The first use of cationic silver (AgSbF4) as a catalyst for intra-and intermolecular alkyne- carbonyl coupling to form conjugated enones is described, and a comparison to corresponding Brønsted acid (HBF4) and Lewis acid (BF3) catalyst systems is made. Notably, intermolecular coupling proceeds stereoselectively to afford the corresponding trisubstituted enones as single geometrical isomers. This transformation represents a ...