Synthesis of benzocyclobutenones
In a two-step procedure to synthesize benzocyclobutenones from (o-alkylbenzoyl)phosphonates, a visible-light-driven cyclization reaction forming phosphonate-substituted benzocyclobutenols is followed by an elimination reaction of the H-phosphonate as the recyclable auxiliary. The method provides access to a wide variety of functionalized benzocyclobutenones, including those difficult to synthesize by conventional methods.
T. Yano, T. Kawasaki, T. Yuhki, N. Ishida, M. Murakami, Org. Lett., 2018, 20, 1224-1227.
A palladium-catalyzed intramolecular acylation of aldehydes with aryl bromides via C-H functionalization is distinguished by a remarkable functional group tolerance and hence enables the synthesis of various highly functionalized benzocyclobutenones from simple and easily accessible precursors.
P. Álvarez-Bercedo, A. Flores-Gaspar, A. Correa, R. Martin, J. Am. Chem. Soc., 2010, 132, 466-467.