Synthesis of Acridines from o-Aminoaryl Ketones and Arylboronic Acids by Copper Trifluoroacetate-Mediated Relay Reactions.

An efficient and practical method for the synthesis of medicinally important acridines from readily available o-aminoaryl ketones and arylboronic acids was developed using copper(II)-mediated relay reactions that involve intermolecular Chan-Lam cross-coupling and subsequent intramolecular Friedel-Crafts-type reactions. A sole promoter, i.e., Cu(OTf)2, was used; therefore, strongly acidic and basic conditions, nonreadily available or expensive substrates, additives, and noble-metal catalysts were not needed.