Broader, Greener, and More Efficient: Recent Advances in Asymmetric Transfer Hydrogenation

Asymmetric transfer hydrogenation has become a practically useful tool in reduction chemistry in the last decade or so. This was largely triggered by the seminal work of Noyori and co-workers in the mid-1990s and is driven by its complementing chemistry to hydrogenation employing H-2. This Focus Review attempts to present a holistic overview on the advances in the area, focusing on the achievements recorded around the last three years. These include more-efficient and greener metal catalysts, catalysts that enable hydrogenation as well as transfer hydrogenation, biomimetic and organocatalysts, and their applications in the reduction of C=O, C=N, and C=C bonds. Also highlighted are efforts in the development of environmentally benign and reusable catalytic systems.