Homogeneously Catalyzed Aromatic Reduction

Cyclohexane derivatives, saturated cyclic compounds with a three-dimensional structure, are the fundamental and essential ingredients of various polymers and functional materials. Arene catalytic hydrogenations are straightforward and powerful transformation methods for valuable cycloalkane derivatives in the petroleum and fine chemical industries. Diastereoselective hydrogenation of arenes has especially garnered interest as an efficient method for accessing helpful building blocks, such as those utilized in drug discovery. Therefore, developing highly active catalysts for selective or asymmetric hydrogenation of arenes has attracted much attention as an important research area. An overview of homogeneous catalytic hydrogenation of aromatic nuclei in the past decade is described in this chapter. First, the difficulty in reducing aromatic rings and the practical usefulness of aromatic reduction are outlined. Then, various homogeneous catalytic reductions of aromatic nuclei are summarized by classifying the catalytic metal species: rhodium, ruthenium, chromium, cobalt, molybdenum, titanium, and alkaline earth metal. Finally, the conclusion and perspective are presented.