Palladium-catalyzed heteroannulation with acetylenic carbinols as synthons-synthesis of quinolines and 2,3-dihydro-4(1H)-quinolones

Abstract o -Iodoanilides 4 reacted with terminal acetylenic carbinols 5 under palladium-catalyzed conditions to yield o -substituted anilides 6 . Most of the anilides 6 could be cyclized with NaOEt/EtOH to 2-arylquinolines 2 . o -Iodoanilines 7 reacted with carbinols 5 leading to 8 which on palladium(II) assisted cyclisation afforded substituted quinolines 2 . An excellent synthesis of the alkaloid dubamine (2n) is reported. Also, the anilides 6 on acid-catalyzed rearrangement, deprotection and cyclisation led to the 2-aryl-2, 3-dihydro-4(1H)-quinolones 16 .