Nickel, tetrakis synthesis

Nickel, methyltetrakis(trimethylphosphine)-tetraphenylborate stereochemistry, 44 Nickel, tetracarbonyl-exchange reactions, 288 Nickel, tetrakis(dinitrogen)-synthesis... 

Although the copper mediated Ullmann reaction is a well known method for biaryl synthesis, drastic conditions in the range of 150-280 °C are required. Zerovalent nickel complexes such as bis(l,5-cyclooctadiene)nickel or tetrakis(triphenylphosphine)nickel have been shown to be acceptable coupling reagents under mild conditions however, the complexes are unstable and not easy to prepare. The method using activated metallic nickel eliminates most of these problems and provides an attractive alternative for carrying out aryl coupling reactions(36,38). 

Dialkylindolines and 1,3-dialkylindoles are formed in poor yield (<10%) from the reaction of ethyl- or phenymagnesium bromide with 2-chloro-N-methyl-N-allylaniline in the presence of catalytic quantities of (bistriphenylphosphine)nickel dichloride.72 In a modification of this procedure, the allyl derivatives can be converted by stoichiometric amounts of tetrakis(triphenylphosphine)nickel into 1,3-dialkylindoles in moderate yield72 (Scheme 43) an initial process of oxidative addition and ensuing cyclization of arylnickel intermediates is thought to occur. In contrast to the nickel system,72 it has proved possible to achieve the indole synthesis by means of catalytic quantities of palladium acetate.73 It is preferable to use... 

In our study of the fluorination of coordinated chlorophosphine ligands (23), we started out with tetrakis(trichlorophosphine)nickel-(0), which could previously be converted into tetrakis(trifluorophosphine)nickel-(0) by displacement of the coordinated phosphorus trichloride with excess phosphorus trifluoride in a sealed tube (32). The limitations of this method, requiring the use of phosphorus trifluoride, a low boiling gas, under pressure, and involving the mechanical separation of the fluorophosphine complex from phosphorus trichloride, are obvious, and the yield was low. A straightforward method for the synthesis of this interesting compound was found in the fluorination of the coordinated phosphorus trichloride with potassium fluorosulfinate ... 

Tetrakis[phosphorus(III) chloride] nickel has been prepared by the reaction of nickel carbonyl with phosphorus-(III) chloride at room temperature.1 The synthesis of this compound as described below is based on this method. 

Biphenyl bond formation has been achieved in the diiodobiaryl derivative 41 by an intramolecular aryl halide coupling reaction promoted by tetrakis(tri-phenylphosphine) nickel. This short and efficient route gave the dibenzazonine 42 in good yield (42) (Scheme 9). In a similar way, tetrasubstituted derivative 43 was successfully coupled with the more easily prepared tris(triphenylphos-phine)nickel, giving 44 in 62% yield. Subsequent debenzylation led to the most efficient synthesis of dibenzazonine 35a reported to date (43). 

In 1996, Naka et al. described the synthesis of silicon-carbon unsaturated compounds via a nickel-catalyzed reaction <1996OM1101>. 3,4-Benzo-l,l,2,2-tetraethyl-l,2-disilacyclobut-3-ene 106 with bis(trimethylsilyl)acety-lene 107 in presence of a catalytic amount of tetrakis(triethylphosphine)nickel(0) in a sealed glass tube at 150 °C for 24h gave 5,6-benzo-l,l,4,4-tetraethyl-2,3-bis(trimethylsilyl)-l,4-disilacyclohex-2,5-diene 108, 4,5-benzo-l,l,3,3-tetraethyl-2-[bis(trimethylsilyl)methylene]-l,3-disilacyclopent-4-ene 109, 5,5,6,6,1 l,12,12-octaethyl-5,6,ll,12-tet a-silanaphthacene 110, and l,l -bis(3,4-benzo-2,2,5,5-tetraethyl-2,5-disilacyclopent-3-enylidene) 110, in 10%, 21%, 41%, and 9% yields (Scheme 13). 

As previously mentioned in Section 4.20.9.6.1, Naka et al. described the synthesis of silicon-carbon unsaturated compounds via a nickel-catalyzed reaction <1996OM1101>. The reaction between 3,4-benzo-l,l,2,2-tetraethyl-l,2-disilacyclobut-3-ene 106 with bis(trimethylsilyl)acetylene 107 in presence of a catalytic amount of tetrakis(triethyl-phosphine)nickel(O) gave the four metallaheterocyles detailed in Scheme 13. 

Fig. 3 Common reactions and cross-couplings in oligofluorene synthesis shown for example structures, where PdCl2(dppf) is [l,l -bis(diphenylphospino)ferrocene] dichloropaUadium(II), Pd(PPh3)4 is tetrakis(triphenylphosphino)palladium(0), and Ni(COD) is bis(l,5-cyclooctadiene)nickel(0)... 

The classical methodology of the Ullmann biaryl synthesis was significantly improved by Semmelhack et al. using zero-valent nickel complexes [28]. Aryl iodides were coupled in high yield using bis(1,5-cyclooctadiene)nickel(0) as catalyst. Yields were further improved by the application of tetrakis(triphenylphosph-ine)nickel(0) [29] (Scheme 40). 

Dienes. The (E)-l-alkcnylzirconium compounds, obtained by hydrozirconation of 1-alkynes (6, 177-178), undergo cross coupling with alkenyl halides to form conjugated dienes (cf. the similar reaction of alkcnylalanes with alkenyl halides, 7, 95-96). In the present synthesis tetrakis(triphenylphosphine)-palladium (6, 571-573) can usually serve as catalyst. Nickel catalysts are less effective than Pd catalysts in this case. ... 

Carvalho de Medeiros, M.A., S. Cosnier, A. Deronzier, and J.-C. Moutet (1996). Synthesis and characterisation of a new series of nickel(II) m w-tetrakis-(polyfluorophenyl)porphyrins functionalized by pyrrole groups and their electropolymerized films. Inorg. Chem. 35, 2659-2664. 

Tetrakis (trifluorophosphine) nickel, Ni(PF3)4 and Pt(PF3)4 can be obtained by direct synthesis of the gas with metal powder at 100°C and 300 atm. The very stable nickel compound contains zero valent tetrahedral nickel since sufficient lone pairs are donated by the ligand PF3 groups to complete... 

D. Zhang, C. A. Tessier and W. J. Youngs, Synthesis of tris(2,5-dialkynylthieno)cyclotriynes, tris(4,5-dialkoxyphenyl)cyclotriynes and tetrakis(4,5-dialkoxyphenyl)cyclotetraynes with long-chain alkyl substituents and the nickel and cobalt complexes of lris[4,5-(didodecyloxy)phenyl]cyclotriyne, Chem. Mater., 11, 3050-3057 (1999). 

A review has appeared on the synthesis and reactivity of (sUylamino) and (silyl-anilino)phosphines. The S5mthesis, derivatisation and coordination behaviour of the morpholine (69) and piperazine (70) derivatives have been described. They are formed from the appropriate amine with diphenylchlorophosphine, and both react with sulfur or selenium to give the chalcogenide, whilst reaction of (69) with paraformaldehyde leads to insertion of methylene into the P N bond to give the phosphine oxide. The reaction between ethylenediamine and diphenylchlorophosphine can lead to the bis-, tris- and tetrakis(diphenylphosphino)ethylene-diamines, depending upon the stoichiometry. The first two are oxidised in situ whist the latter, (71), is stable. A nickel complex of (71) has been shown to be active as a catalyst for ethylene pol5nnerisation. ... 

In conclusion, oxidative addition of aryl halides to metallic nickel proceeded smoothly under mild conditions, and the corresponding biaryls were obtained in good yields. The present reaction is superior to the Ullmann synthesis in the scope of the reaction conditions [125] and to the coupling reaction of Grignard reagents catalyzed by transition metals [133]. Finally, because of the simple and easy procedure for the preparation of nickel powder, it is far more convenient to work with than zerovalent nickel complexes such as tetrakis(triphenylphosphine)nickel(0) or bis(l,5-cyclooc-tadiene)nickel(O) [128]. 

De Medeiros MAC, Cosnier S, Deronzier A, Moutet JC (1996) Synthesis and characterization of a new series of Nickel(II) meso-Tetrakis (polyfluorophenyl)potphyrins functionalized by pyrrole groups and their electropolymerized films. Inorg Chem 35 2659-2664... 

In an extension of these studies, a new synthesis of indole derivatives was reported (Mori and Ban, 1976a) from 2-chloro-N-methyl-lV-allylaniline (XLll) by refluxing in ether for several hours with tetrakis(triphenyl-phosphine)nickel [Ni(PPh3)4]. The latter was prepared in situ to prevent deallylation. After oxygen was bubbled through the solution to convert PPhs into O <— PPhs for easy handling, the 1,3-dimethyl indole (XLIII) was obtained in a yield of 45.6%. 

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