Halides nickel

Nickel halide complexes with amines give mixtures of linear polymer and cychc trimers (30). Nickel chelates give up to 40% of linear polymer (31). When heated with ammonia over cadmium calcium phosphate catalysts, propargyl alcohol gives a mixture of pyridines (32). 

There are few reports of oxidative addition to zerovalent transition metals under mild conditions three reports involving group 10 elements have appeared. Fischer and Burger reported the preparation of aTT -allylpalladium complex by the reaction of palladium sponge with allyl bromide(63). The Grignard-type addition of allyl halides to aldehydes has been carried out by reacting allylic halides with cobalt or nickel metal prepared by reduction of cobalt or nickel halides with manganese/iron alloy-thiourea(64). 

The activated nickel powder is easily prepared by stirring a 1 2.3 mixture of NiL and lithium metal under argon with a catalytic amount of naphthalene (1(7 mole % based on nickel halide) at room temperature for 12 h in DME. The resulting black slurry slowly settles after stirring is stopped and the solvent can be removed via cannula if desired. Washing with fresh DME will remove the naphthalene as well as most of the lithium salts. For most of the nickel chemistry described below, these substances did not affect the reactions and hence they were not removed. The activated nickel slurries were found to undergo oxidative addition with a wide variety of aryl, vinyl, and many alkyl carbon halogen bonds. 

The present reaction may be reasonably explained by the smooth oxidative addition of aryl halides to metallic nickel to give aryl nickel halides, followed by disproportionation to bisarylnickels, which upon reductive elimination afford the dehalogenative coupled products. Providing strong support for this mechanism, the intermediates, arylnickel halide and bisarylnickel (Ar=C F ), were isolated as the phosphine complexes. 

The development of the Grignard-type addition to carbonyl compounds mediated by transition metals would be of interest as the compatibility with a variety of functionality would be expected under the reaction conditions employed. One example has been reported on the addition of allyl halides to aldehydes in the presence of cobalt or nickel metal however, yields were low (up to 22%). Benzylic nickel halides prepared in situ by the oxidative addition of benzyl halides to metallic nickel were found to add to benzil and give the corresponding 3-hydroxyketones in high yields(46). The reaction appears to be quite general and will tolerate a wide range of functionality. 

Alkyl oxalyl chlorides, reactions, 228 Aryl nickel halides, formation, 227 3-Arylpropanenitriles, preparation, 229... 

The primary (7, 47) and most commonly used organonickel compounds have been the dimeric 7r-allyl- (or substituted Tr-allyl-) nickel halides (1) (Scheme 1) or their monophosphine adducts (2) in the presence of Lewis acids such as aluminum halides or alkylaluminum halides (4, 48-53). The... 

It is generally assumed that the Lewis acid in 3 decreases the charge on the metal, i.e., increases its electrophilicity. The removal of charge from the nickel allows additional electron donors to coordinate to the nickel atom, and reaction with, for example, 2 moles of carbon monoxide or 1 mole of 1,5-cyclooctadiene (COD) gives the insoluble, catalytically inactive and presumably ionic complexes 7 and 8. In contrast, 7r-allyl-nickel halides (1) add only 1 mole of carbon monoxide while they do not react with COD (52). 

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... 

Nickel halides and nickel complexes resulting from oxidative addition can also give rise to subsequent replacement and insertion reactions. Replacement reactions have been described mainly with arylnickel halide complexes (examples 23, 29, and 31, Table III). Carbanionic species replace halide ions and can undergo coupling or insertion reactions. An example of application of a carbanionic reaction to the synthesis of a natural product is the coupling step between an aromatic iodo-derivative and an active methylene group to form cephalotaxinone (example 23, Table III). 

I, Table X) requires tertiary phosphine-nickel halide or tertiary phosphine-nickel carbonyl complexes at 140-170°C. This implies oxidative addition of aromatic halides to nickel, replacement of the halide with amines, and reductive elimination. 

Anhydrous nickel chloride, 17 110 Anhydrous nickel fluoride, 17 110 Anhydrous nickel halides, properties of, 17 HOt... 

Nickel formate dihydrate, 77 117 Nickel halides, 77 109-110 Nickel-hydride battery modules, 7 7 95... 

Methanol can be hydroformylated with syngas (CO and H2) in the presence of a copper or nickel halide catalyst to give acetaldehyde. Reaction conditions are 350-400°F and 4000-6000 psi. 

The formation of a deep blue color in a solution of a nickel halide in various organic solvents is quite common, but, in the absence of other... 

Ammino-derivatives of Nickel Salts—Derivatives of Nickel Halides, Nitrate, Nitrite, Sulphate. 

The nickel halide complexes of Schiff bases (113) and (114) obtained from benzaldehyde and a number of diamines have the formula NiX2L (X = Cl, Br, I) with pseudotetrahedral structure in the solid state and in solution as well.954... 

A number of nickel(II) alkoxyhalides of the types Ni(OMe)X, Ni3(OMe)5X, Ni3(OMe)4X2 (X = halides) and Ni(OMe)Cl MeOH were prepared by reacting either NaOMe or LiOMe with anhydrous nickel halides in methanol.1495 The structures of these complexes which exhibit ferromagnetic behaviour are thought to involve cubane-type clusters. Other complexes with miscellaneous ligands containing the OH function are collected in Table 76. 

The reaction of trimethyl phosphate, (MeO)3PO, with NiBr2 results in the neutral bis-dimethoxyphosphato complex by elimination of one methyl group from the neutral phosphoric esters (equation 185).1708 But when nickel halides are reacted at higher temperatures with the neutral diisopropylmethylphosphonate, an alkyl elimination and a phosphato condensation occur (equation 186).1709... 

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