Nickel acetylacetonate

The reaction of a mixture of 1,5,9-cyclododecatriene (CDT), nickel acetylacetonate [3264-82-2], and diethylethoxyalurninum in ether gives red, air-sensitive, needle crystals of (CDT)Ni [12126-69-1] (66). Crystallographic studies indicate that the nickel atom is located in the center of the 12-membered ring of (CDT)Ni (104). The latter reacts readily with 1,5-cyclooctadiene (COD) to yield bis(COD) nickel [1295-35-8] which has yellow crystals and is fairly air stable, mp 142°C (dec) (20). Bis(COD)nickel also can be prepared by the reaction of 1,5-COD, triethylaluminum, and nickel acetylacetonate. 

The reaction of 3-amino-4-cyanofurazan with (3-dicarbonyl compounds in the presence of catalytic amounts of nickel acetylacetonate (Ni(acac)2) gave labile enamines that on treatment with acetic acid afforded fused pyridines of type 100 in 80-95% total yields (Scheme 51) (94MC57). Eurther syntheses of furazano-pyridines can be found in the review by Sheremetev (99RCR137, 99UK154). 

Combination of nickel bromide (or nickel acetylacetonate) and A. A -dibutylnorephcdrinc catalyzed the enantioselective conjugate addition of dialkylzincs to a./Tunsaturated ketones to afford optically active //-substituted ketones in up to ca. 50% ee53. Use of the nickel(II) bipyridyl-chiral ligand complex in acetonitrile/toluenc as an in situ prepared catalyst system afforded the //-substituted ketones 2, from aryl-substituted enones 1, in up to 90% ee54. 

The liquid-phase reduction method was applied to the preparation of the supported catalyst [27]. Virtually, Muramatsu et al. reported the controlled formation of ultrafine Ni particles on hematite particles with different shapes. The Ni particles were selectively deposited on these hematite particles by the liquid-phase reduction with NaBFl4. For the concrete manner, see the following process. Nickel acetylacetonate (Ni(AA)2) and zinc acetylacetonate (Zn(AA)2) were codissolved in 40 ml of 2-propanol with a Zn/Ni ratio of 0-1.0, where the concentration of Ni was 5.0 X lO mol/dm. 0.125 g of Ti02... 

Nickel acetylacetonate, Ni(acac)2, in the presence of a styrene derivative promotes coupling of primary alkyl iodides with organozinc reagents. The added styrene serves to stabilize the active catalytic species, and of the derivatives examined, m-trifluoromethylstyrene was the best.274... 

Under an atmosphere of argon, 50 mL of dry tetrahydrofuran (Note 2) and 23.6 mL (0.16 mol) of freshly distilled 1-octyne (Note 3) are added. The ice/water cooling bath is used to keep the temperature between 15°C and 25°C during the addition. Stirring is continued in the ice bath for 2 hr to control a mildly exothermic reaction then the flask is wrapped in aluminum foil and stirred overnight at room temperature (elapsed time is 18 hr). At this point, 10.9 mL (0.130 mol) of freshly distilled 2-cydopentenone (Note 3) is added and the reaction mixture is chilled in an ice bath for 10 min. To the cooled reaction mixture a total of 3.34 g (0.0130 mol) of vacuum-sublimed (at 180°C), powdered, solid nickel acetylacetonate (Notes 3,4) is added in three portions at 10-min intervals, keeping the temperature of the reaction mixture below 50 C (Notes 5,6). 

Octyne, cyclopentenone, and nickel acetylacetonate were purchased from the Aldrich Chemical Company, Inc. The checkers recrystallized the latter compound from anhydrous methanol followed by azeotropic drying with hot toluene. 

The checkers observed a significant induction period prior to onset of the exothermic reaction. Care must be taken to avoid addition of the nickel acetylacetonate too rapidly initially or temperature control becomes difficult. 

Ligand-free catalysts have been prepared from the following types of nickel(II) compounds nickel salts of long-chain aliphatic or aromatic carboxylic acids (10, 11) or of sulfonic acids (11), nickel enolates of /3-diketones (11) [e.g., nickel acetylacetonate (4, 12)] or their imino derivatives (11, 13), nickel phenolates (11), dithiocarbamates (14), and mer-captides (15). 

Nickel-based Ziegler catalysts can be prepared using halogen-free or-ganoaluminum compounds of low Lewis acidity, e.g., dialkylaluminum alkoxides. However, the catalytic properties of these systems differ remarkably from those described above. The nickel components in such a case may be nickel acetylacetonate, or the nickel enolates of various other /3-dicarbonyl compounds (44, 45), in particular such halogenated /3-dicarbonyl compounds as hexafluoroacetylacetone (44, 46). 

Examples of w-allylnickel-X compounds (X = anionic ligand) other than 77-allylnickel halides which have been used in combination with (alkyl)aluminum halides as olefin oligomerization catalysts are 7r-allyl-nickel acetylacetonate (11) (Section III), 7r-allylnickel aziridide (4, 56), and bis(7r-allyl)nickel (6) (59). In addition to ir-allylnickel halides, organo-nickel halides such as tritylnickel chloride (60, 61) and pentafluoro-phenylbis(triphenylphosphine)nickel bromide (62), or hydridonickel halides, e.g., trans-hydridobis(triisopropylphosphine)nickel chloride (12) (Section III), give active catalysts after activation with aluminum halides... 

Oxidative addition of the silyl species to nickel is followed by insertion of unsaturated substrates. Zero-valent nickel complexes, and complexes prepared by reducing nickel acetylacetonate with aluminum trialkyls or ethoxydialkyls, and in general Ziegler-Natta-type systems, are effective as catalysts (244, 260-262). Ni(CO)4 is specific for terminal attack of SiHCl3 on styrene (261). 

Nickel acetylacetonate Polyisoprene, Polyisoprene in hexane (2.5 wt.%) Uniroyal Inc. 16 (1976)... 

Nickel(II), concentration formation constant of chelates, 5 717t Nickel 200, in galvanic series, 7 805t Nickel acetate tetrahydrate, 17 117 Nickel acetylacetonate, 17 117 Nickel alloying process, 17 99-100 Nickel alloy plating, 9 821-822 Nickel alloys, 17 88, 95-104 13 512, 515-525... 

LDHs with Ni/Al molar ratio of 2.5 have been synthesized by a sol-gel method using nickel acetylacetonate and aluminium isopropylate as precursors. The sol-gel synthesized samples exhibited lower crystalhte dimensions and greater BET surface areas compared with coprecipitated samples prepared from an aqueous solution of nickel and aluminium nitrates [19,172]. 

In the calculations of the energy of hydration of metal complexes in the inner coordination sphere, one must consider hydrogen bond formation between the first-shell water molecules and those in bulk water, which leads to chains of hydrogen-bonded water molecules. Such hydrogen-bonded chains of ethanol molecules attached to the central metal ion have been found as a result of DFT B3LYP calculations on ethanol adducts to nickel acetylacetonate, where the calculated energy of hydrogen bonds correlated well with experimental data [90]. 

In relation to the consideration of the stereospecificity of coupling in Pm compounds, an observation of Kainosho<1969,95) seems especially important. Complexing the phosphorus atom by addition of a paramagnetic ion removes any stereospecific phosphorus couplings. In the phosphorinane 55a, 3J(POCHA) = 2-2 and aJ(POCHB) = 10-5 Hz but on increasing the concentration of nickel acetylacetonate in solution first... 

Nickel acetylacetonate is used as a catalyst in hydrogenation and other organic reactions. 

Nickel acetylacetonate is prepared by the reaction of acetylacetone with nickel chloride hexahydrate or nickel hydroxide, followed by crystaUization ... 

We have tested successfully a variant of this Mukaiyama procedure, that has been described in more detail subsequently (45-46). Our prior experience with nickel(II) catalysts impregnated on clays and nicknamed (47) "claynick" (48) and the convenience of a supported catalyst (49-50) made us opt for clay-impregnated nickel acetylacetonate as the catalyst. 

Ethyl acetoacetate reacts with benzoylacetonitrile in the presence of a catalytic amount of nickel acetylacetonate to give substituted 3-cyano[4,3-/)]pyridin-5-ones (Scheme 58) <1997RCB1041>. 

Nickel catalysts are also efficient in promoting the coupling of halopyridines and amines. In the presence of nickel acetylacetonate and Arduengo type carbene precursors chloropyridines were coupled with a series of amines to give the aminopyridines in high yield. 3-Chloropyridine, for example, reacted with A -mcthylanilinc to yield the anilinopyridine in 93% (7.75.), Of the carbene precursors tested l,3-bis(2 ,6 -... 

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