Chapter 3 - Chiral pincer complexes and their application to asymmetric synthesis

Abstract

Terdentate anionic chiral pincer complexes are obtained by the same techniques as their achiral counterparts and architectures incorporating a range of ligand and metal variations have been synthesized. These methods broadly fall into three main categories—namely, (1) Transmetallation, (2) Oxidative addition, (3) and Direct C−H activation. The suitability of each method strongly depends on the nature of the ligands and metals used. This chapter defines pincer complexes as containing anionic terdentate ligands with formal negative charges lying on the central atom attached to the metal. The focus is on the synthetic step—the chiral pincer construction step—that introduces a metal. Chiral and achiral nitrogens that contain pincer complexes are used in a wide range of applications that are not directly related to synthesis including small molecule sensing. NCN pincer complexes are divided then according to the nature of the nitrogens in the system. A comprehensive compendium of chiral pincer complexes and their synthesis is provided.