Transfer Hydrogenation in Water: Enantioselective, Catalytic Reduction of (<i>E</i>)-β,β-Disubstituted Nitroalkenes
作者:Omid Soltani、Martin A. Ariger、Erick M. Carreira
DOI:10.1021/ol901332e
日期:2009.9.17
A mild catalytic asymmetric transfer hydrogenation of β,β-disubstitutednitroalkenes is reported. Formic acid is used as a reductant in combination with an Ir catalyst. The reaction is conducted in water at low pH and open to air to give adducts in preparatively useful yield and selectivity.
Go catalytic! A highlyenantioselectivehydrogenation of β,β‐disubstituted nitroalkenes and isomeric mixtures of nitroalkenes by using a Rh/DuanPhos catalytic system under basic conditions has furnished a convenient approach to β‐chiral nitroalkanes, which are otherwise not so easy to make (see scheme).
novel chiral bisphosphine-thiourea ligand was developed and applied in the highly enantioselective hydrogenation of β,β-disubstitutednitroalkenes (up to 99% yield and 99% ee). With low catalytic loading (0.25 mol %), 98% ee and 98% conversion were obtained. The thiourea group takes on an important role in this catalytic system.