An efficient method for the C-4-selective addition of quinoline derivatives to carbonyl compounds is described. The combination of 2-ethoxy-1-ethoxycarbonyl-1,2-dihydroquinolines (EEDQs) with a palladium catalyst and diethylzinc generates nucleophilic allyl species which undergo addition to various aldehydes and ketones. C-4-Substituted quinoline derivatives are obtained in high to excellent yields with moderate diastereoselectivities.
Key words
palladium catalysis - diethylzinc - Umpolung - dihydroquinoline - regioselectivity