Highly stereo- and regiocontrolled cyclopentannulation via allylphosphonate conjugate addition and hydroboration-oxidation-elimination. Synthesis of pentalenic acid with virtually complete stereo- and regiocontrol
Dynamic Kinetic Resolution Based Asymmetric Transfer Hydrogenation of α-Alkoxy-β-Ketophosphonates. Diastereo- and Enantioselective Synthesis of Monoprotected 1,2-Dihydroxyphosphonates
作者:Se-Mi Son、Hyeon-Kyu Lee
DOI:10.1021/jo500148j
日期:2014.3.21
Dynamic kinetic resolution driven, asymmetric transfer hydrogenation reactions of a wide range of 2-substituted α-alkoxy-β-ketophosphonates 3 were observed to proceed efficiently to give the corresponding 2-substituted α-alkoxy-β-hydroxy phosphonates 4 with excellent levels of diastereo- and enantioselectivity. These processes are promoted by using well-defined, commercially available, chiral transition
A Novel Approach to γ-Hydroxy-α,β-unsaturated
Compounds
作者:Henryk Krawczyk、Katarzyna Wąsek、Jacek Kędzia
DOI:10.1055/s-0028-1083162
日期:——
A simple synthesis of (E)-alk-1-enyl mesylates from (E)-alk-1-enylphosphonates is reported. Construction of γ-hydroxy-α,β-unsaturated compounds was achieved by a two-step process involving dihydroxylation of the enol mesylates followed by HWE reaction of the resulting α-hydroxy aldehydes with activated methylphosphonates. Enantioselective synthesis of the title compounds is also reported.
Phosphonate vs. phosphinate elimination during olefination of aldehydes
作者:Mahavir Prashad
DOI:10.1016/0040-4039(93)85013-m
日期:1993.3
Olefination of aldehydes with O,O,O-triethyl methylmethylenephosphonophosphinate in the presence of magnesiumbromideetherate and triethylamine leads to a selective elimination of the phosphonate group over the phosphinate to yield alkenyl(methyl)phosphinates in a convenient manner.
Synthesis of α-Aminophosphonates by Umpolung-Enabled Cu-Catalyzed Regioselective Hydroamination
作者:Shogo Nakamura、Soshi Nishino、Koji Hirano
DOI:10.1021/acs.joc.2c02632
日期:2023.1.20
A copper-catalyzed regioselective hydroamination of α,β-unsaturated phosphonates has been developed to form corresponding α-aminophosphonates of interest in medicinal chemistry. The introduction of an umpolung, electrophilic amination strategy with the hydroxylamine derivative is the key to achieving the α-amination regioselectivity, which is otherwise difficult under the conventional nucleophilic