Enantioselective Radical Hydroacylation of Enals with α-Ketoacids Enabled by Photoredox/Amine Cocatalysis.

A photoredox/amine-cocatalyzed enantioselective radical hydroacylation of enals with α-ketoacids is described. Acyl radicals generated from α-ketoacids act as the acylation reagent with the iminium ions. This strategy provides an efficient way to access synthetically challenging 1,4-dicarbonyl compounds in an enantioselective manner. The reactions of various enals with α-ketoacids show the generality and limitations of this method.