A Four-Component Cascade C–H Functionalization/Cyclization/Nucleophilic Substitution Reaction To Construct α‑Functionalized Tetrahydro­quinolines by the Strategy of in Situ Directing Group Formation

A four-component cascade C–H functionalization/cyclization/nucleophilic substitution reactions of anilines, carboxylic anhydrides, propenol, and alkohols have been developed by a strategy of in situ directing group formation, affording an efficient and convenient synthesis of α-alkoxyl tetrahydro­quinolines from basic starting materials. A plausible mechanism involving rhodium­(III) catalytic C–H functionalization and double nucleophilic attacks is proposed. The nucleophilicity order of some alcohols is also obtained for the cascade reaction.