Cross-coupling reactions asymmetric Grignard

A polystyrene-bound chiral aminophosphine-Ni(II) chloride complex catalyzes the asymmetric cross-coupling reaction of a secondary alkyl Grignard reagent with vinyl bromide in a moderate optical yield (25). 

Recently, the use of a chiral catalysts in the asymmetric biaryl synthesis has received some attention. Unsymmetrical chiral binaphthyls can be obtained in high enantiomeric excess by SnAt reactions of naphthylimines such as 39 with lithium bromide free 1-naphthyllithium catalysed by a chiral ether ligand 40 (ref. 29). Another example is the Ni(0) catalysed cross coupling of naphthyl Grignard reagents and naphthyl bromides in the presence of a chiral ferrocene ligand (ref. 30). 

Asymmetric cross coupling of the Grignard reagent from 2-methoxy-1-bromonaphthalene with menthyl 1-(-)menthoxy-2-naphthoate in ether/benzene (1 1) by reaction at ambient temperature for 3 hours followed by gentle refluxing for 2 hours, gave the product shown in 81% yield with an optical purity of 98% (ref. 13). 

Asymmetric synthesis by the catalytic cross-coupling reaction has been studied most extensively with secondary alkyl Grignard reagents. Asymmetric cross-coupling with... 

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