Homo coupling, disproportionation and cross coupling of alkyl groups. Role of the transition metal catalyst

Silver is an effective catalyst for the homo coupling of the Grignard reagent and alkyl halide when both alkyl groups are the same. Copper(I) catalyzes the cross coupling of Grignard reagents and alkyl bromides when carried out in tetrahydrofuran solutions at low temperatures. Facile vinylation of the Grignard reagent can be achieved with alkenyl bromides using an iron catalyst. Oxidation-reduction concepts are important in the formulation of these catalytic processes. (C) 2002 Published by Elsevier Science B.V.