Palladium catalysis enables cross-coupling–like SN2-glycosylation of phenols

Editor’s summaryGlycosylations are an important feature of many natural products, but methods to install sugars can suffer from limitations on stereospecificity because many reactions proceed through an oxocarbenium intermediate in which stereochemistry is lost. Deng et al. developed a versatile palladium-catalyzed reaction for the glycosylation of phenols that resembles palladium-catalyzed aryl carbon–oxygen cross-coupling reactions. Palladium oxidative addition to an easily prepared ortho-iodobiphenyl S-glycoside yields a complex that reacts with a wide range of phenolates through a SN2 mechanism to afford the glycosylated phenols with inversion of stereochemistry. This reaction works well with, but it is not limited to, 2-deoxy sugars and can be performed in one pot with other palladium-catalyzed cross-couplings to yield complex O-glycosides. —Michael A. Funk