Pd-Catalyzed cascade cyclization of o-alkynylanilines via C–H/C–N bond cleavage leading to dibenzo[a,c]carbazoles

Abstract

A new and efficient Pd-catalyzed cascade cyclization of biaryl-tethered o-alkynylanilines for the formation of dibenzo[a,c]carbazole derivatives has been reported. The use of the alkyl-substituted tertiary anilines together with the combination of the PdCl₂ catalyst with the MnO₂ oxidant and PivOH is vital for giving rise to 5-endo cyclization, C–N bond cleavage, and C–H bond activation in a cascade manner to produce the corresponding products with structural diversity.