Advances and challenges in palladium-catalyzed intermolecular selective allylic C-H functionalization of alkenes

During the past decade, there was increased interest in the functionalization of the allylic C-H bond of alkenes. As opposed to traditional Trost-Tsuji reactions, this strategy avoids the prefunctionalization of the alkene. Many transi- tion metals have been used to promote such processes, and palladium has proved to be one of the best catalysts as it offers great advantages from the point of view of substrate scope and selectivity. Therefore, many groundbreaking re- suits obtained with Pd-catalyzed processes have been re- ported, including allylic C-H oxygenation, amination, al- kylation, and other transformations, which have been well documented in reviews [1].