Synthesis of Phenanthrone Derivatives from sec-Alkyl Aryl Ketones and Aryl Halides via a Palladium-Catalyzed Dual C-H Bond Activation and Enolate Cyclization

摘要

Recently, palladium-catalyzed direct transformations of inactivated C-H bonds into various functional groups has emerged as a powerful method in organic synthesis. In particular, reactions involving directing-group-assisted activation of sp or sp C-H bonds of ortho aromatic or alkenyl C-H bonds have been extensively investigated. In general, this type of ortho C-H bond activation involves a five-membered cyclometalation reaction. The directing groups frequently used in these C-H bond activation reactions include aldehyde, oxime, imine, alcohol, amine, carboxylic acid, phenol, and nitrile.