Nickel-catalyzed arylation

Fig. 11. Influence of the base on the Nickel catalyzed arylation of alcohols...

Fig. 16.11. Nickel-catalyzed arylation of Grignard compounds. The Grignard compound can be prepared via a substituent-directed peri-lithia-tion of a substituted naphthalene (see Section 5.3.1 for the analogous ortho-lithiation) and subsequent transmetalation with MgBr2 (for the method cf.

Fig. 20 Nickel-catalyzed arylation of a-chloro carbonyl compounds...

Nickel-catalyzed aryl-aryl coupling, 66, 70 m-Nitrobenzaldehyde Benzaldehyde, 3-nitro- (99-61-6), 67, 180 p-Nitrobenzoyl chloride Benzoyl chloride, 4-nitro- (122-04-3), 67, 86 2-Nitrocyclohexane-1,3-diol, (1R,2r,3S) 1,3-Cyclohexanediol, 2-nitro-,... 

To improve the nickel catalyzed arylation of alcohols and to reach a lower temperature and/or a shorter time as well as a smaller ratio of catalyst, the influence of the base was investigated more thoroughly, using the bromobenzene as arylating agent (in order to avoid any secondary reaction on the cyano group of the p-bromobenzonitrile used in the preliminary investigations) (eqn. 6) (Table 6). 

Nickel-Catalyzed Arylations of Alkyl (Pseudo)Halides... 

Nickel catalysts show a high reactivity and a broad substrate scope in the arylation of alkyl halides. While only aUcyl haUdes without P-hydrogens were used in the early examples of nickel-catalyzed arylations of alkyl halides, highly efficient arylations at the a-position of a gem-dimethyl-substituted quaternary center highlighted its synthetic potentials (Equation 5.14) [16, 17]. 

Recently, bipyridines and amino alcohols, which were rather unique ligands for conventional nickel-catalyzed cross-coupling reactions, have been shown to be eflective for nickel-catalyzed arylations of secondary alkyl halides. Fu reported that a combination of [Ni(cod)2] and bathophenanthroline 13 catalyzed the cross-... 

In 2009, Yamakawa [37] reported a nickel-catalyzed arylation of pyridines however, because KOt-Bu was also used as the base, the reaction might have undergone a radical pathway such as in Itami s results (Scheme 17.26). 

In 1970, Tavs reported the first nickel-catalyzed arylation of trialkyl phosphites or dialkyl aryl phosphonites with aryl bromides [242] (Scheme 20.72). In this reaction, trialkyl phosphite, a phosphorylating agent, plays a crucial role in the reduction of Ni(II) to active Ni(0) complex [243]. 

SCHEME 5.1 Nickel-catalyzed arylation of benzthiazole with aryl bromides. 

Nickel-Catalyzed Arylation of Benzthiazole with Aryl Bromides... 

SCHEME 5.6 Nickel-catalyzed arylation of azoles with aryl iodides. 

Nickel-Catalyzed Arylation of Azoles, Comparison of LiOf-Bu and Mg(Of-Bu)2 Protocols... 

Nickel-Catalyzed Arylation of Azoles with Phenol Derivatives... 

Iaroshenko et al. have recently described nickel-catalyzed arylations of 1-deazapurines 32 with aryl halides, using a [NiCl2(PPh3)2] catalyst and potassium carbonate in DMF at 110°C. Yields were generally excellent (88%-97%) (Scheme 5.9, Table 51) ... 

SCHEME 5.9 Nickel-catalyzed arylations of 1-deazapurines with aryl halides. 

SCHEME 5.10 Nickel-catalyzed arylation of pyridines with organozinc reagents. 

These nickel-catalyzed aryl aminations found application in molecular materials with the preparation of 1,3,5-tris(4-aminophenyl)benzenes or highly functionalized naphtidines (Figure 10.1), which possess interesting electronic properties potentially useful for molecular switches." ... 

The C2 regioselective alkenylation of pyridine is carried out using reaction conditions similar to the nickel-catalyzed arylation in the presence of stoichiometric amount of an unsymmetrical aikyne) (eq 32). ... 

In the light of the results presented by the group of Jamison and our own discoveries regarding the palladium catalyzed reaction between aryl and vinyl tosylates and electron rich olefins vide supra, it was decided to investigate the nickel catalyzed arylation of electron rich olefins in more detail [30]. 

Scheme 5.48 Enantioselective nickel-catalyzed arylation of enolates derived from racemic butyrolactones 147, mediated by (S)-BINAP (23).

---