Ferrocenylphosphine nickel catalyst

The ferrocenylphosphine-nickel catalysts are also applied to asymmetric synthesis of axially chiral biaryl compounds through the cross-coupling reaction. Although initial attempts to this... 

Scheme 2.34 Conjugate addition of cyclic amines to methacrylonitrile with a preformed ferrocenylphosphine nickel catalyst.

Hydrogenation of substituted aromatic a-amino ketone hydrochlorides in the presence of an in situ generated nickel catalyst derived from a ferrocenylphosphine ligand. 

Hayashi T, Hayashizaki K, Kiyoi T, Ito Y. Asymmetric synthesis catalyzed by chiral ferrocenylphosphine-transition-metal complexes. 6. Practical asymmetric synthesis of 1,1 -binaphthyls via asymmetric cross-coupling with a chiral [(alkoxyalkyl)ferrocenyl] monophosphine/nickel catalyst. J. Am. Chem. Soc. 1988 110(24) 8153-8156. 

A large fraction of the catalysts investigated for this purpose is on the basis of palladium or nickel complexes with chiral ferrocenylphosphine derivatives. This interest was spurred by the early work of Hayashi and Kumada who achieved the asymmetric coupling depicted in equation (5) (R = H) in 68% ee using phosphine (3) to provide chirality at the catalytic center. More recently, Knochel synthesized bisphosphine derivative (4) (R = Ph) which gave results similar to (3) when vinyl bromide was the substrate (equation 5, R = H, 63% ee). However, when the reaction was performed with /3-bromostyrene (R = Ph), the enantioselectivity see Enantioselectivity) increased to 93%. 

The asymmetric cross-coupling of 1-phenylethylmagnesium chloride 20a with vinyl bromide 21 a has been reported by Hayashi and Kumada to proceed in the presence of 0.5 or 1 mol% of nickel or palladium catalyst coordinated with a chiral ferrocenylphosphine ligand to give optically active 3-phenyl-1-butene 22 [28]. 

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