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.

B2(OH)4-Mediated Reductive Transamidation of N-Acyl Benzotriazoles with Nitro Compounds En Route to Aqueous Amide Synthesis.

We herein developed a reductive transamidation reaction between N-acyl benzotriazoles (AcBt) and organic nitro compounds or NaNO2 under mild conditions. This protocol employed the stable and readily available B2(OH)4 as the reducing agent and H2O as the ideal solvent. N-Deuterated amides can be synthesized when conducting the reaction in D2O. A reasonable reaction mechanism involving bond metathesis between the AcBt amide and amino boric acid intermediate was proposed to explain the unique nature of AcBt.