Ligand-Controlled Switchable Synthesis of Fused Polycycles by Selective 1,4-Palladium Migration

The palladium migration strategy has been employed for the functionalization of remote C─H bonds, offering an efficient approach to construct fused heterocycles. In this study, a novel ligand-controlled switchable synthesis of fused quinolinone skeletons from 1,7-enynes and perfluoroalkyl iodides via selective 1,4-palladium migration is disclosed. When DPEphos is used as the ligand, vinyl-to-aryl 1,4-palladium migration is promoted, affording a wide range of perfluoroalkyl-containing 4,5,10-fused quinolinone derivatives. In contrast, the use of DPPPy as the ligand facilitates vinyl-to-alkyl 1,4-palladium migration, yielding various perfluoroalkyl-containing 3,4-fused quinolinone derivatives. Notably, this protocol also enables modifications of various drug molecules. DFT calculations have been conducted to elucidate the cis-trans isomerization pathways of alkenyl palladium intermediates with different ligands.