Synthesis of Quinolines by Catalyzed Cyclodehydration of Aminoaryl-2-yn-1-ols

Significance

A general synthesis of substituted quinolines through a copper- or palladium-catalyzed 6-endo-dig annulation-dehydration of amino­aryl-2-yn-1-ols, easily prepared using readily available acetylenic Grignard reagents, is reported. The reaction may be carried out in one pot, which is of significance since the aminoaryl-2-yn-1-ols are unstable towards purification. Unfortunately, the reaction of TMS alkynes (R⁴ = TMS) led to a loss of the TMS group. Otherwise, the availability of TMS-substituted quinoline products may open new routes for further desilylative substitution chemistry. The scope of the reaction with respect to substitution on both reaction partners was inadequately tested.