Liu Jin-Kui, Gong Jun-Fang, Song Mao-Ping
College of Chemistry and Molecular Engineering, Henan Key Laboratory of Chemical Biology and Organic Chemistry, Zhengzhou University, Zhengzhou 450001, People's Republic of China.
Org Biomol Chem. 2019 Jun 26;17(25):6069-6098. doi: 10.1039/c9ob00401g.
Palladium pincer complexes, containing a monoanionic terdentate ligand composed of an anionic aryl carbon atom and two mutually compatible donor sites, have aroused considerable interest since their first reports in the late 1970s. The high stability of the Pd pincer complexes and particularly their high modularity make these species ideal candidates for catalysis. Furthermore, the nature of the meridional coordination of the pincer ligands, and along with this their ability to enforce a stereo-specific environment around the Pd center, provide a good opportunity for developing chiral Pd pincer catalysts. Thus, a broad variety of chiral Pd pincer complexes have been prepared by the introduction of various stereochemical centers in the pincer skeletons. These chiral Pd pincer complexes have been successfully applied to many asymmetric catalytic reactions such as hydrophosphination reactions, allylation of aldehydes and imines, Michael and aldol reactions, Suzuki-Miyaura reactions as well as reactions of nitrile compounds with imines. This review focuses on the synthetic methods and the applications of chiral Pd pincer complexes in asymmetric catalysis.
钯钳形配合物包含一个由阴离子芳基碳原子和两个相互兼容的供体位点组成的单阴离子三齿配体，自20世纪70年代末首次报道以来，引起了人们的广泛关注。钯钳形配合物的高稳定性，尤其是其高度模块化，使其成为催化的理想候选物。此外，钳形配体的经向配位性质以及随之而来的在钯中心周围形成立体特异性环境的能力，为开发手性钯钳形催化剂提供了良好机会。因此，通过在钳形骨架中引入各种立体化学中心，已制备了多种手性钯钳形配合物。这些手性钯钳形配合物已成功应用于许多不对称催化反应，如氢膦化反应、醛和亚胺的烯丙基化反应、迈克尔反应和羟醛反应、铃木-宫浦反应以及腈化合物与亚胺的反应。本综述重点介绍手性钯钳形配合物的合成方法及其在不对称催化中的应用。
