Pd-catalyzed selective carbonylative and non-carbonylative couplings of propiolic acid: one-pot synthesis of diarylalkynones.

Diarylalkynones were synthesized from one-pot Pd-catalyzed carbonylative and noncarbonylative coupling reactions of propiolic acid with aryl iodides under a carbon monoxide atmosphere. Aryl iodide (2.0 equiv), propiolic acid (1.0 equiv), Pd(PPh3)2Cl2 (5 mol %), CuCl (10 mol %), Et3N (6.0 equiv), and CO (8 atm) were reacted under optimized conditions in CH3CN at 80 °C for 1 h. This process afforded good yields and functional group tolerance.