Synthesis of -Methylated Benzamides via Palladium-Catalyzed Denitrogenative Cross-Coupling Reaction of [1,2,3]-Benzotriazin-4(3)-ones with DABAL-Me.

We herein developed a palladium-catalyzed reaction of [1,2,3]-benzotriazin-4(3)-ones with DABAL-Me [bis(trimethylaluminum)-1,4-diazabicyclo[2.2.2]octane adduct], a cheap, stable, and solid organoaluminum reagent. In the presence of Pd(OAc)/XantPhos as a commercially available catalyst, [1,2,3]-benzotriazin-4(3)-ones underwent denitrogenative coupling with DABAL-Me to afford a wide array of -aryl amides derived from -methylated carboxylic acids. Under the same catalytic conditions, -ethylation of [1,2,3]-benzotriazin-4(3)-ones could also be achieved by using triethylaluminum.