共查询到20条相似文献,搜索用时 31 毫秒
1.
Rafael Usón Luis A. Oro Miguel A. Ciriano Rafael Gonzalez 《Journal of organometallic chemistry》1981,205(2):259-271
The novel sixteen-electron complex [Ir(Oq)(COD)] (Oq = 8-oxyquinolate; COD = 1,5-cyclooctadiene) adds monodentate phosphines, phosphites or activated olefins irreversibly to give pentacoordinate iridium(I) complexes of the type [Ir(Oq)(COD)L] (L = PPh3, P(OPh)3, maleic anhydride or tetracyano-ethylene). Reaction of [Ir(Oq)(COD)] with some diphosphines leads to substitution products of the general formula [Ir(Oq)(diphos)] (diphos = 1,2-bis(diphenylphosphino)ethane or cis-1,2-bis(diphenylphosphino)ethylene). Carbon monoxide displaces the COD group from the complexes giving either [Ir(Oq)(CO)2] or [Ir(Oq)(CO)L], and the latter undergo oxidative addition reactions with SnCl4, Me3SiCl, Me3SnCl, MeI, allylbromide, PhCOCl, MeCOCl, Cl2, Br2, TlCl3 and HCl leading to novel iridium(III) complexes. 相似文献
2.
Gian Paolo Chiusoli Giuseppe Salerno Ugo Bersellini Franco Dallatomasina Severino Preseglio 《Transition Metal Chemistry》1978,3(1):174-176
Summary Allyl esters react selectively at room temperature with aromatic aldehydes and Nio complexes in alcoholic solvents to form aryl-substituted secondary alcohols. In tetrahydrofuran at 70°, ketones and aliphatic aldehydes react satisfactorily to give tertiary and secondary alcohols respectively. Ligands able to promote oxidative addition exert a favourable influence provided they do not complex to the exclusion of the substrate. 相似文献
3.
Amorphous nickel powder (Ni(0)) was utilised as a catalyst under mild, aqueous, basic conditions for enhancing the sodium borohydride-mediated reduction of C-N multiple bonds such as oximes, imines, hydrazones and nitriles to produce the corresponding amines in good to excellent yields. 相似文献
4.
Paulose TA Wu SC Olson JA Chau T Theaker N Hassler M Quail JW Foley SR 《Dalton transactions (Cambridge, England : 2003)》2012,41(1):251-260
Air and moisture stable homoleptic bis(diimidazolylidine)nickel(II) complexes, ([(diNHC)(2)Ni](2+)) 3a,b and their corresponding silver(I) 4a,b and palladium(II) 5a,b complexes were synthesized and characterized by NMR and single crystal X-ray analysis. The catalytic potential of complex 3a was assessed in Mizoroki-Heck and Suzuki-Miyaura coupling reactions. In the Suzuki-Miyaura coupling reaction, nickel precatalyst 3a was active for the coupling of aryl chlorides as well as aryl fluorides. The analogously synthesized Pd(II) complexes resulted in formation of (diNHC)PdCl(2) species which were not active for the coupling of aryl fluorides. For the Mizoroki-Heck reaction, it was found that aryl iodides could be activated in the absence of nickel or palladium precatalysts when using Na(2)CO(3) or NEt(3) as base while aryl iodides and aryl bromides could be activated in the Suzuki-Miyaura reaction sans precatalyst when K(3)PO(4) was used as base. 相似文献
5.
Odom AL 《Dalton transactions (Cambridge, England : 2003)》2005,(2):225-233
Titanium(IV) complexes with two basic dimethylamido ligands can be efficient catalysts for alkyne hydroamination by primary amines. Readily prepared pyrrolyl ligands have proven to be especially useful in generating active catalysts for hydroamination and hydrohydrazination. From these reactions, new methodologies for the synthesis of imines, hydrazones, alpha,beta-unsaturated imines, pyridines, indoles, and pyrroles have developed. In addition, a new reaction that is mechanistically related to hydroamination, alkyne iminoamination, has been discovered. Iminoamination, which is a multicomponent coupling between an amine, alkyne, and isonitrile, provides unsymmetrical alpha, beta-unsaturated beta-iminoamines in a single, titanium-catalyzed step. 相似文献
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7.
V. A. Milyukov A. V. Kataev E. Hey-Hawkins O. G. Sinyashin 《Russian Chemical Bulletin》2007,56(2):304-306
Reactions of trisodium heptaphosphide with half-sandwich cyclopropenyl complexes of nickel gave sodium 1,2-diphosphacyclopentadienide.
The influence of the ligand environment of the nickel atom on the formation of sodium 1,2-diphosphacyclopentadienide was studied.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 294–296, February, 2007. 相似文献
8.
The first asymmetric phase transfer catalyzed alkylation reaction of a range of carbon acids with N-sulfonyl aziridines is reported. When 10 mol % of a cinchona derived quaternary ammonium salt was employed as the catalyst under mildly basic conditions, N-o-(trifluoromethane)benzenesulfonyl aziridine was efficiently ring-opened to afford the amino ethylene products in consistently high yields and high enantioselectivities (up to 97% ee). By employing substituted aziridines in single enantiomeric form, the corresponding enantiopure alkylation products could be obtained with a range of pronucleophiles in high yields and moderate to high diastereoselectivities (up to 30:1 dr). 相似文献
9.
[reaction: see text]. Cycloaddition of aziridines with isocyanates proceeded smoothly in the presence of a nickel catalyst, and five iminooxazolidine derivatives were isolated in good yields. The best result was obtained when the reaction was carried out in the presence of NiI2, and a longer reaction time allowed the isomerization of the iminooxazolidine to the corresponding imidazolidinone derivatives. 相似文献
10.
Stephen C. Bergmeier Steven J. Katz Junfeng Huang Howard McPherson Patrick J. Donoghue Damon D. Reed 《Tetrahedron letters》2004,45(26):5011-5014
We have found that aziridines will react with a variety of π-nucleophiles in intramolecular cyclization reactions to produce nitrogen containing core structures found in a variety of bioactive molecules. These cyclizations are more general and facile than corresponding intermolecular reactions. We have examined the effects of ring size, π-nucleophile identity and substitution on this reaction. 相似文献
11.
Reactions of ethanolic disodium hexacyanobutenediide with the complexes L2MCl2 (M = Ni, L2 = 2,2′-bipyridyl, o-phenanthroline, or 1,2-bis(diphenylphosphino)-ethane; M = Pt, L = triphenylphosphine or triphenylarsine) give products of stoichiometry L2MC4(CN)6; the nature of these products is discussed. 相似文献
12.
Schmeier TJ Hazari N Incarvito CD Raskatov JA 《Chemical communications (Cambridge, England)》2011,47(6):1824-1826
The reactions of PCP supported Ni hydride, methyl and allyl species with CO(2) to generate Ni carboxylates are described. Computational studies suggest that all three reactions follow different pathways. 相似文献
13.
A family of heteroleptic RuII coordination complexes containing substituted 1,10-phenanthroline (phen) ligands with extended conjugation was found to exhibit two simultaneously emissive excited states at room temperature in fluid solution. These systems demonstrate a breakdown of the standard nonradiative decay pathways that normally lead to a single, dominant, lowest energy emissive excited state in RuII complexes and most other chromophores. The structural requirements for dual emission were explored through the synthesis and characterization of isomeric systems. Two features were found to be primarily responsible for resolvable dual emission. Extended conjugation at the 4-position of the 1,10-phenanthroline ligand was identified as an essential feature, and asymmetry in the phenanthroline ligand substitutions appears to greatly facilitate the production of these two nonequilibrated emissive states. Additional complexes were studied which displayed "tunable" emissive characteristics for the two excited states as a function of covalent and noncovalent modification. 相似文献
14.
Santanu Bhattacharya Basudeb Saha Amitava Dutta Pradyot Banerjee 《Coordination chemistry reviews》1998,170(1):47-74
This review narrates the electron transfer reactions of various nickel(III) and nickel(IV) complexes reported during the period 1981 until today. The reactions have been categorized mainly with respect to the type of nickel complexes. The reactivity of nickel(III) complexes of macrocycles, 2,2′-bipyridyl and 1,10-phenanthroline, peptides and oxime–imine, and of nickel(IV) complexes derived from oxime–imine, oxime and miscellaneous ligands with various organic and inorganic electron donors have been included. Kinetic and mechanistic features associated with such interactions have been duly analyzed. The relevance of Marcus cross-relation equations in the delineation of the electron transfer paths has also been critically discussed. 相似文献
15.
Gang Zuo 《Tetrahedron letters》2008,49(48):6797-6799
Ni/NHC was found to catalyze the rearrangement of vinyl aziridines and aziridinylen-ynes under mild conditions. 相似文献
16.
The influence of different modes of preparation on the stoichiometry of thermal decomposition of isothiocyanatonickel(II) complexes with ammonia was studied. It was found that the complex Ni(NCS)2(NH3)4 (I) prepared by heterogeneous reaction undergoes decomposition in two steps (–2 NH3, –2 NH3), while for complex II, of the same composition but prepared by homogeneous reaction from solution, the decomposition proceeds in three steps (–1 NH3, –1 NH3, –2NH3). Electronic and infrared absorption spectra were used for the study of the spectral properties of the starting complex. It was found that the different stoichiometries of thermal decompositions of complexes I and II do not cause differences in the bonding strength of the ammonia molecules (chemical factor); this effect is rather brought about by physical factors such as different imperfections of the crystal lattice.
Zusammenfassung Der Einfluß der Herstellung auf die Stöchiometrie der thermischen Zersetzung von Amin-Komplexen des Isothiocyanatonickels wurde studiert. Der Zerfall des Komplexes Ni(NCS)2(NH3)4 (I), hergestellt durch heterogene Reaktion, verlief in zwei Etappen (–2 NH3, –2 NH3). Beim selben Komplex (II), hergestellt durch homogene Reaktion in Lösung, wurden jedoch drei Etappen beobachtet (–1 NH3, –1 NH3, –2 NH3). Die Eigenschaften des Ausgangsproduktes wurden durch Elektronen- und IR-Spektroskopie untersucht. Das unterschiedliche thermische Verhalten ist nicht auf eine verschiedene Bindungsstärke der NH3 Moleküle, sondern auf physikalische Ursachen, wie z. B. Unregelmässigkeiten im Kristallgitter zurückzuführen.
Résumé On a étudié l'influence des diverses méthodes de préparation sur la stoechiométrie de la réaction de décomposition thermique des complexes de l'isothiocyanate de nickel(II) avec l'ammoniac. On a établi que le complexe Ni(SCN)2(NH3)4, (I), préparé rar réaction hétérogène, subit une décomposition en deux étapes (–2NH3, –2NH3), tandis que le complexe (II), de même composition, mais préparé par réaction homogène, à partir de solutions, se décompose en trois étapes (–1NH3,–1NH3, –2NH3). Les propriétés spectrales du complexe initial ont été étudiées par absorption électronique et infrarouge. On a trouvé que les différences de stoechiométrie des réactions de décomposition thermique des complexes (I) et (II) n'apportaient pas de différences entre les énergies de liaison des molécules d'ammoniac (facteur chimique). C'est plutôt à des facteurs physiques, comme les différentes imperfections du réseau cristallin, que cet effet serait dû.
(II) . , Ni(NCS)2(NH3)4 (I), , (–2NH3,–2NH3). , II , , (–1 NH3,–1 NH3 –2NH3). . , I II ( ), , .相似文献
17.
K. B. Yatsimirskii L. P. Tikhonova L. N. Zakrevskaya Ya. D. Lampeka A. G. Kolchinskii 《Reaction Kinetics and Catalysis Letters》1982,21(3):381-386
Copper and nickel complexes with tetraazamacrocyclic ligands are shown to act as catalysts in Belousov-Zhabotinskii oscillating reactions. New oscillating reactions, viz. the oxidation of unsaturated macrocyclic complexes of copper and nickel by bromate-ions, have been discovered.
, -. : - .相似文献
18.
19.
A mild, metal-free, and environmently benign iodine-promoted regioselective C-C and C-N bonds formation of N-protected indole derivatives giving 2,3'-biindoles 2 and 4-(1H-indol-2-yl)morpholines 4 is successfully demonstrated. Various bioactive 2,3'-biindoles and 4-(1H-indol-2-yl)morpholines, bearing electron-rich to moderately electron-poor substituents, can be prepared in moderate to good yields. 相似文献