Nickel-Catalyzed Reductive 1,4-Alkylacylation of 1,3-Enynes Enabling Synthesis of Allenyl Ketones.

A nickel-catalyzed reductive 1,4-alkylacylation of 1,3-enynes has been established using nonactivated tertiary alkyl bromides and aromatic anhydrides as dual electrophiles. This protocol enables efficient assembly of tetrasubstituted allenyl ketones with high chemo- and regioselectivity. Mechanistic insights reveal the radical relay process involving the synergistic interactions of nickel and zinc. The allenyl ketone products serve as modular building blocks, particularly for constructing fully carbon-substituted furans via Au-catalyzed cycloisomerization with selective 1,2-aryl migration, enhancing the synthetic practicality.