Earth-Abundant Metal-Catalyzed Asymmetric Hydrogenation of Carbon-Nitrogen Unsaturated Bonds
Chenguang Liu, Qiang Liu
Abstract
Asymmetric hydrogenation of carbon-nitrogen unsaturated bonds is an effective method for the construction of chiral amines. However, most of the known examples rely on the use of noble metal (ruthenium, rhodium, iridium, palladium, etc.) catalysts. Therefore, the replacement of noble-metals by earth-abundant and biocompatible first-row transition metals (manganese, iron, cobalt, nickel, etc.) for the development of new catalysts in asymmetric hydrogenation reactions is of great significance towards sustainable synthesis of chiral nitrongen-containing fine chemicals. In recent years, earth-abundant metal catalyzed asymmetric hydrogenation of unsaturated bonds has witnessed significant progress and shown broad prospects for its applications. Considering that the structures and properties of different earth-abundant metal catalysts have remarkable influence on the reactivity, selectivity, and substrate generality of the target transformations, this review provides an overview of earth-abundant metal catalyzed asymmetric hydrogenation of carbon-nitrogen unsaturated bonds categorized according to the types of central metals in catalysts.