Grignard reagents halides, palladium catalysis

Recently, this reaction has been extensively studied since it is currently the only method to couple aryl Grignard reagents with secondary alkyl halides Indeed, secondary aUtyl halides do not react under palladium or nickel catalysis . On the other hand, let us recall that the coupling of secondary alkyl Grignard reagents with aryl halides leads to poor results (see above). 

Reaction with Alkyl Halides. The Grignard reagent (1) can be alkylated by allyl halides to afford the homoallylsilane. The use of a nickel(II) catalyst facilitates coupling of the Grignard reagent (1) to vinyl halides and aryl halides, triflates and O-carbamates and provides a useful method for the preparation of allyl- andbenzylsilanes (eq 7). Palladium catalysis is also effective to couple (1) with vinyl halides. 

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