Acylation of electrophilic olefins through decatungstate-photocatalyzed activation of aldehydes

Ketones were prepared by the photocatalytic generation of acyl radicals from aldehydes and trapping them with equimolar amounts of electrophilic alkenes. Photocatalysis with tetrabutylammonium decatungstate is effective also at low temperatures (−20 to −50 °C), thus minimizing radical decarbonylation and allowing acylation by highly substituted aldehydes.