Controllable Cyclization Reactions of 2‐(2′,3′‐Allenyl)acetylacetates Catalyzed by Gold and Palladium Affording Substituted Cyclopentene and 4,5‐Dihydrofuran Derivatives with Distinct Selectivity

摘要: Efficient room-temperature syntheses of cyclopentenes and 4,5-dihydrofurans with different substitution patterns were performed starting from the same materials (i.e., 2-(2',3'-allenyl)acetylacetates). Depending on choice metal catalyst, Au-catalyzed reaction afforded C-attack-5-endo cyclization products 2, whereas Pd-catalyzed one led to formation O-attack-5-exo 3. The selectivity may be explained by steric electronic effects substrates catalysts.