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

Abstract

We herein developed a palladium-catalyzed reaction of [1,2,3]-benzotriazin-4(3<i>H</i>)-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(3<i>H</i>)-ones underwent denitrogenative coupling with DABAL-Me₃ to afford a wide array of <i>N</i>-aryl amides derived from <i>ortho</i>-methylated carboxylic acids. Under the same catalytic conditions, <i>ortho</i>-ethylation of [1,2,3]-benzotriazin-4(3<i>H</i>)-ones could also be achieved by using triethylaluminum.