Nickel-catalyzed cross coupling

Carbon-carbon bond-forming reactions are one of the most basic, but important, transformations in organic chemistry. In addition to conventional organic reactions, the use of transition metal-catalyzed reactions to construct new carbon-carbon bonds has also been a topic of great interest. Such transformations to create chiral molecules enantioselectively is therefore very valuable. While various carbon-carbon bond-forming asymmetric catalyses have been described in the literature, this chapter focuses mainly on the asymmetric 1,4-addition reactions under copper or rhodium catalysis and on the asymmetric cross-coupling reactions catalyzed by nickel or palladium complexes. 

Negishi, E., Takahashi, T., Akiyoshi, K. Aspects of cross-coupling reactions catalyzed by palladium and nickel complexes. Chem. Ind. 1988, 33, 381-407. 

Bis(oxazoline)pyridine (Pybox) and terpyridine (terpy) belong to the family of tridentate ligands that are often excluded from the discussions on pincer chemistry. However, recent studies have shown that in some cases they are redox-active [52, 53] and exhibit properties closely resembling those of pincer ligands. Thus, cross-coupling reactions catalyzed by nickel complexes containing these ligands are also discussed in this chapter. 

E. Negishi, T. Takahashi, and K. Akiyoshi, in Catalysis of Organic Reactions, P. N. Rylander, H. Greenfield, and R. L. Augustine, Eds., Mercel Dekker, New York, 1988, 381-407. Aspects of Cross-Coupling Reactions Catalyzed by Palladium and Nickel Complexes. 

Nickel (II) Catalyzed Cross-Coupling with Grignard Reagents (Kumada Reaction) Pure AppJ. Chem. 1980, 52, 669 Bull Chern. Soc.Jpn. 1976, 49, 1958... 

Optically active amine-thioether ligands (492) have been investigated in nickel-catalyzed asymmetric cross-coupling reactions of Grigard reagents.1338... 

Activated aryl chlorides, which are close in reactivity to unactivated aryl bromides, underwent reaction with the original P(o-tol)3-ligated catalyst.58 Nickel complexes, which catalyze classic C—C bond-forming cross-couplings of aryl chlorides, 9-64 also catalyzed aminations of aryl chlorides under mild conditions.65,66 However, the nickel-catalyzed chemistry generally occurred with lower turnover numbers and with a narrower substrate scope than the most efficient palladium-catalyzed reactions. 

Scheme 6.44 Nickel-catalyzed cross-coupling of zirconocenes and aryl halides.

Cross-coupling reactions of vinyl zirconocenes of general structure 41, mainly using group 10 metal catalysts, can be smoothly effected to give a variety of vinyl selenide-con-taining materials, which are amenable to further elaboration through nickel-catalyzed... 

Intramolecular cross-coupling can also be carried out as illustrated in the ring closure of Eq. 6 catalyzed by a nickel complex (L = l,2-bis-(diisopropyl phosphino)benzene) [25] ... 

With palladium catalysts aromatic chlorides are rather unreactive, however, nickel is able to catalyze the reactions of these substrates, too. The water-soluble catalyst was generated in situ from the easily available [NiCl2(DPPE)] and an excess of TPPTS by reduction with Zn in mixtures of 1,4-dioxane and water. Although it had to be used in relatively large quantities (10 mol %), the resulting compound catalysed the cross-coupling... 

The Kumada cross-coupling reaction (also occasionally known as the Kharasch cross-coupling reaction) is a nickel- or palladium-catalyzed cross-coupling reaction of a Grignard reagent with an organic halide, triflate, etc. 

Other successful examples of catalysts containing NHC ligands are found in palladium- and nickel-catalyzed carbon-carbon bond formations. The catalyst development with these metals has focused in particular on Heck-type reactions, especially the Mizoroki-Heck reaction itself [Eq. (42)] and various cross coupling reactions [Eq. (43)], e.g., the Suzuki-Miyaura reaction ([M] = and the Kumada-Corriu reaction ([M] = MgBr). " Related reactions like the Sonogashira coupling [Eq. (44)]326-329 Buchwald-... 

In the late 1970s and early 1980s, Kumada described nickel-catalyzed asymmetric cross-coupling reactions of 1-arylethylmagnesium chlorides with vinyl bromide in... 

Figure 3.49. Chiral ligands that exhibit high enantioselectivity in the nickel-catalyzed Grignard cross-coupling reaction of vinyl bromide (or chloride) with 1-phenylethylmagne-sium chloride.

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