A palladium-catalyzed C-H bond activation reaction, via a redox-neutral pathway, for the preparation of dihydrophenanthridine, phenanthridine, and carbazole derivatives from biaryl 2-iminoquinones is developed. The preinstalled iminoquinone was designed to act as a directing group for ortho C-H activation and an internal oxidant or a co-oxidant. This catalysis proceeded through the following sequence: C-H bond activation, coordination and insertion of activated olefins, β-hydride elimination, H-shift, insertion, and protonation or β-hydride elimination. In addition, carbazoles can be prepared efficiently by using this method without the addition of external oxidants.

Palladium-catalyzed cycloaromatization of N-acyl-2-aminobiaryls, through a sequence of ortho CÀH bond activation/alkyne insertion/meta CÀH bond activation/alkyne insertion, was developed. An efficient synthesis of multiaryl-substituted naphthalenes, N-[2-(5,6,7,8-tetraarylnaphthalen-1yl)aryl]acetamides, was demonstrated using molecular oxygen as the sole oxidant. Furthermore, through Buchwald's synthetic protocol, two compounds were converted into corresponding fluorescent carbazoles in 30-40% yield by intramolecular CÀN bond formation.

We report the first example of Pd(II)catalyzed highly step-and atom-economical benzofulvenation through free amine-directed ortho CÀH bond activation of o-arylanilines. This paper presents a novel, simple, and efficient approach for the synthesis of benzofulvene derivatives from oarylaniline substrates through CÀH bond activation with two diarylacetylenes as an implicit benzofulvene unit. The reactivity of synthesized benzofulvenes toward oxidation was investigated, and they were shown to transform into phenanthridines, oxabenzofulvenes, and fluorescent polycyclics.

We developed palladium-catalyzed oxidative coupling of olefins with N-acyl 2-aminobiaryls through a sequence of ortho C-H bond activation/alkene insertion/reductive elimination. Furthermore, we controlled the selectivity of mono- and bis-alkenylation products with the solvent effect. The developed protocol was promising for a broad substrate scope ranging from activated olefins with a wide variety of functional groups to unactivated olefins.

A new class of iptycenes was developed by combining 2-(naphthalen-1-yl)anilines and p-benzoquinones through copper(ii)-mediated radical cyclisation. This unusual cyclisation reaction resulted in the robust and efficient syntheses of iptycenes with an acridinone motif. These iptycenes can be further transformed into planar acridinone heterocyclics through the Diels-Alder reaction.