Radical Acylalkylation of 1,3-Enynes To Access Allenic Ketones via N -Heterocyclic Carbene Organocatalysis.

An N -heterocyclic carbene organocatalytic 1,4-difunctionalization of 1,3-enynes was developed. This organocatalytic strategy was suitable for a broad spectrum of substrates to efficiently synthesize allenic ketones bearing diverse substituents. Preliminary mechanistic studies suggest a radical reaction pathway for this organocatalytic acylalkylation process.