Lewis Acid‐Controlled Cyclization of Ynones and Sulfinic Acids to Access Sulfonyl and Sulfinyl Naphthalen‐2‐ols

Herein, a switchable synthesis of 3‐sulfonyl and sulfinyl naphthalen‐2‐ols via Lewis acid‐promoted cyclization of 1‐arylbut‐3‐yn‐2‐ones and sulfinic acids under redox‐free conditions was developed, thus providing concise access to structurally diverse functionalized 2‐naphthols and sulfur‐centers. This transformation conducted smoothly under mild reaction conditions with a broad substrate scope, easily handled starting materials and moderate to good efficiencies. Furthermore, the synthetic value of this logic was demonstrated by the practical and diverse late‐stage transformations of products. The preliminary mechanisms were also proposed based on a series of control experiments.