Enantioselective Synthesis of Chiral Phosphonates via Rh/f-spiroPhos Catalyzed Asymmetric Hydrogenation of β,β-Disubstituted Unsaturated Phosphonates
The first asymmetric hydrogenation of β,β-diaryl unsaturated phosphonates has been realized for synthesis of β,β-diaryl chiral phosphonates with excellent enantioselectivities (up to 99.9% ee) catalyzed by the Rh-(R,R)-f-spiroPhos complex. Furthermore, this catalyst also exhibits comparably excellent performance for β-aryl-β-alkyl unsaturated phosphonates providing the corresponding chiral phosphonates with up to 99.9% ee values. This methodology provides a straightforward access to asymmetric synthesis of chiral phosphonates.
Facile and stereoselective synthesis of vinylphosphonates
Stereoselective syntheses of mono-, di- and trisubstituted diethyl alk-1-enylphosphonates, starting from readily available alk-1-ynylphosphonates, have been developed, using catalytic hydrogenation or cuprate addition on the triple bond.
A convenient stereoselective synthesis of disubstituted alk-1-enyl phosphonates
A stereoselective synthesis of disubstituted diethyl alk-1-enylphosphonates has been developed via syn addition of RMgX/CuCl to alk-1-inylphosphonates. Key words: Phosphonate; Stereoselective synthesis; Cuprate addition; Phosphorus