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-Me<sub>3</sub>
Shangzhang Li, Yang Li, Riqian Zhu, Jin Bai, Yue Shen, Mengni Pan, Wanfang Li
Abstract
We herein developed a palladium-catalyzed reaction of [1,2,3]-benzotriazin-4(3 H )-ones with DABAL-Me 3 [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 H )-ones underwent denitrogenative coupling with DABAL-Me 3 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(3 H )-ones could also be achieved by using triethylaluminum.
Topics & Concepts
ChemistryXantphosCatalysisPalladiumReagentAdductOctaneArylMedicinal chemistryCoupling reactionOrganic chemistryCombinatorial chemistryAlkylCatalytic C–H Functionalization MethodsPhenothiazines and Benzothiazines Synthesis and ActivitiesCatalytic Cross-Coupling Reactions