From Mono-

Functionalization of carbon-hydrogen (C-H) bonds has emerged as a powerful strategy in modern organic synthesis, offering efficient routes to build molecular complexity from simple and abundant substrates. Among various transition-metal catalysts, palladium(II) complexes have proven particularly versatile for C-H activation, owing to the diverse reactivity of carbon-palladium bonds. To advance this approach, the discovery of ligands that can accelerate C-H activation as well as subsequent steps in the catalytic cycle is the pivotal driving force. While ligand development has long been integral to Pd(0) catalysts for activating electrophiles, notably in cross-coupling and asymmetric catalysis, the most common electron-donating ligands often inhibit Pd(II)-catalyzed C-H activation, as an electrophilic palladium center is often preferred. Hence the discovery of a suitable concerted metalation-deprotonation (CMD) motif that can be incorporated into bidentate ligands is critical. This design concept led us to discover a series of highly reactive bifunctional ligands that enhance reactivity and control site-selectivity as well as enantioselectivity.In 2008, our laboratory introduced the first bifunctional mono-