Nickel-phosphine complexes, catalysts

The reaction of propargyl alcohols, when mn using a nickel-phosphine complex catalyst at room temperature, affords linear products 31 as is well known for... 

Alkyl- and aryl-pyridazines can be prepared by cross-coupling reactions between chloropyridazines and Grignard reagents in the presence of nickel-phosphine complexes as catalysts. Dichloro[l,2-bis(diphenylphosphino)propane]nickel is used for alkylation and dichloro[l,2-bis(diphenylphosphino)ethane]nickel for arylation (78CPB2550). 3-Alkynyl-pyridazines and their A-oxides are prepared from 3-chloropyridazines and their A-oxides and alkynes using a Pd(PPh3)Cl2-Cu complex and triethylamine (78H(9)1397). 

In addition to the neutral nickel/phosphine complexes used in the Shell Higher Olefins Process (SHOP), cationic Ni-complexes such as [(mall)Ni(dppmo)][SbF6] (see Figure 5.2-7) have attracted some attention as highly selective and highly active catalysts for ethylene oligomerization to HAOs [106]. 

Layered inorganic solids have been used for site isolation, for example, nickel phosphine complexes confined within the interlayer spaces of sepiolite have been used as olefin hydrogenation catalysts [63], and similarly there has been the encapsulation of metal complexes into zirconium phosphates [64], The principal idea is illustrated in Figure 5.8. The metal complex can be encapsulated by covalent means (a) or by non-covalent interactions (b). 

The monomers dealt with can be polymerized by various mechanisms, not only by ROMP. For example, a rapid polymerization of norbornadiene occurs using a homogeneous catalytic system consisting of nickel acetylacetonate or a nickel-phosphine complex, such as nickel bis-(tri-n-butylphosphine) dichloride (NiCl2(TBP)2) or nickel bis-(tricyclohexylphosphine) dichloride (NiCl2(TBP)2). Nickel acetylacetonate as catalyst is known to initiate rather a classical vinyl polymerization (7). The classical vinyl polymerization... 

The arylation of activated alkenes with aryl halides in the presence of base was discovered by R. F. Heck in 1971 and is now one of the standard methods for C—C bond formation. The catalysts are mostly palladium or nickel phosphine complexes, which react via a succession of oxidative addition and insertion reactions, as shown in the following simplified cycle ... 

Because of an increasing demand for these products in the pharmaceutical industry, a number of companies have paid special interest to the synthesis of profenes [32] such as ibuprofen, naproxen, ketoprofen and others from 1-arylethanol derivatives. Catalysts used for this transformation are palladium-phosphine complexes in concentrated hydrochloric acid, and to a lesser extent nickel-phosphine complexes in the presence of alkyl iodides or rhodium salts (cf. Section 2.9). 

Numerous complexes of nickel(II) and nickel(O) catalyze the addition of the Si-H bond to olefins. Among such catalysts are nickel-phosphine complexes, e.g., Ni(PR3)2X2 (where X=C1, I, NO3 R=alkyl and aryl), Ni(PPh3)4, and Ni-(CO)2(PPh3)2, as well as bidentate complexes of NiCl2-(chelate) and Ni(acac)2L (I phosphine), and Ni(cod)2(Pr3)2 [1-5]. A characteristic feature of nickel-phosphine-catalyzed olefin hydrosilylation is side reactions such as H/Cl, redistribution at silicon and the formation of substantial amounts of internal adducts in addition to terminal ones [69]. Phosphine complexes of nickel(O) and nickel(II) are used as catalysts in the hydrosilylation of olefins with functional groups, e.g., vinyl acetate, acrylonitrile [1-4], alkynes [70], and butadiynes [71]. 

A remarkable example of the cooperation of different active sites in a polyfunctional catalyst is the one-step synthesis of 2-ethylhexanol, including a combined hydroformylation, aldol condensation, and hydrogenation process [17]. The catalyst in this case is a carbonyl-phosphine-rhodium complex immobilized on to polystyrene carrying amino groups close to the metal center. Another multistep catalytic process is the cyclooligomerization of butadiene combined with a subsequent hydroformylation or hydrogenation step [24, 25] using a styrene polymer on to which a rhodium-phosphine and a nickel-phosphine complex are anchored (cf Section 3.1.5). 

Gan L, Groy TL, Tarakeshwar P, Mazinani SKS, Shearer J, Mujica V, Jones AK (2015) A nickel phosphine complex as a fast and efficient hydrogen production catalyst. J Am Chem Soc 137(3) 1109-1115. doi 10.1021/ja509779q... 

Two reports have described the use of nickel-phosphine complexes as catalysts in the cross-coupling of Grignard reagents with aryl and vinyl halides. The reaction of benzal and other benzylic halides with lithium di-alkylcopper reagents has been explored as a potential route to quaternary carbon atoms preliminary results are not promising. ... 

Nickelocenes, reactions, review 27, 813 suppl. 29 Nickel phosphine complexes as catalysts 19, 778 suppl. 29 20, 531 suppl. 29 ... 

K. Tamao, Y. Kiso, K. Sumitani, M. Kumada, AUcyl group isomerization in cross-coupling reaction of secondary alkyl grignard-reagents with organic halides in presence of nickel-phosphine complexes as catalysts, J. Am. Chem. Soc. 1972, 94, 9268. 

Coordination-catalyzed ethylene oligomerization into n-a-olefins. The synthesis of homologous, even-numbered, linear a-olefins can also be performed by oligomerization of ethylene with the aid of homogeneous transition metal complex catalysts [26]. Such a soluble complex catalyst is formed by reaction of, say, a zero-valent nickel compound with a tertiary phosphine ligand. A typical Ni catalyst for the ethylene oligomerization is manufactured from cyclo-octadienyl nickel(O) and diphenylphosphinoacetic ester ... 

In a Kumada-Corriu reaction, an aryl halide is oxidatively coupled with a homogeneous nickel(ll)-phosphine catalyst [2], This species reacts with a Grignard reagent to give biaryl or alkylaryl compounds. Later, palladium-phosphine complexes were also successfully applied. By this means, stereospecific transformations were achieved. 

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