Enantioselective Synthesis of α-Hydroxy and α-Amino Phosphonates via Catalytic Asymmetric Hydrogenation
摘要:
[GRAPHICS]Cationic rhodium catalysts of the C-2 symmetric DuPHOS (1) and BPE (2) ligands have demonstrated the ability to asymmetrically hydrogenate a novel series of enol phosphonates (3) in good to excellent enantiomeric excess under mild conditions. Initial studies toward the catalytic asymmetric hydrogenation of enamido phosphonates (6 and 7) using the DuPHOS-Rh+ catalysts are also reported.
Highly Enantioselective Synthesis of α-Hydroxy Phosphonic Acid Derivatives by Rh-Catalyzed Asymmetric Hydrogenation with Phosphine–Phosphoramidite Ligands
作者:Kamyar Afarinkia、Juan Echenique、Stanley C. Nyburg
DOI:10.1016/s0040-4039(97)00157-3
日期:1997.3
A number of alpha-ketophosphonate are prepared and shown to he easily enolised. An X-ray crystal structure determination of a beta-phenyl-alpha-ketophosphonate shows the molecule to be present as hydrogen bonded dimers and demonstrates the presence of enol tautomer in solid state. alpha-ketophosphonate can be converted to the corresponding enolacetate under mild conditions. The enolacetate have the E-configuration exclusively. (C) 1997 Elsevier Science Ltd.
Organocatalyzed asymmetric Michael reaction of β-aryl-α-ketophosphonates and nitroalkenes
作者:Jie Guang、John Cong-Gui Zhao
DOI:10.1016/j.tetlet.2013.08.015
日期:2013.10
The first enantioselective Michael reaction of beta-aryl-alpha-ketophosphonates and nitroalkenes has been realized by using a new bifunctional Takemoto-type thiourea catalyst. The primary Michael adducts obtained were converted in situ to the corresponding amides through the aminolysis. High yields, excellent diaste-reoselectivities (>95:5 dr), and good enantioselectivities (up to 81% ee) have been achieved for the corresponding oc,13-disubstituted gamma-nitroamides. This reaction again demonstrated that alpha-ketophosphonates are interesting pronucleophiles that can be used as amide surrogates in organocatalyzed reactions. (C) 2013 Elsevier Ltd. All rights reserved.
Asymmetric hydrogenation of α- or β-acyloxy α,β-unsaturated phosphonates catalyzed by a Rh(i) complex of monodentate phosphoramidite
The Rh(I) complex of a monodentate phosphoramidite bearing a primary amine moiety (DpenPhos) has been disclosed to be highly efficient for the asymmetric hydrogenation of a variety of α- or β-acyloxyα,β-unsaturatedphosphonates, providing the corresponding biologically important chiral α- or β-hydroxy phosphonic acid derivatives with excellent enantioselectivities (90–>99% ee).
Enantioselective Synthesis of α-Hydroxy and α-Amino Phosphonates via Catalytic Asymmetric Hydrogenation
作者:Mark J. Burk、Timothy A. Stammers、Judith A. Straub
DOI:10.1021/ol9906099
日期:1999.8.1
[GRAPHICS]Cationic rhodium catalysts of the C-2 symmetric DuPHOS (1) and BPE (2) ligands have demonstrated the ability to asymmetrically hydrogenate a novel series of enol phosphonates (3) in good to excellent enantiomeric excess under mild conditions. Initial studies toward the catalytic asymmetric hydrogenation of enamido phosphonates (6 and 7) using the DuPHOS-Rh+ catalysts are also reported.