Green photochemistry: photo-Friedel–Crafts acylations of 1,4-naphthoquinone in room temperature ionic liquids

The photo-Friedel–Crafts acylation of 1,4-naphthoquinone with various aldehydes was investigated in a series of room temperature ionic liquids. High conversions and selectivities were achieved in [C2mim]+-based ionic liquids with the highest isolated yields found in [C2mim][NTf2]. The developed procedure allowed for a replacement of hazardous solvents such as benzene and acetonitrile which are commonly used for this transformation