substitution reactions with monodentate ligands such as PPh3, PMe2Ph and AsPh3 to yield monomeric complexes. The structure of complex 2 was determined by X-ray crystallography. All these complexes were characterized by micro analytical data and by FT-IR and FT-NMR spectroscopy. Complex 2 crystallizes in the monoclinic space group P21/n with a = 8.5370(11) Å, b = 16.192(2) Å, c = 10.4535(13) Å and β = 110.877(2)°.  相似文献   

15.
Cobaltacarboranes (η1, η3-cyclooctenediyl)Co(Carb) (Carb = η-9-SMe2-7,8-C2B9H10, η-1-tBuHN-1,7,9-C3B8H10) were synthesized by the reaction of the carborane anions [Carb] with the acetonitrile complex [(η1, η3-cyclooctenediyl)Co(MeCN)3]+ generated in situ upon the dissolution of [(η1, η3-cyclooctenediyl)Co(η-1,4-C6H4Me2)]+ in MeCN. The structures of (η13-cyclooctenediyl)Co(η-9-SMe2-7,8-C2B9H10 and [(η22-cyclooctadiene)Co((η-1,2,4,5-C6H2Me4)]BF4 were determined by X-ray diffraction analysis.  相似文献   

16.
The monoxides [Fe(η5-C5Me4PPh2)(η5-C5Me4P{O}Ph2)] (1) and [Os(η5-C5H4PPh2)(η5-C5H4P{O}Ph2)] (2) have been prepared by treatment of the corresponding diphosphines with CCl4 and methanol.These ligands react with [Pd(PhCN)2Cl2] to give dichloride complexes of different structure.The dimeric complex [{Os(η5-C5H4PPh2)(η5-C5H4P{O}Ph2)}PdCl(μ-Cl)]2 (4) contains the monodentate P-coordinated osmocene ligand with the free P{O}Ph2 group, while the octamethylferrocene ligand gives the chelate k2-P,O complex [{Fe(η5-C5Me4PPh2)(η5-C5Me4P{O}Ph2)}PdCl2] (3).The structures of 3 and 4 have been determined crystallographically.Treatment of 3 and 4 with silver salts in CH2Cl2 or acetonitrile leads to the corresponding dicationic complexes[{M(η5-C5R4PPh2)(η5-C5R4P{O}Ph2)}Pd(MeCN)x]2+ (5, M = Fe, R = Me; 6, M = Os, R = H). Complex 5 decomposes upon isolation, in contrast 6 is rather stable, probably due to Os-Pd bonding. The dichlorides 3 and 4 catalyze catalytic amination of p-bromotoluene with N-(4-tolyl)morpholine with lower activity than (dppf)PdCl2, however they perform comparable to (dppf)PdCl2 activity in coupling of p-bromotoluene with p-methoxyphenyl boronic acid.  相似文献   

17.
Heteroleptic rhodium(I) complexes with the general formulations [(η4-C8H12)Rh(L)] [η4-C8H12 = 1,5-cyclooctadiene; L = 5-(4-cyanophenyl)dipyrromethene, cydpm; 5-(4-nitrophenyl)dipyrromethene, ndpm; and 5-(4-benzyloxyphenyl)dipyrromethene, bdpm; 5-(4-pyridyl)dipyrromethene, 4-pyrdpm; 5-(3-pyridyl)dipyrromethene, 3-pyrdpm] have been synthesized. The complex [(η4-C8H12)Rh(4-pyrdpm)] have been used as a synthon in the construction of homo-bimetallic complex [(η4-C8H12)Rh(μ-4-pyrdpm)Rh(η5-C5Me5)Cl2] and hetero-bimetallic complexes [(η4-C8H12)Rh(μ-4-pyrdpm)Ir(η5-C5Me5)Cl2], [(η4-C8H12)Rh(μ-4-pyrdpm)Ru(η6-C10H14)Cl2] and [(η4-C8H12)Rh(μ-4-pyrdpm)Ru(η6-C6H6)Cl2]. Resulting complexes have been characterized by elemental analyses and spectral studies. Molecular structures of the representative mononuclear complexes [(η4-C8H12)Rh(ndpm)] and [(η4-C8H12)Rh(4-pyrdpm)] have been authenticated crystallographically.  相似文献   

18.
Reaction of [(CpV)2(B2H6)2], 1 (Cp = η5-C5H5) with four equivalents of [Co2(CO)8] or [Co4(CO)12] in hexane at 70 °C leads to the isolation of the tetranuclear carbonyl cluster, [(η6-C6H5OCo)Co3(CO)9], 2 in modest yield. The geometry of 2 is similar to that of [Co4(CO)12] where all the four Co atoms are arranged in a tetrahedral geometry. The apical cobalt atom in 2 is coordinated to C6H5O ring in a η6-fashion and the other three cobalt atoms are each coordinated to three carbonyl ligands. Compound 2 has been characterized in solution by IR, 1H, 13C NMR and mass spectrometry and the structural types were unequivocally established by crystallographic analysis.  相似文献   

19.
The synthesis and characterization of pyrazole derivatives of general formula [C6H4-4-R-1-{(3,5-Me2-C3N2)-CH2-(η5-C5H4)Fe(η5-C5H5)}] [R = OMe (1a) or H (1b)] with a ferrocenylmethyl substituent are described.The study of the reactivity of compounds 1 with palladium(II) acetate has allowed the isolation of complexes (μ-AcO)2[Pd{κ2-C,N-C6H3-4-R-1-[(3,5-Me2-C3N2)-CH2-(η5-C5H4)Fe(η5-C5H5)]}]2 (2) [R = OMe (2a) or H (2b)] that contain a bidentate [C(sp2, phenyl), N] ligand and a central “Pd(μ-AcO)2Pd” unit.Furthermore, treatment of 2 with LiCl produced complexes (μ-Cl)2[Pd{κ2-C,N-C6H3-4-R-1-[(3,5-Me2-C3N2)-CH2-(η5-C5H4)Fe(η5-C5H5)]}]2 (3) [R = OMe (3a) or H (3b)] that arise from the replacement of the acetato ligands by the Cl.Compounds 2 and 3 also react with PPh3 giving the monomeric complexes [Pd{κ2-C,N-C6H3-4-R-1-[(3,5-Me2-C3N2)-CH2-(η5-C5H4)Fe(η5-C5H5)]}X(PPh3)] {X = AcO and R = OMe (5a) or H (5b) or X = Cl and R = OMe (6a) or H (6b)}, where the phosphine is in a cis-arrangement to the metallated carbon atom. Treatment of 3 with thallium(I) acetylacetonate produced [Pd{κ2-C,N-C6H3-4-R-1-[(3,5-Me2-C3N2)-CH2-(η5-C5H4)Fe(η5-C5H5)]}(acac)] (7) [R = OMe (7a) or H (7b)]. Electrochemical studies of the free ligands and the cyclopalladated complexes are also reported. The dimeric complexes 3 also react with MeO2C-CC-CO2Me (in a 1:4 molar ratio) giving [Pd{(MeO2C-CC-CO2Me)2C6H3-4-R-1-[(3,5-Me2-C3N2)-CH2-(η5-C5H4)Fe(η5-C5H5)]}Cl] (8) [R = OMe (8a) or H (8b)], which arise from the bis(insertion) of the alkyne into the σ{Pd-C(sp2, phenyl)} bond of 3.  相似文献   

20.
在溶剂热条件下, 以原位反应为基础合成了两个碘化物(C6H8N3)+I3-(1, C6H8N3=2,3-dihydroimi-dazo[1,2-a]pyrimidin-1-ium, 2,3-二氢咪唑[1,2-α]-嘧啶鎓阳离子)和[(Cu3I4)(C8H17N2)](2, C8H17N2=N-ethyl-4-aza-1-azonia-bicyclo[2.2.2]octane, N-乙基三乙烯二铵阳离子). 用元素分析、粉末X射线衍射及单晶X射线衍射等对化合物进行了表征. 结果表明, 化合物1属于三斜晶系, P1空间群, a=0.74281(15) nm, b=0.84241(17) nm, c=0.9993(2) nm, α=82.02(3)°, β=83.30(3)°, γ=82.92(3)°, V=0.6114(2) nm3. 化合物2属于单斜晶系, P21/c空间群, a=0.68924(14) nm, b=1.0786(2) nm, c=2.2779(5) nm, β=94.84(3)°, V=1.6874(6) nm3. 在两个化合物合成中存在两种不同类型的配体原位合成反应, 即化合物1的2-氨基嘧啶和乙醇的成环反应与化合物2的三乙烯二胺和乙醇的烷基化反应.  相似文献   

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