Substituent‐Controlled Regiodivergent Palladium‐Catalyzed Annulative Dearomatization of Phenols toward Skeletally Diverse Spirocyclohexadienones

Abstract

AbstractA palladium‐catalyzed intermolecular dearomative formal [4+2] annulation of phenols with propargyl electrophiles is reported, enabling substituent‐controlled regiodivergent synthesis of a wide range of skeletally diverse spirocyclohexadienones with good yields. The regiodivergence could be precisely controlled by adjusting the steric hindrance of O‐ and N‐substituents from binucleophilic substrates, where substrates with an O‐nucleophilic site were converted into spiro[chromane‐4,1′‐cyclohexane]‐2′,5′‐dien‐4′‐ones with complete regioselectivity and (Z)‐selectivity, whereas N‐nucleophiles enabled a different regiodivergent process to access spiro[cyclohexane‐1,4′‐quinoline]‐2,5‐dien‐4‐ones.