Synthesis of ortho-Methylated Benzamides via Palladium-Catalyzed Denitrogenative Cross-Coupling Reaction of [1,2,3]-Benzotriazin-4(3H)-ones with DABAL-Me3.

We herein developed a palladium-catalyzed reaction of [1,2,3]-benzotriazin-4(3H)-ones with DABAL-Me3 [bis(trimethylaluminum)-1,4-diazabicyclo[2.2.2]octane adduct], a cheap, stable, and solid organoaluminum reagent. In the presence of Pd(OAc)2/XantPhos as a commercially available catalyst, [1,2,3]-benzotriazin-4(3H)-ones underwent denitrogenative coupling with DABAL-Me3 to afford a wide array of N-aryl amides derived from ortho-methylated carboxylic acids. Under the same catalytic conditions, ortho-ethylation of [1,2,3]-benzotriazin-4(3H)-ones could also be achieved by using triethylaluminum.