Synthesis of Phenanthridinones from N‐Methoxybenzamides and Arenes by Multiple Palladium‐Catalyzed CH Activation Steps at Room Temperature

Abstract

Many steps make light work: substituted phenanthridinones can be obtained with high regioselectivity and in very good yields by palladium-catalyzed cyclization reactions of N-methoxybenzamides with arenes. The reaction proceeds through multiple oxidative C-H activation and C-C/C-N formation steps in one pot at room temperature, and thus provides a simple method for generating bioactive phenanthridinones.

Palladium(II)-Catalyzed Enantioselective C(sp3)–H Activation Using a Chiral Hydroxamic Acid Ligand

“…Inspired by our previous finding that the O -methylhydroxamic acid group is highly efficient in facilitating Pd(II)–catalyzed C–H bond activation, 23,24 we converted N -Boc-leucine to the corresponding O -methylhydroxamic acid L7 . The stronger coordination between this ligand and the Pd(II) center could also further rigidify the transition state and improve the stereoselection.…”

Rhodium(III)‐Catalyzed Oxidative CH Coupling of N‐Methoxybenzamides with Aryl Boronic Acids: One‐Pot Synthesis of Phenanthridinones

“…[13] Further application of this methodology in natural product synthesis is in progress. The catalytic reaction proceeds with high regioselectivity and provides various substituted phenanthridinones through C À C and C À N bond formation in very good yields.…”

A Cross‐Dehydrogenative Annulation Strategy towards Synthesis of Polyfluorinated Phenanthridinones with Copper

“…Recently, transition‐metal‐catalyzed oxidative coupling of C−H bonds, the so‐called cross‐dehydrogenative coupling (CDC), has emerged as a powerful strategy to construct C−C bonds. In 2015, Cheng group have demonstrated the power of this strategy in the synthesis of phenanthridinones under palladium catalysis (Scheme a) . Intrigued by this report and the importance of fluorinated analogues mentioned above, we envisioned that direct cross‐coupling between benzamides and polyfluoroarenes such as pentafluorobenzene could be a convenient route to access polyfluorinated phenanthridinones (Scheme ) .…”