An operationally simple nickel-catalyzed hydroarylation reaction for alkynes is described. This threecomponent coupling reaction utilizes commercially available alkynes and aryl bromides, along with water and Zn. An airstable and easily synthesized Ni(II) precatalyst is the only entity used in the reaction that is not commercially available. This reductive cross-coupling reaction displays a fairly unusual anti selectivity when aryl bromides with ortho substituents are used. In addition to optimization data and a preliminary substrate scope, complementary experiments including deuterium labeling studies are used to provide a tentative catalytic mechanism. We believe this report should inspire and inform other Ni-catalyzed carbofunctionalization reactions.

A Ni-catalyzed annulation reaction to synthesize indenones is reported. The reaction provides high yields and regioselectivities when aliphatic- and silyl-substituted alkynes are employed. Both have been challenging and underutilized substrate classes. Several mechanistic observations aided in the development of this reaction, including that β-hydride elimination is turnover-limiting for ortho-halogenated aldehyde substrates and that alkyne dissociation is rate-limiting for internal aliphatic alkynes. We anticipate that these methods will be rapidly adopted due to their synthetic ease and inherent versatility. We also anticipate that the mechanistic conclusions will inform further reaction development.