Synthesis of 2,3-Benzotropones via Palladium(II)-Catalyzed Aerobic Dehydrogenation from 1-Benzosuberones and Sequential Diels-Alder Reaction to Yield Benzobicyclo[3.2.2]nonenones.

An approach to 2,3-benzotropone from 1-benzosuberone via palladium(II)-catalyzed aerobic dehydrogenation was developed. This method first provided a catalytic route to various 2,3-benzotropones from their corresponding 1-benzosuberones in good yields. In addition, the reaction could be applied to a one-pot Diels-Alder reaction with maleimide, providing a complex benzobicyclo[3.2.2]nonenone in ≤90% yield. Kinetic analysis supporting our proposed mechanism was also performed, underscoring the robustness of the developed synthetic pathway.

Synthesis of Xanthones via Copper(II)-Catalyzed Dehydrogenative Cyclization and Successive Aromatization in a One-Step Sequence.

In this study, an unprecedented approach to the xanthone scaffold from cyclohexyl(2-hydroxyphenyl)methanone via dehydrogenative cyclization and a successive aromatization cascade is reported. This methodology affords a novel route to the privileged structure with a wide substrate scope (a total of 29 compounds, ≤96% yield) in a highly atom-economic manner.

Synthesis of meta-(Indol-3-yl)phenols from Indoles and Cyclohexenone via Palladium(II)-Catalyzed Oxidative Heck Reaction and Dehydrogenative Aromatization in a One-Step Sequence.

Facile construction of a meta-(indol-3-yl)phenol framework with a wide substrate scope (a total of 25 compounds) via a palladium(II)-catalyzed oxidative Heck reaction and dehydrogenative aromatization in a one-step sequence is reported. This methodology affords a novel route for the privileged structures that are challenging to access via a direct link between indole and phenol, in a highly efficient and atom-economical manner.