Palladium-Catalyzed Carbonylative Negishi-Type Coupling of Alkyl Zinc Reagents with Benzyl Bromides.

The first Pd-catalyzed carbonylative Negishi-type reaction allowing coupling of C(sp3)-hybridized benzyl bromides with C(sp3)-hybridized organozinc reagents is described. The protocol relies on the PEPPSI-IPr precatalyst and ex situ-generated CO gas at atmospheric pressure (balloon) to furnish benzyl alkyl ketones. The method requires no special equipment and tolerates an excess of CO and a broad variety of functional groups.