Reaction of diazonium salts with transition metals : IX. Reaction of vinyltrimethylsilane with arenediazonium tetrafluoroborates under palladium(0) catalysis

Arenediazonium tetrafluoroborates (ArN₂BF₄ where Ar=Ph, 4-MeC₆H₄, 4-BrC₆H₄, 4-IC₆H₄ and 4-NO₂C₆H₄) reacted easily with CH₂=CHSiMe₃ at 25 δC to give ArCH=CH₂, (E-ArCH=CHSiMe₃ and Ar(Me₃Si)C=CH₂ in excellent yields under palladium(O) catalysis. (E)-ArCH=CHSiMe₃ compounds were obtained predominantly and isolated in good yields by using an excess of CH₂=CHSiMe₃ over ArN₂BF₄. Protodesilylation of the reaction mixture afforded styrene derivatives.     

氯合间取代四苯基卟啉铁与咪唑类配体配位反应的热力学研究

用紫外可见光谱法,在ＤＭＳＯ中测量了氯合间取代四苯基铁卟啉与多种咪唑类配体反应的平衡常数,研究了卟啉环上取代基、反应温度以及配体等因素对反应平衡常数的影响。利用温度系数法测定了反应体系的热力学函数ΔｒＨｍ和ΔｒＳｍ。     

抗白血病药物克拉屈滨的合成

报道了抗白血病药物克拉屈滨的合成新方法:在NaH作用下,廉价易得的6-氯嘌呤高选择性地在β位和1-氯-2-脱氧-3,5-二-O-对氯苯甲酰基-D-核糖缩合;β-缩合物的2位在三氟乙酸酐和四丁基硝酸铵作用下引入硝基;在NH₄Cl/EtOH作用下,2-硝基转化为2-氯;最后在饱和NH₃/CH₃OH溶液中完成保护基脱除和6-氯氨解两步反应,以4步共43.5%的总收率得到抗白血病药物克拉屈滨。 该方法完全避免了α异构体的生成,原料廉价易得,分离纯化不需柱层析,且反应扩大到100 g规模时,收率无下降,具有较好的应用前景。     

Mesogenic behaviour of two series of orthopalladated polar inline derivatives and their organic ligands (II)

One series of 4-n-octyl-N-(4-X-benzylidene)anilines and two series of polar orthopalladated complexes derived from these of type Pd₂(μ-Y)₂ p-X-C₆H₃-CH = N-C₆H₄-C₈H₁₇₂; X: -H, -F, -Cl, -Br, -NO₂, -CN, -CH₃, -OCH₃, -CF₃, -COOCH₃, -OCOCH₃ and -OCOQH₅; Y: -OAc and -Cl; have been synthesized and their mesogenic properties studied. In the polar Schiff bases used as organic ligands, the polar end group determines both the presence of the mesophase and the type of mesophase exhibited. In the complexes, however, it is the central structure of the molecule that practically always determines mesogenic behaviour. No acetato-bridged complex is mesogenic. All the chloro-bridged complexes, however, show mesogenic behaviour. All these compounds show smectic A mesophases with the exception of the CN compound, which only exhibits a nematic mesophase.     

稀土Pr(Ⅲ)、Nd(Ⅲ)与2-[(取代苯胺基)羰基]苯甲酸的配合物研究

报道了配合物Ln(X-P)₃·3H₂O[其中X=H,2-Cl,4-Br,3-OH,3-NO₂,2-OCH₃,2-CH₃,2,4-二氯,P=2-(COO)C₆H₄CONHC₆H_5-nX_n,n=1,2;Ln=Pr(Ⅲ),Nd(Ⅲ)]的制备,并用元素分析、红外光谱、电子反射光谱、热重分析进行了表征。结果表明,配位是通过羧酸羟基氧原子和酰胺羰基氧原子进行的,含3分子配位水。通过电子反射光谱数据,对Slater-Condon参量(F_k)、Lande参量(ξ_4f)、Nephelauxit比率(β),平均共价参数(δ)、平均成键参数(b^1/2)、F₄/F₂、F₆/F₂比值进行了计算,对配合物的共价成键情况进行了讨论。     

N-苯基硫代膦酰基氨基酸及氨基乙酸乙酯衍生物的研究

本文报告了42个新的N-苯基硫代膦酰基氨基酸及氨基乙酸乙酯衍生物的制备;改进了N-膦酰基氨基酸酯衍生物的制备方法;对衍生物的生物活性以及某些衍生物在酸碱水溶液中的稳定性进行了初步探讨。     

Selective spectrophotometric determination of palladium(II) with 2(5-nitro-2-pyridylazo)-5-(N-propyl-N-3-sulfopropylamino)phenol(5-NO(2).PAPS) and tartaric acid with 5-NO(2).PAPS-niobium(V) complex

Spectrophotometric determinations of palladium(II) and tartaric acid were respectively investigated by using the color reactions between 2(5-nitro-2-pyridylazo)-5-(N-propyl-N-3-sulfopropylamino)phenol(5-NO₂.PAPS) and palladium(II) in strong acidic media, and between 5-NO₂.PAPS, niobium(V) tartaric acid in weak acidic media. The calibration graphs were linear in the range of 0–25 μg/10 ml palladium(II), with an apparent molecular coefficient () of 6.2×10⁴ l mol⁻¹ cm⁻¹ at 612 nm, and 0–23 μg/10 ml tartaric acid with =1.08×10⁶ l mol⁻¹ cm⁻¹ at 612 nm, respectively. The proposed methods were selective and sensitive in comparison with other chelating pyridylazo dyes–palladium(II) or metavanadic acid–tartaric acid method, and the effect of foreign ions such as copper(II) was negligible for the assay of palladium(II) with 5-NO₂.PAPS.     

Inverse phase transfer catalysis: kinetics of the pyridine-1-oxide-catalyzed two-phase reactions of methyl-, methoxy-, iodo-, and nitro-benzoyl chlorides and benzoate ions

The substitution reactions of XC₆H₄COCl [X=2-, 3-, or 4-CH₃; 2-, 3-, or 4-CH₃O; 2-, or 4-I; or 2-, 3-, or 4-NO₂] and YC₆H₄COONa [Y=2-, 3-, or 4-CH₃; 2-, 3-, or 4-CH₃O; 2-I; 4-NO₂; or H] in a two-phase H₂O/CH₂Cl₂ medium using pyridine-1-oxide (PNO) as an inverse phase transfer catalyst were investigated. In general, the kinetics of the reaction follows a pseudo-first-order rate law, with the observed rate constant being a linear function of the concentration of PNO in the water phase. In contrast to other analogous reactions, the hydrolysis reaction of 2-, 3-, or 4-NO₂C₆H₄COCl in H₂O/CH₂Cl₂ medium is catalyzed considerably by PNO and reaches an equilibrium. In the PNO-catalyzed reaction of XC₆H₄COCl and XC₆H₄COONa in H₂O/CH₂Cl₂ medium, the order of reactivities of XC₆H₄COCl toward reaction with PNO in CH₂Cl₂ is 2-IC₆H₄COCl>4-IC₆H₄COCl>(C₆H₅COCl,3-CH₃OC₆H₄COCl)>3-CH₃C₆H₄COCl>(2-CH₃C₆H₄COCl,4-CH₃C₆H₄COCl)>4-CH₃OC₆H₄COCl>2-CH₃OC₆H₄COCl. Combined with the results of other analogous reactions, good Hammett correlations with positive reaction constant were obtained for the meta- and para-substituents, which supports that the XC₆H₄COCl–PNO reaction in CH₂Cl₂ is a nucleophilic substitution reaction.     

某些不对称的双偶氮变色酸衍生物和稀土元素的络合反应

本文研究了含有助色团-COCH₃、-NO₂、-SO₃H的18个不对称双偶氮变色酸衍生物和稀土元素的络合行为。讨论了助色团-COCH₃、-NO₂、-SO₃H和它们所取代的位置对络合物的性能和组成的影响。     

The preparation and characterization of TlClBrI complexes. X-ray crystal structure of chlorobromoiodo-bis-(triphenylphosphine oxide)thallium(III)

The complexes TlClBrI·L₂ (L = C₅H₅NO, 2-, 3-, 4-CH₃C₅H₄NO, 4-ClC₅H₄NO, 4-CNC₅H₄NO, 4-NO₂C₅H₄NO, 4-CH₃OC₅H₄NO, HMPA and OPPh₃) have been prepared and characterized by elemental analysis. The solids behave as non-electrolytes in acetonitrile solution and are monomers in benzene. The structure of TlClBrI(OPPh₃)₂ has been determined by X-ray crystallography and refined to a conventional R factor of 0.05. This compound crystallizes in the monoclinic space group P2₁/c and a = 14.742(5), b = 14.418(3), c = 17.234(4) Å, β = 107.54(2)° and Z = 4. The structure consists of neutral monomeric complexes in which the thallium atom shows a five-fold coordination in the form of a distorted trigonal bipyramid, the halogen atoms being located in the equatorial plane. ¹H NMR and vibrational (IR and Raman) spectra of all of these complexes are discussed on the basis of this structure.     

四甲基双硅桥联环戊二烯基稀土金属有机配合物的合成及[Me4Si2(C5H4)2Sm(μ-Cl)(THF)]2的晶体结构研究

四甲基双硅桥联环戊二烯基钠与无水三氯化稀土在THF溶剂中反应合成了标题配合物Me₄Si₂(C₅H₄)₂LnCl[Ln:3Nd,4Sm,5Gd,6Y]和配合物Me₄Si₂(C₅H₄):Ln(C₅H₅)(THF)n[Ln:1La,n=1;2Pr,n=0].通过元素分析、¹HNMR、13CNMR和MS确证了配合物的结构,在THF溶液中重结晶获得配合物4的单晶,x射线衍射证明晶体结构为二聚体,4为单斜晶系,空间群为P2₁/c,晶体学数据a=1.2982(3)nm,b=1.2269(3)nm,c=1.3681(2)nm,β=96.79(2)°,V=2.162(1)nm³,Z=2,D_x=1.53g/cm³,偏差因子R=0.068.     

四甲基二硅氧基桥联双环戊二烯基稀土金属配合物的合成及结构研究

在严格的无水无氧条件下无水NdCl₃和SmCl₂与Na₂(C₅H₄SiMe₂)₂O以1:1摩尔比在四氢呋喃溶液中反应,得标题配合物[O(Me₂SiC₅H₄)₂Ln(μ-Cl)(THF)]₂[Ln=Nd(1),Sm(2)].元素分析证明配合物1和2的组成.X射线衍射分析证明1和2是通过氯原子桥联的二聚体结构.     

Ring-opening metathesis polymerization of norbornene and norbornadiene by tungsten(II) and molybdenum(II) complexes

The reaction of norbornene (NBE) and norbornadiene (NBD) in the presence of seven-coordinate tungsten(II) and molybdenum(II) complexes of the [(CO)₄M(μ-Cl)₃M(SnCl₃)(CO)₃] and [MCl(M′Cl₃)(CO)₃(NCMe)₂] (M=W, Mo; M′=Sn, Ge) types leads to ring-opening metathesis polymerization (ROMP) and to the formation of high molecular weight polymers. The geometric structure of these polymers was determined by means of ¹H- and ¹³C-NMR spectroscopy. The monitoring of the reaction between cyclic olefins and the metal complex by means of ¹H-NMR spectroscopy allowed us to observe the coordination of NBD to metal atoms in the initiation step of the polymerization process. Compounds of the [MCl(SnCl₃)(CO)₃(η⁴-NBD)] type prepared directly from [(CO)₄M(μ-Cl)₃M(SnCl₃)(CO)₃] or [MCl(M′Cl₃)(CO)₃(NCMe)₂] (M=W, Mo) in the presence of an excess of NBD initiate the ROMP reaction immediately. The detection of the first-formed products in the reaction between the metal complex and cyclic olefins provides valuable information concerning the nature of the initiating species.     

N,N′-bis(substituted-phenyl)oxamides and their dinuclear pentacoordinate nickel(II) complexes

The preparation, spectroscopic characterization and magnetic study of N,N′-bis(substituted-phenyl)oxamidate-bridged nickel(II) dinuclear complexes of formula {[Ni(N₃-mc)]₂(μ-CONC₆H₄-X)}(PF₆)₂ (N₃-mc = 2,4,4-trimethyl-1,5,9-triazacyclo-dodec-1-ene (Me₃-N₃-mc) or 2,4,4,9-tetramethyl-1,5,9-triazacyclododec-1-ene (Me₄-N₃-mc), X = 2-Cl, 4-Cl, 2-OCH₃, 4-OCH₃) are reported. These paramagnetic nickel(II) complexes have been characterized by both one- and two-dimensional (COSY) ¹H NMR techniques. The COSY spectrum of 5 has allowed to achieve the assignment of the phenyl protons of the N,N′-diphenyloxamidate. The crystal structures of [Ni(Me₃-N₃-mc)(μ-CONC₆H₄-4-Cl)]₂(PF₆)₂ (6), [Ni(Me₃-N₃-mc)(μ-CONC₆H₄-4-OMe)]₂(PF₆)₂ (8) and [Ni(Me₄-N₃-mc)(μ-CONC₆H₄-2-Cl)]₂(PF₆)₂ (9) have been determined and their magnetic properties have been studied. The value of magnetic coupling between the two nickel(II) ions across the oxamidate bridge [J = − 37.6 (6), −39.9 (8) and −39.7 cm⁻¹ (9)] is sensitive to the distortion of the coordination sphere of the metal ions and the topology of the molecular bridge.     

Mechanistic investigation of intramolecular aminoalkene and aminoalkyne hydroamination/cyclization catalyzed by highly electrophilic, tetravalent constrained geometry 4d and 5f complexes. Evidence for an M-N sigma-bonded insertive pathway

A mechanistic study of intramolecular hydroamination/cyclization catalyzed by tetravalent organoactinide and organozirconium complexes is presented. A series of selectively substituted constrained geometry complexes, (CGC)M(NR2)Cl (CGC = [Me2Si(eta5-Me4C5)(tBuN)]2-; M = Th, 1-Cl; U, 2-Cl; R = SiMe3; M = Zr, R = Me, 3-Cl) and (CGC)An(NMe2)OAr (An = Th, 1-OAr; An = U, 2-OAr), has been prepared via in situ protodeamination (complexes 1-2) or salt metathesis (3-Cl) in high purity and excellent yield and is found to be active precatalysts for intramolecular primary and secondary aminoalkyne and aminoalkene hydroamination/cyclization. Substrate reactivity trends, rate laws, and activation parameters for cyclizations mediated by these complexes are virtually identical to those of more conventional (CGC)MR2 (M = Th, R = NMe2, 1; M = U, R = NMe2, 2; M = Zr, R = Me, 3), (Me2SiCp' '2)UBn2 (Cp' ' = eta5-Me4C5; Bn = CH2Ph, 4), Cp'2AnR2 (Cp' = eta5-Me5C5; R = CH2SiMe3; An = Th, 5, U, 6), and analogous organolanthanide complexes. Deuterium KIEs measured at 25 degrees C in C6D6 for aminoalkene D2NCH2C(CH3)2CH2CHCH2 (11-d2) with precatalysts 2 and 2-Cl indicate that kH/kD = 3.3(5) and 2.6(4), respectively. Together, the data provide strong evidence in these systems for turnover-limiting C-C insertion into an M-N(H)R sigma-bond in the transition state. Related complexes (Me2SiCp' '2)U(Bn)(Cl) (4-Cl) and Cp'2An(R)(Cl) (R = CH2(SiMe3); An = Th, 5-Cl; An = U, 6-Cl) are also found to be effective precatalysts for this transformation. Additional arguments supporting M-N(H)R intermediates vs M=NR intermediates are presented.     

Interaction of half-sandwich alkylmolybdenum(III) complexes with B(C6F5)3. The X-ray structure of [CpMo(η-C4H6)(μ-Cl)(μ-CH2)(O)MoCp][CH3B(C6F5)3]

The reactions of the half-sandwich molybdenum(III) complexes CpMo(η⁴-C₄H₄R₂)(CH₃)₂, where Cp=η⁵-C₅H₅ and R=H or CH₃, with equimolar amounts of B(C₆F₅)₃ have been investigated in toluene. EPR monitoring shows the formation of an addition product which does not readily react with Lewis bases such as ethylene, pyridine, or PMe₃. The analysis of the EPR properties and the X-ray structure of a decomposition product obtained from dichloromethane, [CpMo(η⁴-C₄H₆)(μ-Cl)(μ-CH₂)(O)MoCp][CH₃B(C₆F₅)₃], indicate that the borane attack has occurred at the methyl position.     

P and C NMR investigation of the system tetracarbonyldi-μ-chlorodirhodium(I) — tertiary phosphine

¹³C and ³¹P{¹H} NMR data at low temperature prompted us to characterize cis-[Rh(CO)₂(PR₃)Cl] (3) (3a, PR₃ = PPh₃; 3b, PR₃ = PMe₂Ph), as surprisingly stable products of the reaction between [{Rh(CO)₂(μ-Cl)}₂] (1) and tertiary phosphines in toluene (P : Rh = 1). Every attempt to isolate solid 3a led to the cis- and trans- halide-bridged dimers [{Rh(CO)₂(μ-Cl)}₂] (5a) and 6a which are formed from 3a by slow decarbonylation, a process which is greatly accelerated by the evaporation of the solvent under vacuum.

The analogous reaction of 1 with dimethylphenylphosphine follows a similar pathway; in this case, however, low temperature NMR spectra allowed us to characterize the pentacoordinated dinuclear species [{Rh(CO)₂(μ-Cl)}₂] (2b) as the unstable intermediate of the bridge-splitting process.

The reaction of 3 with a second equivalent of phosphine (P : Rh = 2) leads, at room temperature, to the well known product trans-[Rh(CO)(PR₃)₂Cl] (8) accompanied by evolution of CO; however our data show that when the reaction is performed at 200 K, decarbonylation is prevented and spectroscopic evidence of trigonal bipyramidal pentacoordinate [Rh(CO)₂(PR₃)₂Cl] (7), stable only at low temperature, can be obtained.     

Heterobimetallic Mo---Sn complexes. Reactions of [Mo(CO)3(CH3CN)2(Cl)(SnRCl2)] (R = Me, Ph) with 4(4-XC6H4)3 (X = Cl, F, H, Me, MeO)

Three families of heterobimetallic compounds were obtained by reaction of [Mo(CO)₃(CH₃CN)₂(Cl)(SnRCl₂)] (R = Ph, Me) with P(4-XC₆H₄)₃ (X = Cl, F, H, Me, MeO). The type of compound obtained dependent on the solvent and concentration of the starting compound. So, [Mo(CO)₂(CH₃COCH₃)₂(PPh₃)(Cl)(SnRCl₂)]·nCH₃COCH₃ (R = Ph, n = 0.5; R = Me, n = 1) (type I) and [Mo(CO)₃{P(4-XC₆H₄)₃}(μ-Cl)(SnRCl₂)]₂ (R = Ph, X = Cl, F, H, Me, MeO; R = Me, X = Cl, F) (type II) were isolated from acetone solution in ca 0.05 M and 0.1 M concentrations, respectively. However, [Mo(CO)₃(CH₃CN) {P(4-XC₆H₄)₃}(Cl)(SnRCl₂)] (R = Ph, X = H; R = Me, X = Cl, F, H) (type III) were obtained from dichloromethane solution independently of the concentration used. All new complexes showed a seven-coordinate environment at molybdenum, containing Mo---Cl and Mo---Sn bonds. Mössbauer spectra indicated a four-coordination at tin for type III complexes.     

Electron paramagnetic resonance study of the reactions of tetrathiomolybdate with roussin salts and esters, and with some related iron nitrosyls

The tetrathiomolybdate ion [MoS₄]²⁻ reacts in DMF solution with Roussin esters Fe₂(SR)₂(NO)₄ (R = Me, Et, n-Pr, i-Pr, n-Bu,t-Bu, n-C₅H₁₁) to yield the paramagnetic iron nitrosyls [Fe(NO)₂(SR)₂]⁻ (1), [Fe(NO)₂(S₂MoS₂]⁻ (2) and [Fe(NO)(S₂MOS₂)₂]⁻ (3). The new complexes (2) and (3) have been characterized by EPR spectroscopy and the assignment to them of constitutions based respectively upon tetrahedral and square pyramidal iron is supported by EHMO calculations. Fe₂(SPh)₂(NO)₄ with [MoS₄]²⁻ yields only [Fe(NO)₂(SPh)₂]⁻, and preformed (3) reacts with PhS⁻ to give firstly EPR-silent species, and then [Fe(NO)₂(SPh)₂]⁻. The mononitrosyl (3) can also be formed by reaction of [MoS₄]²⁻ with [Fe₄S₃(NO)₇]⁻, Fe₄S₄(NO)₄, or Fe₂I₂(NO)₄.     

A new dirbenium complex with an unsupported bridging hydride ligand

The reaction of Re₂(CO)₈(μ-H)2 with CH₂(NMe₂)₂ in chloroform at 25°C yielded the new compound Re₂(CO)₈(NHMe₂)(Cl)(μ-H) (1) in 31% yield. Compound 1 was characterized by IR, ¹H NMR and a single-crystal X-ray diffraction analysis. Crystal data: orthorhombic, Pbca, a = 13.787(4), b = 19.884(5), c = 12.296(2) Å. Solution by direct methods (MITHRIL), R = 0.035 for 1800 reflections. The complex contains two rhenium atoms linked by an unsupported hydride bridge, Re Re = 3.362(1) Å, Re(1)---H = 1.8(1) Å and Re(2)---H = 2.0(1) Å. A chloride ligand abstracted from the solvent is terminally bonded to Re(1), and a dimethylamine ligand abstracted from the CH₂(NMe₂)₂ is coordinated to Re(2). When heated to 68°C, the dimethylamine ligand was eliminated and the chloride ligand became a bridge in the new compound Re₂(CO)₈(μ-H)(μ-Cl) (2), yield 76%.