Recent Developments in Palladium-Catalyzed Coupling Reactions

Abstract

During the last few years major advances in Pd-catalyzed coupling reactions have been described; new catalyst systems based on bulky, electron-rich phosphines have been developed. This short report focuses on the recent progress in this area. Palladium-catalyzed cross-coupling reactions have become one of the most powerful carbon-carbon and carbon- heteroatom bond forming reactions and have been widely employed in total synthesis (1). Whereas a wide range of aryl and vinyl halides with main group organometallic derivatives can be used in the Suzuki-Miyaura and Negishi reactions, few examples were reported with sterically hindered aryl halides and alkyl halides that possess β - hydrogen atoms, the problem with the latter being fast β- hydride elimination after oxidative addition to palladium (Scheme 1). Recent improvements in this field are the result of the development of new ligands such as bulky, electron- rich phosphines (2). This report proposes a short, non exhaustive overview of the recent progress in this area.