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Leonid N. Bochkarev Vladislav I. Scherbakov Irina P. Malysheva Galina V. Basova Natalia E. Stolyarova Irina K. Grigorieva Andrey L. Bochkarev Georgii K. Fukin Yurii A. Kurskii Gleb A. Abakumov 《Journal of organometallic chemistry》2006,691(5):983-986
The novel silicon-, germanium- and tin-containing imido alkyl complexes of tungsten of the type (ArN)2W(CH2EMe3)2 (; E = Si (1), Ge (2), Sn (3)) have been prepared by the reactions of (ArN)2WCl2(dme) (dme = 1,2-dimethoxyethane) with heteroelement-containing alkyllithium or Grignard reagents Me3ECH2Li (E = Si, Ge), Me3ECH2MgCl (E = Ge, Sn). The title compounds were isolated in high yields as crystalline solids and characterized by elemental analysis, IR, 1H, 13C, 29Si and 119Sn NMR spectroscopy and X-ray diffraction studies. The geometry of the W atoms in the compounds can be described as a distorted tetrahedron. 相似文献
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The phenylimidorhenium(V) complexes [Re(NPh)X3(PPh3)2] (X = Cl, Br) react with the N‐heterocyclic carbene (NHC) 1,3‐diethyl‐4,5‐dimethylimidazole‐2‐ylidene (LEt) under formation of the stable rhenium(V) complex cations [Re(NPh)X(LEt)4]2+ (X = Cl, Br), which can be isolated as their chloride or [PF6]? salts. The compounds are remarkably stable against air, moisture and ligand exchange. The hydroxo species [Re(NPh)(OH)(LEt)4]2+ is formed when moist solvents are used during the synthesis. The rhenium atoms in all three complexes are coordinated in a distorted octahedral fashion with the four NHC ligands in equatorial planes of the molecules. The Re–C(carbene) bond lengths between 2.171(8) and 2.221(3) Å indicate mainly σ‐bonding between the NHC ligand and the electron deficient d2 metal atoms. Attempts to prepare analogous phenylimido complexes from [Re(NPh)Cl3(PPh3)2] and 1,3‐diisopropyl‐4,5‐dimethylimidazole‐2‐ylidene (Li?Pr) led to a cleavage of the rhenium‐nitrogen multiple bond and the formation of the dioxo complex [ReO2(Li?Pr)4]+. 相似文献
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Reaction of MCl5 (M = Nb, Ta) with excess of tBuNH2 in the presence of pyridine leads to formation of mononuclear complexes [M(NtBu)(NHtBu)Cl2Py2],M = Nb ( 1 ), Ta ( 2 ). These new key compounds are characterized by 1H, 13C NMR spectroscopy, mass spectrometry and elemental analyses. A single crystal structure analysis of [Ta(NtBu)(NHtBu)Cl2Py2] ( 2 ) reveals, that surprisingly chloro and not pyridine ligands are trans to the strongest π donor ligands [NtBu]2? and [NHtBu]?. 相似文献
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Transition-metal-catalyzed direct C–H bond amination is an attractive strategy in preparation of nitrogen containing molecules which are common in naturally occurring and pharmaceutically important compounds. Comparing to the precious metals commonly used in this reaction, non-precious metals such as iron are abundant in earth, relatively low toxic, and more biocompatible, which meet the increasing demand for environmentally benign and sustainable chemical processes. In this review, we described the development in iron catalyzed C–H bond amination reactions from historical landmarks to recent achievements, and placed emphasis on their applications in organic synthesis, i.e. natural product synthesis and/or modification. 相似文献
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Synthesis of niobocene imido cations: X-ray crystal structure of [Nb(NBu)(η-C5H4SiMe3)2(CNBu)][BPh4]
Andrés Garcés Santiago Gómez-Ruiz Antonio Antiñolo Carmen López-Mardomingo Sanjiv Prashar 《Journal of organometallic chemistry》2006,691(17):3652-3658
The reduction of [Nb(NBut)(η5-C5H4SiMe3)2Cl] by sodium amalgam followed by oxidation by [Fe(η5-C5H5)2][BPh4] in the presence of CNBut gave [Nb(NBut)(η5-C5H4SiMe3)2(CNBut)][BPh4] (1). In a similar manner, [Nb(NPh)(η5-C5H4SiMe3)2(CNBut)][BPh4] (2), [Nb(NPh)(η5-C5H4SiMe3)2(CO)][BPh4] (3) and [Nb(NBut){Me2Si(η5-C5Me4)(η5-C5H4)}(CNBut)][BPh4] (4), were prepared. The reduction of [Nb(NBut){Me2Si(η5-C5H4)2}Cl] gave, depending on the experimental conditions, either the d1-d1 dimer [(Nb{Me2Si(η5-C5H4)2}(μ-NBut))2] (5) or the hydride derivative [Nb(NBut){Me2Si(η5-C5H4)2}H] (6). The reaction of 5 with I2 led to the formation of [Nb(NBut){Me2Si(η5-C5H4)2}I] (7). The molecular structure of 1 was determined by single-crystal X-ray diffraction studies. 相似文献
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U. Siemeling T. Türk U. Hammermeister 《Monatshefte für Chemie / Chemical Monthly》1995,126(6-7):725-732
Summary 2-(2-Nitrophenyl)-ethanol (2) was methylated with dimethyl sulfate to give 2-(2-methoxyethyl)-1-nitrobenzene (3a) which then was reduced with hydrazine hydrate in the presence ofRaney nickel to 2-(2-methoxyethyl)-aniline (1a). Compound1a can be transformed into the N-monosilylated derivative4 by lithiation withn-butyllithium and subsequent reaction with chlorotrimethylsilane. Reaction of2 withp-toluenesulfonyl chloride yields 2-(2-nitrophenyl)-ethylp-toluenesulfonate (5), which reacts with sodium thiomethoxide to give 2-(2-nitrophenyl)-ethylp-toluenesulfonate (5), which reacts with sodium thiomethoxide to give 2-(2-thiomethoxyethyl)-1-nitrobenzene (3b).3b was reduced with hydrazine hydrate in the presence ofRaney nickel to yield 2-(2-thiomethoxyethyl)-aniline (1b). Ethyl (2-nitrophenyl)-acetate (6) could be dimethylated with methyl iodide in the presence of potassiumtert-butoxide and 18-crown-6 to give ethyl 2-methyl-2-(2-nitrophenyl)-propionate (7). Reduction of7 with lithium borohydride yields 2,3-dihydro-3,3-dimethyl-1H-indole (9) and 2-[(1-hydroxy-2-methyl)-2-propyl]-aniline (10).
Synthese von 2-(2-Methoxyethyl)- und 2-(2-Thiomethoxyethyl)-anilin und verwandten Verbindungen
Zusammenfassung 2-(2-Nitrophenyl)-ethanol (2) wurde mit Dimethylsulfat zu 2-(2-Methoxyethyl)-1-nitrobenzol (3a) methyliert, das sich mit Hydrazinhydrat in Gegenwart vonRaney-Nickel zu 2-(2-Methoxyethyl)-anilin (1a) reduzieren läßt. Verbindung1a kann durch Metallierung mitn-Butyllithium und anschließende Reaktion mit Chlortrimethylsilan in dasN-monosilylierte Derivat4 umgewandelt werden. Reaktion von2 mitp-Toluolsulfonylchlorid ergab 2-(2-Nitrophenyl)-ethyl-p-Toluolsulfonat (5), das mit Natriumthiomethanolat zu 1-Nitro-2-(2-thiomethoxyethyl)-benzol (3b) reagiert.3b wurde mit Hydrazinhydrat in Gegenwart vonRaney-Nickel zu 2-(2-Thiomethoxyethyl)-anilin (1b) reduziert. Ethyl-2-(nitrophenyl)-acetat (6) kann mit Methyliodid in Gegenwart von Kalium-tert-butoxid und 18-Krone-6 zu Ethyl-2-methyl-2-(2-nitrophenyl)-propionat (7) dimethyliert werden. Reduktion von7 mit Lithiumborhydrid lieferte 2,3-Dihydro-3,3-dimethyl-1H-indol (9) und 2-[(1-Hydroxy-2-methyl)-2-propyl]-anilin (10).相似文献
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A.Charis R. Croft 《Journal of organometallic chemistry》2003,683(1):120-130
Chloride ligand substitution reactions of tert-butyl- and arylimido-titanium complexes supported by the pendant arm functionalised N-trimethylsilyl benzamidinate ligand Me3SiNC(Ph)NCH2CH2CH2NMe2 are described. Reaction of previously-described [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}Cl] (1) with PhLi afforded thermally sensitive [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}Ph] (2). The corresponding reaction of 1 with MeLi afforded [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}Me] (3) detected by 1H-NMR spectroscopy but this compound could not be isolated. Reaction of 1 with LiCH2SiMe3 gave a complex mixture, but with LiN(SiMe3)2 and LiO-2,6-C6H3Me2 the compounds [Ti(NtBu){Me3SiNC(Ph)NCH2CH2CH2NMe2}X] (X=N(SiMe3)2 (4) or O-2,6-C6H3Me2 (5)) were isolated. The X-ray structure of 5 was determined. Reaction of the homologous compound [Ti(NtBu){Me3SiNC(Ph)NCH2CH2NMe2}Cl] (6) (containing a 2-carbon atom chain in the pendant arm) with MeLi or PhLi were unsuccessful although the aryloxide compound [Ti(NtBu){Me3SiNC(Ph)NCH2CH2NMe2}(O-2,6-C6H3Me2)] (7) could be isolated from the reaction of 6 with LiO-2,6-C6H3Me2. Reaction of the 3-carbon pendant arm arylimido compound [Ti(N-2,6-C6H3Me2){Me3SiNC(Ph)NCH2CH2CH2NMe2}Cl] (8) with MeLi afforded thermally sensitive [Ti(N-2,6-C6H3Me2){Me3SiNC(Ph)NCH2CH2CH2NMe2}Me] (9), and although the analogous phenyl homologue was elusive, the aryloxide derivative [Ti(N-2,6-C6H3Me2){Me3SiNC(Ph)NCH2CH2CH2NMe2}(O-2,6-C6H3Me2)] (10) was successfully isolated and structurally characterised. Comparison of the X-ray structures of 5 and 10 show unexpectedly large differences between the TiNR and TiOAr bond lengths in the two compounds. 相似文献
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Against the background of the (propene)Mo(=O)(=NH) and (allyl)Mo(=O)(=NH) surface species suggested as intermediates of the SOHIO process the potential of H2N–C6H4–CH2– CH=CH–CH3, ( I ), for the introduction of chelating imido/olefin or imido/allyl ligands at highvalent Mo centres was tested. Reaction of I with Na2[MoO4] and trimethylchlorosilane yielded [Cl2Mo(=N–C6H4–CH2–CH=CH–CH3)2(dme)] ( 1 ), containing pendant olefinic arms. All attempts to introduce the olefin into the coordination sphere of the Mo centre failed. The same observation was made with [Cl2Mo(=O)(=N–C6H4–CH2–CH=CH–CH3)(dme)] ( 2 ), synthesised via a commutation reaction from 1 and[(dme)Cl2Mo(=O)2]. Reaction of three equivalents of I with [CpMoCl4′] yields [CpCl2Mo(=N–C6H4–CH2–CH=CH–CH3)], ( 3 ), again with a pendant olefin arm; the products of experiments aiming at coordinating it to the Mo atom eluded isolation. I thus does not seem suitable for the synthesis of complexes with imido/olefin or imido/allyl ligands. However, products 1 – 3 , (two of which ( 1 , 3 ) were also characterised by single crystal X‐ray diffraction) are nevertheless interesting, e.g., with respect to the grafting of molybdenum complexes on the surfaces of solid supports to obtain heterogeneous oxidation catalysts. 相似文献