Palladium-Catalyzed Regioselective Coupling Cyclohexenone into Indoles: Atom-Economic Synthesis of β-Indolyl Cyclohexenones and Derivatization Applications
Herein, we report a palladium-catalyzed dehydrogenative cross-coupling of indoles with cyclic enones to give β-indolyl cyclic enones under mild and neutral reaction conditions. The key to the success is to explore a mild condition, which ensures the indole C-H activation and subsequent syn β-hydride elimination through rapid enolization isomerization of Pd(II)-enolate while suppressing other undesired side reactions. Synthetic utility has also been demonstrated in the flexible transformation of the coupling products to meta-phenols and benzo[a]carbazoles.
Visible-Light Mediated ortho-Trifluoromethylation of Aniline Derivatives
A general visible-light mediated ortho-C-H trifluoromethylation of aniline derivatives by using a low-cost and stable Langlois reagent (CF3SO2Na) as the "CF3" source has been developed. In contrast to previous reports, this strategy allowed access to elusive trifluoromethyl lactams. Furthermore, mechanism experiments revealed that a copper/photoredox dual catalytic mechanism enabled general trifluoromethylation of aniline derivatives.