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1.
This paper presents a new convenient route to prepare osmafuran starting from readily accessible HC≡CCH(OH)C≡CH and OsHCl(CO)(PPh3)3. Treatment of a solution of OsHCl(CO)(PPh3)3 in dichloromethane with HC≡CCH(OH)C≡CH, followed by the addition of acetic acid, produced osmafuran [Os(CHC(PPh3)CO(CH2CH3))Cl(CO)(PPh3)2]Cl (2). 2 has been isolated in good yield and fully characterized. 1H and 13C NMR spectra show the characteristic downfield chemical shifts of the ring hydrogen and carbon atoms. NMR and X-ray diffraction data provide strong evidence for the aromatic nature of 2. Probably due to the effect of the phosphonium substituent, 2 exhibits remarkable thermal stability, air stability and lower reactivity. 相似文献
2.
The reactions of phosphonium‐substituted metallabenzenes and metallapyridinium with bis(diphenylphosphino)methane (DPPM) were investigated. Treatment of [Os{CHC(PPh 3)CHC(PPh 3)CH}Cl 2(PPh 3) 2]Cl with DPPM produced osmabenzenes [Os{CHC(PPh 3)CHC(PPh 3)CH}Cl 2{(PPh 2)CH 2(PPh 2)}]Cl ( 2 ), [Os{CHC(PPh 3)CHC(PPh 3)CH}Cl{(PPh 2)CH 2(PPh 2)} 2]Cl 2 ( 3 ), and cyclic osmium η 2‐allene complex [Os{CH?C(PPh 3)CH?(η 2‐C?CH)}Cl 2{(PPh 2)CH 2(PPh 2)} 2]Cl ( 4 ). When the analogue complex of osmabenzene 1 , ruthenabenzene [Ru{CHC(PPh 3)CHC(PPh 3)CH}Cl 2(PPh 3) 2]Cl, was used, the reaction produced ruthenacyclohexadiene [Ru{CH?C(PPh 3)CH?C(PPh 3)CH}Cl{(PPh 2)CH 2(PPh 2)} 2]Cl 2 ( 6 ), which could be viewed as a Jackson–Meisenheimer complex. Complex 6 is unstable in solution and can easily be convert to the cyclic ruthenium η 2‐allene complexes [Ru{CH?C(PPh 3)CH?(η 2‐C?CH)}Cl{(PPh 2)CH 2(PPh 2)} 2]Cl 2 ( 7 ) and [Ru{CH?C(PPh 3)CH?(η 2‐C?CH)}Cl 2{(PPh 2)CH 2(PPh 2)} 2]Cl ( 8 ). The key intermediates of the reactions have been isolated and fully characterized, further supporting the proposed mechanism for the reactions. Similar reactions also occurred in phosphonium‐substituted metallapyridinium [OsCl 2{NHC(CH 3)C(Ph)C(PPh 3)CH}(PPh 3) 2]BF 4 to give the cyclic osmium η 2‐allene‐imine complex [OsCl 2{NH?C(CH 3)C(Ph)?(η 2‐C?CH)}{(PPh 2)CH 2(PPh 2)}(PPh 3)]BF 4 ( 11 ). 相似文献
3.
利用原位 1H和 31P NMR对单氢钌配合物TpRu(PPh 3)(CH 3CN)H [Tp=hydrotris(pyrazolyl)borate]与H 2O和酸性HOCH 2CF 3的反应进行了研究, 结果显示相应的反应产物分别是TpRu(PPh 3)(CH 3CN)(OH) 和TpRu(PPh 3)(CH 3CN)(OCH 2CF 3). 观察到反应过程中Ru-H…HOH和Ru-H…HOCH 2CF 3分子间的氢键作用. 提出了生成TpRu(PPh 3)(CH 3CN)(OH)和TpRu(PPh 3)(CH 3CN)(OCH 2CF 3)的不同作用机理. 在水存在下, TpRu(PPh 3)(CH 3CN)H 与H 2O反应, 经过中间体TpRu(PPh 3)(H 2O)H和TpRu(PPh 3)(OH)(η 2-H 2)生成产物TpRu(PPh 3)(CH 3CN)(OH). 而TpRu(PPh 3)(CH 3CN)H与酸性HOCH 2CF 3反应时, 单氢配体被质子化形成中间体[TpRu(PPh 3)(CH 3CN)- (η 2-H 2)](OCH 2CF 3), 进而转变成产物TpRu(PPh 3)(CH 3CN)(OCH 2CF 3). TpRu(PPh 3)(CH 3CN)(OCH 2CF 3)与H 2作用, 经中间体TpRu(PPh 3)(HOCH 2CF 3)H生成TpRu(PPh 3)(η 2-H 2)H. 相似文献
4.
Abstract Treatment of ethyl oxalyl chloride or methyl oxalyl chloride with lithium diisopropyl(carboethoxyfluoromethyl)phosphonate[(i-PrO) 2P(O)CFCO 2Et] ?Li + 2 followed by in siru nucle-ophilic addition with methylmagnesium iodide or vinyl magnesium bromide affords with exclusive E-stereoselectivity formation of diethyl-2-fluoro-3-methyl fumarate (CH 3)(C0 2Et)C[dbnd]CFCO 2Et 4 or 75% of the E-isomer of a-fluoro-P-vinyl-a,P-unsaturated diester (E,Z)-(CH 2[dbnd]CH)(CO 2C 2H 5)C[dbnd]CFCO 2Et 5, respectively. However, direct reaction of ethyl pyruvate with 2 gives the fluoro-olefin (CH 3)(CO 2Et)C[dbnd]CFCO 2Et 4 with 79% E-stere-oselectivity. The E/Zratio of (CH 2[dbnd]CH)(CO 2Et)C[dbnd]CFCO 2Et 5 depends on the HMFT or DMPU cosolvents present in the reaction mixture. 相似文献
5.
A straightforward method for the preparation of metallo carbosiloxanes of type Si(OCH 2CH 2CH 2SiMe 2[OCH 2PPh 2M(CO) n]) 4 ( n = 3, M = Ni, 7a; n = 4, M = Fe, 7b; n = 5: M = Mo, 7c; M = W, 7d), Si(OCH 2CH 2CH 2SiMe[OCH 2PPh 2Ni(CO) 3] 2) 4 ( 8) and Me 2Si(OCH 2CH 2CH 2SiMe[OCH 2PPh 2Ni(CO) 3] 2) 2 ( 11) is described. The reaction of Si(OCH 2CH 2CH 2SiMeXCl) 4 ( 1: X = Me, 2: X = Cl) or Me 2Si(OCH 2CH 2CH 2SiMeCl 2) 2 ( 9) with HOCH 2PPh 2 ( 3) produces Si(OCH 2CH 2CH 2SiMe 2(OCH 2PPh 2)) 4 ( 4), Si(OCH 2CH 2CH 2SiMe(OCH 2PPh 2) 2) 4 ( 5) or Me 2Si(OCH 2CH 2CH 2SiMe(OCH 2PPh 2) 2) 2 ( 10) in presence of DABCO. Treatment of the latter molecules with Ni(CO) 4 ( 6a), Fe 2(CO) 9 ( 6b), M(CO) 5(Thf) ( 6c: M = Mo; 6d: M = W), respectively, gives the title compounds 7a- 7d, 8 and 11 in which the PPh 2 groups are datively bound to a 16-valence-electron metal carbonyl fragment.The formation of analytical pure and uniform branched and dendritic metallo carbosiloxanes is based on elemental analysis, and IR, 1H, 13C{ 1H}, 29Si{ 1H} and 31P{ 1H} NMR spectroscopic studies. In addition, ESI-TOF mass spectrometric studies were carried out. 相似文献
6.
Treatment of the osmabenzene [Os{CHC(PPh 3)CHC(PPh 3)CH} Cl 2(PPh 3) 2]Cl ( 1 ) with excess 8‐hydroxyquinoline produces monosubstituted osmabenzene [Os{CH C(PPh 3) CHC(PPh 3)CH}(C 9H 6NO)Cl(PPh 3)]Cl ( 2 ) or disubstituted osmabenzene [Os{CHC(PPh 3)CHC(PPh 3)CH} (C 9H 6NO) 2]Cl ( 3 ) under different reaction conditions. Osmabenzene 2 evolves into cyclic η 2‐allene‐coordinated complex [Os{CH?C(PPh 3)CH=(η 2‐C?CH 2)}(C 9H 6NO)(PPh 3) 2]Cl ( 4 ) in the presence of excess PPh 3 and NaOH, presumably involving a P? C bond cleavage of the metallacycle. Reaction of 4 with excess 8‐hydroxyquinoline under air affords the S NAr product [(C 9H 6NO)Os{CHC(PPh 3)CHCHC} (C 9H 6NO)(PPh 3)]Cl ( 5 ). Complex 4 is fairly reactive to a nucleophile in the presence of acid, which could react with water to give carbonyl complex [Os{CH?C(PPh 3)CH?CH 2}(C 9H 6NO) (CO)(PPh 3) 2]Cl ( 6 ). Complex 4 also reacts with PPh 3 in the presence of acid and results in a transformation to [Os {CHC(PPh 3)CHCHC}(C 9H 6NO)Cl (PPh 3) 2]Cl ( 7 ) and [Os{CH?C(PPh 3) CH=(η 2‐C?CH(PPh 3))}(C 9H 6NO) Cl(PPh 3)]Cl ( 8 ). Further investigation shows that the ratio of 7 and 8 is highly dependent on the amount of the acid in the reaction. 相似文献
7.
Copper(II) and palladium(II) complexes with 15-membered asymmetric 5,9-dihydro-2,4,10,12-tetramethyl-1,5,9,13-monobenzotetraazacyclo[15]tetradecine have been synthesized and characterized. The electrochemical behaviors of the complexes showed a reduction and two one-electron irreversible oxidation waves in given potential ranges due to the metal ion and macrocycle ring, respectively. The electrocatalytic reduction of dioxygen on glassy carbon electrodes electropolymerized by such 15-membered and 14-membered tetraazaannulene complexes occurred at 160–280 mV (versus SCE), less negative than on the bared one at pH 7.0. The catalytic activities of the copper(II) complexes in the oxidation of p-Xstyrene (X = OCH 3, CH 3, H, F, Cl) were higher than those of the palladium(II) ones. The structures of the 15-membered copper(II) and palladium(II) complexes were determined using the X-ray diffraction method. 相似文献
8.
A 1:1 reaction of [HO(CH 2) 3] 3P with 4-hydroxy-3-methoxy-cinnamaldehyde (coniferaldehyde) or 3,5-dimethoxy-4-hydroxycinnamaldehyde (sinapaldehyde) in acetone at room temperature affords phosphonium zwitterions of the type R 3P +CH(4-O ?-Ar)CH 2CHO; other phosphines [R = Et, n-Bu, (CH 2) 2CN, and p-Tol] do not react under the same conditions. In alcohols R??OH(D) [R?? = CD 3, Et, (CD 3) 2CD, s-Bu, HOCH 2CH 2], the above phosphines (except the cyano-derivative) and those where R = i-Pr, Cy, Me 2Ph, MePh 2 do react within an equilibrium established between the reactants and the zwitterion-hemiacetal products R 3P +CH(4-O ?-Ar)CH 2CH(OH)(OR??) that are formed as a mixture of two diastereomers. The nature of the phosphine and the alcohol affects the equilibrium and the diastereomeric ratio. 相似文献
9.
Reaction of Na[AuCl 4] with 2-vinylpyridine (vinpy) and 2-ethylpyridine (etpy) affords the N-bonded adducts Au(Rpy)Cl 3 (R = CH 2CH, vinpy; CH 3CH 2, etpy). Cationic adducts, [Au(vinpy) 2Cl][X] 2 (X = BF 4, PF 6) and [Au(etpy) 2Cl 2][BF 4], were also obtained by reaction of Au(Rpy)Cl 3 with Rpy (1:1) and excess NaBF 4 or KPF 6. Thermal activation of Au(vinpy)Cl 3 in water gives the five-membered cycloaurated derivative [Au( k2- C,N-CH 2CH(Cl)-C 5H 4N)Cl 2] formally resulting through a trans nucleophilic addition of a chloride onto the CC bond. No cyclometallated derivatives are obtained by reactions of Au(etpy)Cl 3. An X-ray crystal structure determination on the PPh 3 derivative [Au( k2- C,N-CH 2CH(Cl)-C 5H 4N)(PPh 3)Cl][PF 6] was carried out. 相似文献
10.
The reaction of Pt(PPh 3) 4 with CH 2Cl1 in benzene yields the cationic ylide complex -[Pt(PPh 3) 2(CH 2PPh 3)Cl]I in high yield. This complex has been converted to -[(PPh 3) 2(CH 2PPh 3)X]X (X Br or I) by reaction with LiBr or NaI. Reaction of -[Pt(PPH 3)I]I with iodine yields -[Pt(PPh 3) 2(CH 2PPh 3)I]I 3. Nmr data are given in support of the suggested structures. 相似文献
11.
The dithiocarbene complex W(CO) 5[C(SCH 3) 2 reacts with tertiary phosphines, PPh 2CH 3, PPh(CH 3) 2, P(C 2H 5) 3 and P(OCH 3) 3 to form the phosphorane complexes W(CO) 5[CH 3S) 2C-PR 3] and with HPPh 2 to form the phosphine complex W(CO) 5[PPh 2[CH(SCH 3) 2]. Kinetic studies of both types of reactions show that their rates are first order each in W(CO) 5[C(SCH 3) 2] and in the phosphorus ligand. A mechanism involving rate determining phosphorus attack at the carbene carbon followed by rapid rearrangement to the product is consistent with this rate law. Rate constants for the reactions increase with increasing nucleophilicities of the phosphines: P(OCH 3) 3 < PPh 2H < PPh 2C H3 ? PPh(CH 3) 2 < P(C 2H 5) 3. The Δ H values decrease (P(OCH 3) 3 > PPh 2H > PPh 2(CH 3) > PPh(CH 3) 2 > P(C 2H 5) 3) as the nucleophilicities of the phosphines increase. The Δ S values (≈-30 e.u.) remain essentially constant for all the reactions. The cyclic dithiorcarbenes W(CO) 5[CS(CH 2) nS], where n- 3 or 4, react with PPh 2(CH 3) to form the cyclic phosphorane complexes, W(CO) 5[S(CH 2) nSC-PPh 2(CH 3)]. The 6- and 7- membered cyclic dithiocarbenes also react with PPh 2H to form the phosphine complexes, W(CO) 5 {PPh 2- [CS(CH 2) nS(H)]}. 相似文献
12.
Practical method of synthesis of the 1,4-dioxane derivative of the closo-dodecaborate anion was developed. The cleavage of the dioxonium ring in [B 12H 11O(CH 2CH 2) 2O] − with acetylenic alcohols gave rise to the preparation of closo-dodecaborate derivatives with terminal acetylene group. These compounds can be introduced into click reactions with phenylazide leading to the corresponding triazoles. The structures of (Bu 4N)[B 12H 11O(CH 2CH 2) 2O] and (Bu 4N) 2[B 12H 11(OCH 2CH 2) 2OCH 2CCH] · 0.5HOCH 2CCH were determined by single-crystal X-ray diffraction. 相似文献
13.
Reaction of the thiosemicarbazone ligands C 4H 4NC(H)=NN(H)C(S)NHR (R = Me, a ; Et, b ) with Li 2[PdCl 4] gave the dinuclear complexes [Pd{C 4H 4NC(H)=NNC(S)NHR}(μ‐Cl)] 2 (R = Me, 1a ; Et, 1b ) with a central Pd 2Cl 2 core and with deprotonation of the thiosemicarbazones at the hydrazinic nitrogen atom. Treatment of 1a and 1b with triphenylphosphine gave the mononuclear compounds [Pd{C 4H 4C(H)=NNC(S)NHR}(Cl)(PPh 3)] (R = Me, 2a ; Et, 2b ), whereas reaction of 1a and 1b with tertiary diphosphines gave mono‐ and dinuclear compounds, as appropriate, with the corresponding diphosphine acting as a monodentate ( 6b ), chelating ( 3a ) and bridging ligand ( 4a, 5a , 4b, 5b ). Treatment of 1a and 1b with (Ph 2PCH 2CH 2PPh 2)W(CO) 5 gave the new heterobimetallic complexes 7a and 7b . The crystal structures of complexes 3a and 4a are described. 相似文献
14.
A semiempirical MNDO method was used in calculations on monosubstituted neutral and cationic compounds of the [CH 3? CO? R] type with a wide range of substituents (R = H, F, Cl, CH 3, NH 2, OH, OCH 3, NHCH 3, CH?CH 2). The results obtained are interpreted with respect to the effect of the individual substituents on the geometry and electron distribution in the systems studied and allow the conclusion that the ratios of partial charges in the individual substructures in a radical cation correspond to those of the respective peak intensities in the mass spectrum. 相似文献
15.
The reactions of 1 mol equiv. each of [Ru(PPh 3) 3Cl 2] and N-(acetyl)- N′-(5- R-salicylidene)hydrazines (H 2ahsR, R = H, OCH 3, Cl, Br and NO 2) in alcoholic media afford simultaneously two types of complexes having the general formulae [Ru(HahsR)(PPh 3) 2Cl 2] and [Ru(ahsR)(PPh 3) 2Cl]. The complexes have been characterized by elemental analysis, magnetic, spectroscopic and electrochemical measurements. Molecular structures of [Ru(HahsH)(PPh 3) 2Cl 2] and [Ru(ahsH)(PPh 3) 2Cl] have been confirmed by X-ray crystallography. In both species, the PPh 3 ligands are trans to each other. The bidentate HahsH − coordinates to the metal ion via the O atom of the deprotonated amide and the imine–N atom in [Ru(HahsH)(PPh 3) 2Cl 2]. In HahsH −, the phenolic OH is involved in a strong intramolecular hydrogen bond with the uncoordinated amide N atom forming a seven-membered ring. In [Ru(ahsH)(PPh 3) 2Cl], the tridentate ahsH 2− binds to the metal ion via the deprotonated amide O, the imine N and the phenolate O atoms. In the electronic spectra, the green [Ru(HahsR)(PPh 3) 2Cl 2] and brown [Ru(ahsR)(PPh 3) 2Cl] complexes display several absorptions in the ranges 385–283 and 457–269 nm, respectively. Both complexes are low-spin and display rhombic EPR spectra in frozen solutions. Both types of complexes are redox active and display a quasi-reversible ruthenium(III) to ruthenium(II) reduction which is sensitive to the polar effect of the substituent on the chelating ligand. The reduction potentials are in the ranges −0.21 to −0.12 and −0.42 to −0.21 V (versus Ag/AgCl) for [Ru(HahsR)(PPh 3) 2Cl 2] and [Ru(ahsR)(PPh 3) 2Cl], respectively. 相似文献
16.
The dinuclear [NbCl n(OR) (5‐n)] 2 ( n = 4, R = Et, 1 ; n = 4, R = CH 2Ph, 2 ; n = 3, R = Et, 3 ; n = 2, R = Et, 4 ; n = 2, R = , 5 ), and [Nb(OEt) 5] 2, 6 , and the mononuclear niobium compounds NbCl 4[κ 2? OCH 2CH(R′)OR] ( R = Me, R′ = H, 7 ; R = Et, R′ = H, 8 ; R = CH 2Cl, R′ = H, 9 ; R = CH 2CH 2OMe, R′ = H, 10 ; R = R′ = Me, 11 ), NbBr 4[κ 2? OCH 2CH 2OMe], 12 , and NbCl 3(κ 2? OCH 2CH 2OMe)(κ 1? OCH 2CH 2OMe), 13 , were tested in ethylene polymerization. Optimized reaction conditions included the use of D‐MAO as co‐catalyst and chlorobenzene as solvent at 50 °C. Complex 7 , whose X‐Ray structure is described here for the first time, exhibited the highest activity ever reported for a niobium catalyst in alkene polymerization [151 kg polymer × mol Nb?1 × h?1 × bar ?1]. Compounds 1 , 3‐5 , 8 , 13 showed activities similar to that of 7 . Linear polyethylenes (characterized by FT‐IR, NMR, GPC, and DSC analyses) with a broad polydispersivity were obtained. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
17.
Reaction of [{Rh(μ-Cl)(CO) 2} 2] with PPh 2H in CO-saturated ethanol yields [Rh 3(μ-PPh 2) 3 (CO) 6 (PPh 2H)], a red trinuclear cluster of rhodium containing a near-planar six-membered Rh 3P 3 ring; this compound reversibly undergoes elimination of CO and PPh 2H to afford [Rh 3(μ-PPh 2) 3(CO) 5]. 相似文献
18.
The reaction of (C 5Me 5) 2Th(CH 3) 2 with the phosphonium salts [CH 3PPh 3]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C 5Me 5) 2Th[CHPPh 3]X, rare terminal phosphorano‐stabilized carbenes with thorium. These complexes feature the shortest thorium–carbon bonds (≈2.30 Å) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X=Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C 5Me 5) 2Th[κ 2‐(C,C′)‐(CH 2)(CH 2)PPh 2]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH 3PPh 3]X, X=Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene. 相似文献
19.
The reaction of (C 5Me 5) 2Th(CH 3) 2 with the phosphonium salts [CH 3PPh 3]X (X=Cl, Br, I) was investigated. When X=Br and I, two equivalents of methane are liberated to afford (C 5Me 5) 2Th[CHPPh 3]X, rare terminal phosphorano‐stabilized carbenes with thorium. These complexes feature the shortest thorium–carbon bonds (≈2.30 Å) reported to date, and electronic structure calculations show some degree of multiple bonding. However, when X=Cl, only one equivalent of methane is lost with concomitant formation of benzene from an unstable phosphorus(V) intermediate, yielding (C 5Me 5) 2Th[κ 2‐(C,C′)‐(CH 2)(CH 2)PPh 2]Cl. Density functional theory (DFT) investigations of the reaction energy profiles for [CH 3PPh 3]X, X=Cl and I showed that in the case of iodide, thermodynamics prevents the production of benzene and favors formation of the carbene. 相似文献
20.
1,2-electrophilic addition of TeCl 4 to the C=C bond of allylalcohol is observed, while with allylacetate, 1,3-addition occurs, due to migration of the acetate group. The allylalcohol adduct comprises two different kinds of molecules in the solid state, Cl 3Te[CH 2CH(Cl)CH 2OH→] and Cl 2Te[CH 2CH(Cl)CH 2CH-], with dative Te←O and covalent Te-O bonds, five-membered ring structures and Cl-Te?Cl and O-H?O bridges linking the different molecules. In the allylacetate adduct, Cl 3Te[CH 2CH(CH 2Cl)OC(CH 3)=O→], a six-membered ring is formed via an intramolecular dative Te←O interaction, the molecules being linked via C-Cl?Te bridges. Multinuclear NMR spectroscopy and 1H- 1H-NOESY combined with ab initio (MP2/LANL2DZP) geometry optimisation show the geometry of the ring structures in solution to be similar to those in the solid state. 相似文献
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