Controllable Chemoselectivity Cascade Reactions for the Synthesis of Phenanthrenols via Palladium-Catalyzed-Suzuki/Heck Reaction and Michael Addition

Palladium serves as a multi-functional catalyst which is controllable by tuning reaction conditions. This work demonstrated the utilization of a palladium catalyst for the synthesis of phenanthrenols by cascade palladium-catalyzed Suzuki/Heck reaction between chalcone and 2-bromophenylboronic acid, followed by Michael addition. The sequential reaction could be controlled by reactivity of the palladium catalyst in different solvents and concentrations of reagents. This protocol could be applied to a broad range of substrates to give products in low to good yields. Palladium, a versatile catalyst, is controllable via reaction conditions tuning. This research highlights the palladium catalyst's application in synthesizing phenanthrenols through a sequential cascade of Suzuki/Heck reactions between chalcone and 2-bromophenyl-boronic acid, followed by Michael addition. The order of reactions can be adjusted by manipulating solvent types and reagent concentrations, influencing the palladium catalyst's reactivity. image