Studies On Transition-metals Palladium And Copper Catalyzed Decarboxylative Cross-coupling Reactions

The formation of new chemical bonds is a key transformation in organicsynthesis. In recent years, transition-metal-catalyzed cross-coupling reactions havefundamentally changed the strategies and become a rapidly growing area of research forcarbon–carbon and carbon–heteroatom bond formations. In this context, decarboxylativecross-coupling reactions have recently been considered in organic synthesis. For suchreactions use more stable and less expensive carboxylic acids (or their esters and salts) assubstrates comparing to traditional cross-coupling methods. Herein we also envisagedtransition-metal-catalyzed organic reactions by the study of transition-metal-catalyzeddecarboxylative cross-coupling reactions. The following contents were included:(1) CuBr2-catalyzed decarboxylative coupling reactions of α-oxocarboxylic acids withformamides: In the presence of CuBr2and tert-butyl peroxide as the oxidant includingtrimethyl acetic acid as an additive, can α-Oxocarboxylic acids react smoothly withformamides to generate the corresponding cross-coupling products in good to excellentyields. It is important to note that this is a very effective new method for α-amidecarbonyl compounds.(2) Palladium-catalyzed decarboxylative cross-coupling reactions of benzoyl peroxidewith acetanilides: Herein we report a new efficient palladium-catalyzed reaction ofbenzoyl peroxide with a wide range of acetanilides through a tandem C–H activationprocess through decarboxylative cross-coupling under mild reaction conditions by useof benzoyl peroxide to stripped CO2easily and become aryl radicals under heatingcondition.