Synthesis of 2,3-disubstituted indenones by cobalt-catalyzed [3+2] annulation of o-methoxycarbonylphenylboronic acid with alkynes

Abstract

Treatment of alkynes with o-methoxycarbonylphenylboronic acid in the presence of a cobalt catalyst resulted in the corresponding 2,3-disubstituted indenones in good yields. Excellent regioselectivities were observed, when silyl aryl alkynes were used. The intermediate 3-silyl-2-aryl-substituted indenones were converted to 2,3-diaryl indenones by a three-step protocol involving C–Si bromination and Suzuki–Miyaura coupling reaction.