Improved Palladium Catalysis in Suzuki‐Type Coupling of Benzotriazinones for <i>o</i>‐Aryl/Alkenyl Benzamides
Minling Xü, Ke Xü, Gang Zou
Abstract
Abstract A palladium catalyst system based on PdCl 2 (PPh 3 ) 2 or PdCl 2 (dppf) is reported for Suzuki‐type coupling of both N ‐aryl and alkyl benzotriazinones with aryl/alkenyl boronic acids to afford a series of ortho ‐aryl/alkenyl benzamides in yields up to 99%, showing improvements on catalytic efficiency, substrate scope and practicality. Scope and limitations of the improved protocol have been demonstrated with more than 40 examples, including a multigram‐scale synthesis of activated o ‐biphenyl amide. Large electronic and steric effects from the boronic acid counterpart have been observed, implying the transmetallation from boron to palladium should be involved in the rate‐determining step in catalytic cycle.