Asymmetric hydrogenation of (E)-dimethyl-2-acetamido-2-phenylvinylphosphonate in supercritical carbon dioxide in the presence of metal complex catalysts with phosphite-type ligands

Asymmetric Hydrogenation of α‐ and β‐Enamido Phosphonates: Rhodium(I)/Monodentate Phosphoramidite Catalyst

“…[3a, 7] Specifically, catalytic AH of b-enamido phosphonates remains less explored despite some notable achievements made very recently for the AH of b-aryl-substituted b-enamido phosphonates by using rhodium-or iridium/diphosphine catalysts. [8][9][10] It seems somewhat surprising that to date no successful use of readily available monodentate chiral phosphine ligands in the Rh I -catalyzed AH of a-or b-enamido phosphonates has been achieved, despite the great successes in the AH of their dehydroamino acid analogues. [11] Apart from easy preparation and good stability, an important advantage of using monodentate phosphine ligands is that they may allow the use of ligand mixtures for rapid generation of a chiral catalyst library and hence high-throughput screening for a targeted reaction.…”

Asymmetric Hydrogenation of α‐ and β‐Enamido Phosphonates: Rhodium(I)/Monodentate Phosphoramidite Catalyst

“…6 In contrast, catalytic asymmetric protocols that can provide direct access to β‐amino phosphonic acid derivatives are remarkably scarce 3a. 7 Specifically, catalytic AH of β‐enamido phosphonates remains less explored despite some notable achievements made very recently for the AH of β‐aryl‐substituted β‐enamido phosphonates by using rhodium‐ or iridium/diphosphine catalysts 8–10. It seems somewhat surprising that to date no successful use of readily available monodentate chiral phosphine ligands in the Rh I ‐catalyzed AH of α‐ or β‐enamido phosphonates has been achieved, despite the great successes in the AH of their dehydroamino acid analogues 11.…”

Rh-catalyzed asymmetric hydrogenation of α- and β-enamido phosphonates: highly enantioselective access to amino phosphonic acids

“…Since 1985, the preparation of α- or β-phosphoramidates has been achieved by AH reactions with catalytic systems of chiral bisphosphine ligands and transition metals such as Ru, Rh and Ir (Scheme 1b, eqn (1)). 8 As hybrid bisphosphine ligands, chiral phosphine-phosphites have been applied for the hydrogenation of β-enamido phosphonates. 8 n Furthermore, in 2011, for the first time, Ding et al implemented the simultaneous AH reactions of α- and β-enamido phosphonates with rhodium and monodentate phosphoramidite ligands (DpenPhos) with high yield and high enantioselectivity.…”