Nickel-mediated cross-coupling of unactivated neopentyl iodides with organozincs

초록

(dppf)NiCl2 catalyzes the cross-coupling of unactivated primary neopentyl iodides with diorganozinc reagents. The zinc nucleophiles are formed by the treatment of ZnCl2.dioxane with 2 mol equiv of a Grignard reagent in an ethereal solvent. The cross-coupling works optimally for diorganozincs formed from aryl chlorides or CH3MgCl. Use of aryl bromides can cause reduction and/or reductive dimerization of the electrophile. The analogous reaction with (CH3)2CuMgCl in either the presence or the absence of Group 10 metal catalysts failed to afford reasonable yields of cross-coupled products. The diorganozinc methodology overcomes many of the side reactions observed with the (dppf)-NiCl2-mediated cross-coupling of Grignard reagents.

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