Ni-Catalyzed Kumada-Corriu Cross-Coupling Reactions of Tertiary Grignard Reagents and Bromostyrenes.

The development of protocols for the construction of congested quaternary centers is highly sought-after. Herein, we report a method for the cross-coupling of C(sp ³ ) tertiary Grignard reagents with C(sp ² ) styrenyl bromides using readily available nickel precatalysts. We identified conditions that afford the products in practical yield for several combinations of electrophiles and nucleophiles, including sensitive α-magnesiated Grignard reagents. Dependent upon the nature of their substituents, regiodivergency was observed when α-vinyl bromides were employed.