Visible-light or sunlight-driven copper catalysis for base-free synthesis of β-diketones via radical acylation of enol silyl ethers

A mild and sustainable method for the synthesis of β-diketones has been developed via visible-light- or sun-light-driven, copper-catalyzed acylation of enol silanes with acyl chlorides. This protocol departs from traditional two-electron pathways by employing a radical-mediated role-reversal strategy that effectively suppresses side reactions such as over-acylation and oxo-acylation. The reaction proceeds under operationally simple conditions and allows for gram-scale synthesis. Furthermore, the resulting β-diketones, as versatile synthetic intermediates, were readily converted into α-diketones, enamine derivatives and heterocyclic scaffolds.