Palladium-Catalyzed Three-Component Reaction for the Synthesis of Imidazolidinones.
Once the Schlenk tube containing K2CO3 (55 mg, 0.40 mmol) is flamed, dried, and filled with argon, Tetrakis(triphenylphosphine)palladium (12 mg, 0.010 mmol), PMB-protected 2,3-allenylamine (37 mg, 0.20 mmol), iodobenzene (58 mg, 0.28 mmol), phenyl isocyanate (36 mg, 0.30 mmol), and CH3CN (4 mL) are added sequentially. The resulting solution is heated to and stirred at 70°C. When the reaction is completed as monitored by TLC, the solvent is evaporated under reduced pressure, and the residue is purified by chromatography on silica gel (petroleum ether : ethyl acetate = 7:1) to afford the corresponding imidazolidione (72 mg, Y. 96%) as an oil.
