Palladium(0)-Catalyzed Carbonylation−Coupling−Cyclization of Allenic Sulfonamides with Aryl Iodides and Carbon Monoxide
摘要:
[GRAPHICS]alpha-Allenic sulfonamides undergo carbonylation-coupling-endo-cyclization with aryl iodides in the presence of Pd(PPh3)(4) (5 mol %), K2CO3, and CO (20 atm) to form 3-aroyl-2 or 3-pyrrolines. Alternatively the carbonylation-coupling-exo-cyclization of gamma- and delta -substituted sulfonamides under the same conditions afforded pyrrolidine or piperidine substituted enones.