Mild and Homogeneous Cobalt-Catalyzed Hydrogenation of C=C, C=O, and C=N Bonds

摘要

The replacement of precious-metal catalysts with cheap and abundant metals is a major goal of sustainable chemistry. Hydrogenation catalysts have diverse and widespread applications, including the production of biorenewable chemicals and fuels, commodity chemicals, and the synthesis of fine chemicals and pharmaceuticals.Homogeneous rhodium, ruthenium, and iridium catalysts are also of critical importance in asymmetric hydrogenation. Despite significant recent advances, the design of earth-abundant-metal hydrogenation catalysts has lagged behind, perhaps because of the tendency of 3d metals to engage in one-electron or radical chemistry. Several iron catalysts have been developed for the hydrogenation of ketones or alkenes, but they are typically chemoselective, reducing only one class of substrate.'6"91 Furthermore, iron catalysts are often quite sensitive to additional oxygen- and nitrogen-containing functional groups and water.