Decarboxylative Acylation of Carboxylic Acids:Reaction Investigation and Mechanistic Study

Ketones serve as one of the most critical building blocks in organic synthesis,involving numerous functional group transformations.Herein,we rep ort an unprecedented photoredox-nickel metallap hotoredox-catalyzed decarboxylative acylation of common aliphatic acids with readily available aromatic and aliphatic thioesters.A wide range of structurally diverse asymmetrical aryl alkyl and dialkyl ketones have been constructed in yields of up to 98% with this strategy.The protocol has excellent reaction selectivity and functional group compatibility,representing a significant step forward in ketone synthesis.The one-pot decarboxylative acylation at the gram scale from two different carboxylic acids and the late-stage application for the synthesis of complex ketones shows its synthetic robustness.Both mechanistic experiments and density functional theory(DFT)calculations suggest that the decarboxylative acylation reaction operates via an underdeveloped Ni(Ⅰ)-Ni(Ⅱ)-Ni(Ⅰ)-Ni(Ⅲ)-Ni(Ⅰ)catalytic cycle.