Carbonylative coupling of phenylethyne with 4-methoxy-1-iodobenzene in the presence of 1 mol% PdCl2 (PPh3) 2, 2 equiv of 0.5 M aqueous ammonia, and CO (1 atm) gives the corresponding α, β-alkynyl ketone in 72% isolated yield after stirring at room temperature for 41 h, while noncarbonylative coupling product is not obtained.
