Synthesis of N,O-Spiroacetals and α-Arylfurans via Pd-Catalyzed Aerobic Oxidative 2,5-Aminoarylation and α-Arylation of N-[3-(2-Furanyl)propyl]-p-toluenesulfonamides with Boronic Acids

Unsaturated N,O-spiroacetals and alpha-arylfurans were synthesized via palladium-catalyzed aerobic oxidative coupling reactions between N-[3-(2-furanyl)propyl]-p-toluenesulfonamides and boronic acids, with KF and KOAc as the respective additives. These reactions involve an unprecedented dearomatizing 2,5-aminoarylation and a direct alpha-arylation of furan rings, respectively, with O-2 as the terminal oxidant.