Deciphering the Origin of Divergent Cycloisomerization Pathways in Gold(I)‐ and Silver(I)‐Catalyzed Reactions of 1,9‐Dien‐4‐yne Ester

Experimental studies have shown that gold(I)‐ and silver(I)‐catalyzed cycloisomerization of 1,9‐dien‐4‐yne esters affords distinct products. To elucidate the origin of this metal‐dependent selectivity, we performed a comprehensive density functional theory (DFT) investigation of the corresponding catalytic reactions. The calculated mechanisms reveal that both reactions involve a series of elementary steps associated with transformations between σ ‐ and π ‐coordinated metal intermediates. Comparative analysis shows that the divergent reactivity originates from intrinsic differences in the σ ‐ and π ‐coordination preferences of Au(I) and Ag(I). In particular, Au(I) exhibits a substantially stronger preference for σ ‐coordination relative to π ‐coordination than Ag(I), which alters the accessibility of key intermediates and transition states and ultimately directs the reactions toward different cycloisomerization products.