NHC-Catalyzed Intramolecular Hydroacylation of Unactivated Double Bonds

摘要

Thiazolium salt 1 derived N-hetero-cyclic carbene was found to efficiently promotethe hydroacylation of unactivated double bonds.In the presence of 1 and DBU several aromaticortho-allyloxy aldehydes reacted to the corre-sponding chromanones in good to excellent yields(up to 96%). The method is compatible with differ-ent functional groups on the aromatic ring and dif-ferently substituted allyl moieties, leading to all-carbon quaternary stereocenters. Finally also adihydroquinolinone was successfully synthesizedusing this new reaction. Mechanistically a certainsimilarity to the Conia-ene reactions has beennoticed by the authors.