Conjugate addition reactions of Grignard reagents

Conjugate-addition Reactions of Grignard Reagents with a,)3-... 

The synthetic application of organocopper compounds received a major impetus from the study of the catalytic effect of copper salts on reactions of Grignard reagents with y.,(i-unsaturated ketones.1 Whereas Grignard reagents normally add to conjugated enones to give the 1,2-addition product, the presence of catalytic amounts of Cu(I) results in... 

The related 6-trifluoromethyl-l,3-dioxin-4-ones underwent conjugate addition reactions with Gilman reagents, or with Grignards with copper(I) catalysis (Eq. 112). The 6-substituted compounds were also available, and were used to synthesise threonine and aZZo-threonine analogues [303]. Stark contrast between the behaviour of fluorinated and non-fluorinated compounds is revealed in Eq. (113). While benzylmagnesium chloride adds smoothly to the 6-methyl... 

Lipshutz, B. H. Hackmann, C. Conjugate addition reactions of allylic copper species derived from Grignard reagents synthetic and spectroscopic aspects./. Org. Chem. 1994, 59, 7437-7444. 

Feringa and co-workers reported a new enantioselective Cu(I)/Tol-BINAP-cata-lyzed tandem conjugate addition-enolate trapping reaction of Grignard reagents with 4-chloro-a,p-unsaturated esters, thioesters, and ketones to yield tran -l-alkyl-2-substituted cyclopropanes in up to 92% yield and up to 98% ee (Scheme 38)... 

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