Gold-Catalyzed Regioselective Oxyfluorination/Oxydifluorination vs. Diketonization of Phthalimido-Protected Propargylamines with Selectfluor

Alkyl- and aryl-substituted N-propargyl phthalimides were used as valuable building blocks for the selective formation of the corresponding α-fluoro, β-phthalimido ketones, α,α-difluoro, β-phthalimido ketones or β-phthalimido α-diketones by means of gold-catalyzed oxyfluorination/oxydifluorination or dioxygenation reactions. The key factors addressing the product selectivity control were determined. The simultaneous assembly of the quinoxaline nucleus and the removal of the phthalimidoprotecting group were tested. Reaction mechanisms of the different reaction pathways are assumed.