Direct 1,2-Dicarbonylation of Alkenes towards 1,4-Diketones via Photoredox Catalysis

1,4-Dicarbonyl compounds are intriguing motifs and versatile precursors in numerous pharmaceutical molecules and bioactive natural compounds. Direct incorporation of two carbonyl groups into a double bond at both ends is straightforward but extremely challengeable. Represented herein is the first example of 1,2-dicarbonylation of alkenes by photocatalysis. Key to success is that N( n -Bu) 4 + not only associates with alkyl anion to avoid protonation but also activates α -keto acid to undergo electrophilic addition, where α -keto acid is employed both for acyl generation and electrophilic addition. By tuning the reductive and electrophilic ability of acyl precursor, unsymmetric 1,2-dicarbonylation is achieved. This metal-free, redox-neutral and regioselective 1,2-dicarbonylation of alkenes is executed only by a photocatalyst for versatile substrates under extremely mild condition that is appealing to great application prospect in biomolecular and drug molecular derivatization.