A nickel-catalyzed reductive cross-coupling reaction of aryl cyclopropyl ketones with easily accessible unactivated alkyl bromides to access aryl alkyl ketones has been developed. This strategy facilitates access to various of γ-alkyl-substituted ketones via ring opening of cyclopropyl ketones (26 examples, 50–90% yield). Initial mechanistic studies revealed that the reaction proceeds via radical cleavage of the alkyl bromide.

A direct and convenient method for the palladiumcatalyzed reductive cross-coupling of aryl iodides or alkenyl bromides and secondary benzyl halides under ambient CO pressure to generate a diverse array of aryl/alkenyl alkyl ketones has been developed. This strategy successfully achieves a three-component carbonylative reaction with Zn as the reducing agent for CÀ C bond formation, overcoming the well-known homocoupling of aryl or alkenyl halides, direct cross-coupling between two different electrophiles and other carbonylative coupling reactions. In addition, this method avoids use of preformed organometallic nucleophiles, such as organo-magnesium, zinc and boron reagents. This approach enables the construction of valuable aryl alkyl/ alkenyl ketone derivatives (60 examples, 56-95% yields).Reactivity studies indicate that in situ formed benzylic zinc reagents are intermediates in the catalytic system.

The nickel-catalyzed cross-electrophile coupling of 1,2,3-benzotriazin-4(3H)-ones with aryl bromides to generate a diverse array of ortho-arylated benzamide derivatives has been developed. The reaction displayed good functional group tolerance with Zn as the reductant. The key to this transformation is the ring opening of benzotriazinones, which undergo a denitrogenative process to obtain various benzamide derivatives (29 examples, 42−93% yield). The scalability of this transformation was demonstrated.