Transformations of F-Alkyl Iodides and Bromides Induced by Nickel(0) Carbonyl.

Adducts of primary F-alkyl iodides with nickel carbonyl are formed readily in donor solvents and pyrolyze at 100-150 degrees C to give olefinic coupling products in high yield. The mechanism proposed to account for the observed chemistry involves preferential alpha-elimination of fluorine with formation of a carbenoid species complex coordinated to nickel. Differences in reaction paths among several types of substrate halides are rationalized on the basis of polarization of the Ni-C bond in the adducts.