Pd-Catalyzed Intramolecular Heck Reaction, C(sp2)-H Activation, 1,4-Pd Migration, and Aminopalladation: Chemoselective Synthesis of Dihydroindeno[1,2,3-kl]acridines and 3-Arylindoles

Palladium-catalyzed intramolecular Heck reaction and aminopalladation of N-(2-(1-phenylvinyl)phenyl)-aniline for the efficient synthesis of dihydroindeno [1,2,3-kl]acridines and 3-arylindoles via tuning of the phosphine ligands and solvents under two optimized conditions are reported. The reaction follows a 1,4-Pd migration, aminopalladation, C(sp(2))-H activation, as well as five- and six-membered-ring fusion to form different products. The dihydroindeno[1,2,3-kl]acridine derivatives showed higher triplet energy (E-T) levels than common blue phosphorescent dopant and may serve as good host candidates for blue triplet emitters.