Highly enantiomerically enriched dihydrohydroquinolines were prepared in two steps from quinoline. Addition of aryllithiums to quinoline with tert‐butoxycarbonyl (Boc) protection gave N‐Boc‐2‐aryl‐1,2‐dihydroquinolines. These were treated with n‐butyllithium and electrophilic trapping occurred exclusively at C‐4 of the dihydroquinoline, a result supported by DFT studies. Variable temperature NMR spectroscopy gave kinetic data for the barrier to rotation of the carbonyl group (ΔG≠≈49 kJ mol−1, 195 K). Lithiation using the diamine sparteine allowed kinetic resolutions with high enantioselectivities (enantiomer ratio up to 99 : 1). The enantioenriched 1,2‐dihydroquinolines could be converted to 1,4‐dihydroquinolines with retention of stereochemistry. Further functionalisation led to trisubstituted products. Reduction provided enantioenriched tetrahydroquinolines, whereas acid‐promoted removal of Boc led to quinolines, and this was applied to a synthesis of the antimalarial compound M5717.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.