Divergent Synthesis of Naphthalenone Spiroindanediones or 4‐Acyl‐1‐naphthols from Aryl Enaminones Featuring Reuse of Dimethylamine

Abstract Presented herein is a switchable synthesis of naphthalenone spiroindanediones or 4‐acyl‐1‐naphthols via condition‐controlled divergent cascade reactions of aryl enaminones with diazoindanediones. When the reaction was carried out in the presence of an oxidative additive, naphthalenone spiroindanedione was formed through C( sp 2 )−H alkylation followed by simultaneous spiroannulation and elimination of dimethylamine. When the reaction was carried out in the presence of an acid additive, on the other hand, 4‐acyl‐1‐naphthol was formed through ring opening of the spiroindanedione moiety attacked by the in situ released dimethylamine. In addition, the reactions are suitable for gram‐scale applications and compatible with a variety of substrates. Moreover, the naphthol products allow structural elaborations and hybridization with a drug, thus further enhancing the value of this developed method.