Nickel complexes alcohols

Shell Higher Olefin Process) plant (16,17). C -C alcohols are also produced by this process. Ethylene is first oligomerized to linear, even carbon—number alpha olefins using a nickel complex catalyst. After separation of portions of the a-olefins for sale, others, particularly C g and higher, are catalyticaHy isomerized to internal olefins, which are then disproportionated over a catalyst to a broad mixture of linear internal olefins. The desired fraction is... 

A proline derived chiral nickel complex 1 may be used instead of oe,/J-unsaturated esters of lactones modified with a chiral alcohol as the Michael acceptor. The a,(9-unsaturated acid moiety in 1 reacts with various enolates to afford complexes 2 with diastereomcric ratios of 85 15 to 95 5. Hydrolysis of the imine moiety yields the optically active /(-substituted r-alanines. A typical example is shown296. 

These telomerization reactions of butadiene with nucleophiles are also catalyzed by nickel complexes. For example, amines (18-23), active methylene compounds (23, 24), alcohols (25, 26), and phenol (27) react with butadiene. However, the selectivity and catalytic activity of nickel catalysts are lower than those of palladium catalysts. In addition, a mixture of monomeric and dimeric telomers is usually formed with nickel catalysts ... 

Reactions of alcohols, ethers, and aliphatic halides with carbon monoxide were described as far back as 1948-1953 (173, 195). High pressure and temperature were required, however, for these processes. The use of alkaline media allowed carbonylation of alkyl iodides under mild conditions (example 22, Table VII). More recently, carbonylation of alkyl-nickel complexes was reported (example 26, Table VII). 

Allylation of amines with allyiic alcohols in the presence of reducible nickel complexes easily occurs at 80°C (example 4, Table X). 

Nickel complexes are also active catalyst for the isomerization of allylic alcohols. Ni(dppb)2, prepared by mixing Ni(cod)2/2dppb (2equiv.), catalyzed the isomerization of geraniol to citronellal in the presence of CF3C02H (4equiv.) in toluene at 80 °C (Equation (10)).34... 

P.Y.153 is a nickel complex which was introduced to the market in the late 1960s. It produces slightly dull reddish shades of yellow. Although not fast to acids, the pigment may safely be exposed to alkali. It is fast to mineral spirits and alcohols, but only moderately so to aromatic solvents, such as xylene, and to esters, such as ethyl acetate. 

The regioselectivity is maintained with mono- and even disubstituted propargylic chlorides (Table 9.33) [56], The copper complex affords allenylcarbinols (A) and the nickel complex favors homopropargylic alcohols (B). In the latter case, the syn adducts are predominant, suggestive of an acylic transition state. 

Thioethers (sulfides) can be prepared by treatment of alkyl halides with salts of thiols (thiolate ions).7S2 R may be alkyl or aryl. As in 0-35, RX cannot be a tertiary halide, and sulfuric and sulfonic esters can be used instead of halides. As in the Williamson reaction (0-12), yields are improved by phase-transfer catalysis.753 Instead of RS ions, thiols themselves can be used, if the reaction is run in benzene in the presence of DBU (p. 1023).754 Neopentyl bromide was converted to Me3CCH2SPh in good yield by treatment with PhS in liquid NH3 at -33°C under the influence of light.755 This probably takes place by an SrnI mechanism (see p. 648). Vinylic sulfides can be prepared by treating vinylic bromides with PhS in the presence of a nickel complex,756 and with R3SnPh in the presence of Pd(PPh3)4.757 R can be tertiary if an alcohol is the substrate, e.g,758... 

Copper and nickel complexes of the tridentate l-(2-carboxyphenyl)-3,5-diphenyl- (169 X = C02 R = R = Ph) and 1-(2-hydroxyphenyl)-3,5-diphenyl-(169 X = 0 R = R = Ph) formazans were prepared118 by the interaction of the formazan and the appropriate metal acetate in alcohol and were assigned the three-coordinate structures (170 X = O, C02 R = R = Ph M = Ni, Cu) since the diamagnetic nickel complexes were found to be unimolecular in benzene solution. Treatment of the nickel complex (170 X = O, R = R = Ph M = Ni) with pyridine gave a violet crystalline adduct which was assigned the four-coordinate structure (171 X = O R = R = Ph M = Ni). A product similar to the latter could not be obtained from the nickel complex of l-(2-carboxyphenyl)-3,5-diphenylformazan but nickel complexes of this type were obtained from both l-(2-hydroxyphenyl)- (169 X = O, R = CN R = Ph) and l-(2-carboxyphenyl)- (169 X = C02 R = CN R = Ph) 3-cyano-5-phenylformazans. In all three cases a considerable shade change occurred on going from the three-coordinate complex to the pyridine adduct. 

One of the most interesting alternatives to the Shirakawa catalyst has been the systems disclosed by Luttinger 22-23) and later elaborated by Lieser et al. 24). The tris(2-cyanoethyl)phosphine complex of nickel chloride reacts with sodium boro-hydride to produce a catalyst system capable of polymerizing acetylene in solutions in either alcohol or, quite remarkably, water. A more efficient catalyst is obtained by replacing the nickel complex with cobalt nitrate. Interest in Luttinger polyacetylene seems to have waned in the last few years. 

Oxygenation of RCHO to RCOOH.1 This oxidation can be effected by oxygen when catalyzed by nickel complexes such as bis(acetylacetonato)nickel, Ni(acac)2. However, the highest conversion and yields are obtained with the complex prepared from l,3-di(p-methoxyphenyl)-l,3-propanedionate, Ni(dmp)2. Ether or an alcohol... 

A useful spot test utilizes the fact that a suspension of red nickel dimethylglyoxime in water when treated with a neutral or acetic acid solution of a palladium salt yields the yellow palladium dimethylglyoxime, which is sparingly soluble in dilute acids. The test is best performed with dimethylglyoxime paper the latter is prepared as follows. Immerse drop-reaction paper in a 1 per cent alcoholic solution of dimethylglyoxime, dry, then immerse again in a solution of 05m nickel chloride rendered barely ammoniacal. The nickel complex precipitates wash thoroughly with water, immerse in alcohol and dry. 

The reaction gives good yields with primary, secondary, and tertiary alcohols, and with alkyl and arylhthium reagents. Allylic alcohols also couple with certain Grignard reagents in the presence of a nickel complex to give both normal products and the products of allylic rearrangement. 

Oguni has reported asymmetric amplification [12] ((-i-)-NLE) in an asymmetric carbonyl addition reaction of dialkylzinc reagents catalyzed by chiral ami-noalcohols such as l-piperidino-3,3-dimethyl-2-butanol (PDB) (Eq. (7.1)) [13]. Noyori et al. have reported a highly efficient aminoalcohol catalyst, 2S)-3-exo-(dimethylamino)isobomeol (DAIB) [14] and a beautiful investigation of asymmetric amplification in view of the stability and lower catalytic activity of the het-ero-chiral dimer of the zinc aminoalcohol catalyst than the homo-chiral dimer (Fig. 7-5). We have reported a positive non-linear effect in a carbonyl-ene reaction [15] with glyoxylate catalyzed by binaphthol (binol)-derived chiral titanium complex (Eq. (7.2)) [10]. Bolm has also reported (-i-)-NLE in the 1,4-addition reaction of dialkylzinc by the catalysis of nickel complex with pyridyl alcohols [16]. 

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