Efficient Synthesis of Dibenzo[a,c]cyclohepten-5-ones via a Sequential Suzuki−Miyaura Coupling and Aldol Condensation Reaction

A common strategy for the synthesis of a 7-membered-ring system with a Suzuki−Miyaura coupling followed by an acid/base-promoted intramolecular aldol condensation reaction has been developed. The reaction of 2′-bromoacetophenones with 2-formylphenylboronic acids in the presence of Pd(OAc)2 and CataCXium PIntB L8 efficiently provided biaryl compounds, which were transformed to a wide array of dibenzo[a,c]cyclohepten-5-ones in excellent yields by a sequential treatment with p-TsOH, followed by 10% aq NaOH.