A regioselective arylative cyclization of ortho functional diaryl acetylenes for the synthesis of selectively substituted diaryl pyridine and indene derivatives is accomplished through an electrophile driven alkyne polarization.

A syn-arylative nickelation followed by nucleophilic syn-selective cyclization of o-propargyloxy benzaldehydes is achieved toward the synthesis of chromanol skeletons with alkenyl substitution at C3. The capture of the intermediate vinyl nickel in its cis geometry is done also with a Michael acceptor to synthesize 4-alkylated derivatives. This protocol is equally applicable to opropargylamino benzaldehydes to access 3,4-disubstituted tetrahydro-hydroquinolines.

In the realm of transition-metal catalyzed arene functionalization, rhodium(III) catalysis is considered as exemplary due to its propensity to activate C−H bonds to obtain comprehensive molecular assembly. Herein, we demonstrate a new rhodium(III) catalyzed assembly of polyheterocyclic scaffolds via C−H activation and regioselective annulation of 4-arylbut-3-yn-1-amines with 4-hydroxy-2-alkynoates. Heterocyclization and transmetalation prior to annulation is the key for initiation of this relay redox-neutral catalytic cascade.