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Denitrogenative ortho‐arylation, vinylation and methylation of 1,2,3‐benzotriazin‐4‐(3H)‐ones with organic boronic acids catalyzed by nickel complexes to give a wide range of o‐substituted benzamides were demonstrated. Further, the catalytic reaction is successfully applied to the synthesis of the popular hypertensive drugs losartan and irbesartan in high yields. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis of phenanthridinones via denitrogenative annulation of 1,2,3‐benzotriazin‐4‐(3H)‐ones with arynes catalysed by Ni(0)/dppm was successfully developed. A variety of phenanthridinones were prepared in good to excellent yields. Based on this method, nature product, N‐methylcrinasidine, was synthesized. [ABSTRACT FROM AUTHOR]

Herein, we report a nickel-catalyzed intramolecular denitrogenative dual annulation reaction of aryl nitrile-containing 1,2,3-benzotriazine-4(3 H )-ones to synthesize polycyclic pyrroloquinazolinones with a tolerance of a wide diversity of substituents. This catalytic reaction is the first denitrogenative transannulation of 1,2,3-benzotriazine-4(3 H )-one with nitrile, which can be applied as the critical step to synthesize luotonin A with a high step economy.

Herein, we report the nickel-catalyzed denitrogenative cyclization reaction of 1,2,3,4-benzothiatriazine-1,1-dioxides with arynes to generate the polysubstituted biaryl sultams with tolerance of a wide diversity of substituents on every subunit. The mechanistic study indicates that the reaction is initiated by the formation of a diradical species, which reacts with a nickel complex to form a nickelacycle intermediate and carries out the subsequent cyclization through insertion of an aryne.

A novel procedure for the transition-metal-free tandem cyclization/ N -arylation reaction sequence of an aryne with a 1,2,3,4-benzothiatriazine-1,1-dioxide is reported. This reaction goes through the intramolecular homolytic cyclization to generate an N-H biaryl sultam intermediate, which enables aryne insertion to access diversely functionalized biaryl sultam derivatives with high yields. The mechanism study indicates that homolytic cyclization is executed by a diradical species, initiated from the thermal decomposition of 1,2,3,4-benzothiatriazine-1,1-dioxide to release a nitrogen molecule.