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

Abstract

Chiral ferrocene derivatives possessing planar stereogenic unit are important as chiral catalysts or materials. The principled method to obtain 1,2-disubstituted planarly chiral ferrocenes was base-mediated ortho-metalation performed on a chiral ferrocene derivative, typically using organolithium bases. A multitude of chiral ligands and other useful compounds was synthesized using this methodology. Newer methodology employing transition-metal catalyzed C-H bond activation strategies complements ortho-metalation methods and affords access to different types of planar chiral ferrocene derivatives.

Secondary Cationic Interaction Driven Substrate Ligand Affinity for Pd(II)-Catalyzed Enantioselective C-H Activation of Ferrocenyl Amines

“…The secondary amines are difficult directing groups for C-H activation/functionalization by TM-catalysed (vide supra) and conventional ortho-lithiation routes. 16 Consequently, C-H activation/functionalization in ferrocenyl secondary amines has not been studied to date; nonetheless, secondary amines offer numerous opportunities for further transformations. Here, we present secondary interaction-driven NOBINAc ligand accelerated Pd II -catalyzed enantioselective C-H activation of ferrocenyl secondary amines.…”