Rhodium(III)-Catalyzed Regioselective C-H Alkenylation and Alkylation of Menadione Analogues with β-Trifluoromethyl Enones.

Menadione and its structural analogues are important motifs present in various bioactive natural products and drugs with a wide range of biological activities. In addition, β-trifluoromethyl enone has been employed as an efficient fluorinated building block for the synthesis of CF-containing organic scaffolds. Herein, we report both C-H alkenylation and C-H alkylation reactions using β-CF enones as coupling partners with amino-substituted menadiones under Rh(III) catalysis. While β-CF enones have been studied in C-H alkylation reactions, we herein for the first time disclose the Rh (III)-catalyzed C-H alkenylation reaction of β-CF enones. The presence of an oxidant was crucial for the alkenylation reaction with β-CF enone. Meanwhile, the alkylation reaction proceeds via redox-neutral conditions.