Comparison of Diastereoselective ortho-Metalations and C–H ­Activations of Chiral Ferrocenes

Abstract Chiral ferrocene derivatives possessing a planar stereogenic unit are important as chiral catalysts and materials. The principle method to obtain 1,2-disubstituted planarly chiral ferrocenes is base-mediated ortho-metalation performed on a chiral ferrocene derivative, typically using organolithium bases. A multitude of chiral ligands and other useful compounds have been synthesized by using this methodology. Newer methodologies employing transition-metal-catalyzed C–H bond activation strategies complement ortho-metalation methods and affords access to different types of planar chiral ferrocene derivatives. 1 Introduction 2 Base-Mediated ortho-Deprotonations 3 Diastereoselective C–H Activations 4 Examples of Enantioselective C–H Activations 5 Conclusions