Gold(I)‐Catalyzed Allylation and Tandem Allylation–Cycloisomerization of Stannylated Propargyl Acetates with Allylsilanes

Bicyclo[3.1.0]hex‐2‐enes, synthesized by the cycloisomerization of 1,5‐enynes, serve as key scaffolds in various natural products. Gold(I)‐catalyzed cycloisomerization of 1,5‐enynes is an efficient route to bicyclo[3.1.0]hex‐2‐enes. However, gold(I)‐catalyzed 1,5‐enyne synthesis, particularly with a terminal alkyne, has not yet been fully explored. This study presents a mild and general method for the gold(I)‐catalyzed allylation and tandem allylation–cycloisomerization of stannylated propargyl acetates with allylsilanes, yielding 1,5‐enynes with terminal alkyne moiety and bicyclo[3.1.0]hex‐2‐enes. The catalytic system ((4‐MeOC 6 H 4 ) 3 PAuCl/AgSbF 6 ) enabled the efficient synthesis of 1,5‐enynes with good to high yields and regioselectivities. In addition, gold(I)‐catalyzed tandem allylation–cycloisomerization using (JohnPhos)Au(MeCN)SbF 6 afforded bicyclo[3.1.0]hex‐2‐enes with high regiocontrol. Stannylated propargyl acetates proved crucial in enhancing selectivity for both product classes.