Asymmetric Transfer Hydrogenation of β-Nitroacrylates

Significance

List and co-workers report a new approach to enantiopure β^²-amino acids. The key step of their synthesis is a Jacobsen-type thiourea-1-catalyzed conjugate reduction of β-nitroacrylates to the corresponding β-nitroesters. This reaction works well with a variety of substrates. ­Although the described reaction is not stereo-convergent, stereoconvergence can be established by adding catalytic amounts of triphenyl­phosphine. In addition, a new and facile synthesis of β-nitroacrylates was developed.