Nickel-catalyzed reactions biaryl synthesis

Negishi, E., King, A. O., Okukado, N. Selective carbon-carbon bond formation via transition metal catalysis. 3. A highly selective synthesis of unsymmetrical biaryls and diarylmethanes by the nickel- or palladium-catalyzed reaction of aryl- and benzylzinc derivatives with aryl halides. J. Org. Chem. 1977,42, 1821-1823. 

Ullmann reaction. During a study of the synthesis of biaryls with nickel catalysts (4, 33 6, 654), Tsou and Kochi2 found that nickcl(II) complexes such as 1 readily yield biaryls on treatment with an aryl halide and that they are important intermediates in the radical-chain process of nickel-catalyzed Ullmann reactions. 

The nickel-catalyzed reductive homocoupling of haloarenes is an excellent method for the synthesis of symmetrical biaryls (Eq. 22). The remarkable ability of [Ni(cod)2] to promote the stoichiometric formation of biaryls from aryl iodides and bromides was originally reported by Semmelhack, Helquist, and Jones [25a]. Unlike the Ullmann reaction [3], the Ni-promoted homocoupling of... 

The compound 12 is an extremely useful ligand for nickel-catalyzed Grignard cross-coupling reactions and allows the enantioselective synthesis of biaryls in over 90%ee36,37 (Sections D. 1.1.3. and B.2.). 

In 2012, Yamaguchi, Itami, and coworkers [43] reported the first nickel-catalyzed decarboxylation C-H biaryl coupling of azoles with aryl esters. No stoichiometric oxidants or expensive catalysts were needed to perform this reaction. This methodology was successfully applied for the convergent formal synthesis of Muscoride A (a natural product with antibacterial activity) (Scheme 3.26). The flexibility of this approach will likely enable the preparation of a series of analogs of the Muscoride family [44]. 

In conclusion, oxidative addition of aryl halides to metallic nickel proceeded smoothly under mild conditions, and the corresponding biaryls were obtained in good yields. The present reaction is superior to the Ullmann synthesis in the scope of the reaction conditions [125] and to the coupling reaction of Grignard reagents catalyzed by transition metals [133]. Finally, because of the simple and easy procedure for the preparation of nickel powder, it is far more convenient to work with than zerovalent nickel complexes such as tetrakis(triphenylphosphine)nickel(0) or bis(l,5-cyclooc-tadiene)nickel(O) [128]. 

Saito S, Oh-tani S, Miyaura N (1997) Synthesis of Biaryls via a nickel(0)-catalyzed crosscoupling reaction of chloroarenes with atylboronic acids. J Org Chem 62 8024-8030... 

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