5954-28-9Relevant academic research and scientific papers
Asymmetric hydrogenation of α- Or β-acyloxy α,β- unsaturated phosphonates catalyzed by a Rh(i) complex of monodentate phosphoramidite
Zhang, Jinzhu,Dong, Kaiwu,Wang, Zheng,Ding, Kuiling
supporting information; scheme or table, p. 1598 - 1601 (2012/03/22)
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-acyloxy α,β- unsaturated phosphonates, providing the corresponding biologically important chiral α- or β-hydroxy phosphonic acid derivatives with excellent enantioselectivities (90->99% ee).
Making mixtures to solve structures: structural elucidation via combinatorial synthesis
Lengkeek, Nigel A.,Greenwood, Paul F.,Nguyen, Blake,Koutsantonis, George A.,Piggott, Matthew J.
scheme or table, p. 141 - 150 (2010/10/19)
A domino Horner-Wadsworth-Emmons olefination strategy has been used to prepare homologous series of (polyen)ones, and through combinatorial elaboration, corresponding families of highly branched hydrocarbons. Gas chromatography-mass spectrometry of the mixtures has enabled the rapid and unambiguous identification of several highly branched alkanes of geochemical importance. This is the first example of the use of combinatorial synthesis for the elucidation of structural connectivity.
An efficient separation method for enol phosphate and corresponding β-ketophosphonate from their mixtures under aqueous conditions
Moorhoff, Cornelis M.
, p. 2069 - 2086 (2007/10/03)
Separation of a mixture β-ketophosphonate 3 and their corresponding enol phosphate 4 is efficiently carried out in aqueous alkaline solutions. Enol phosphate 4 is first extracted with hexanes:dichloromethane (19:1). Acidification of the aqueous layer followed by extraction of the β-ketophosphonate 3 with dichloromethane completes the separation. Thus, when 1-bromo-2,4-pentadione la reacted with triethyl phosphite to give diethyl (2,4-dioxopentyl)phosphonate 3a (Arbuzov-product) and the corresponding enol phosphate 4a (Perkow-product), separation of the two compounds was carried out using this method.
Comparative spectroscopic and theoretical studies on the conformation of some α-diethoxyphosphoryl carbonyl compounds and their α-ethylsulfonyl analogues
Olivato, Paulo R.
, p. 97 - 102 (2007/10/03)
Comparative vco IR analysis of β-carbonylphosphonates [XC(O)CH2P(O)(OR)2: X = Me 1, Ph 2, OEt 3, NEt2 4 and SEt 5; R = Et] (series I) and β-carbonylsulfones [XC(O)CH2SO2R: X = Me 6, Ph 7, OEt 8, NEt2 9 and SEt 10; R = Et] (series II) along with ab initio 6-31 G** calculations on la and 6a (R = Me) suggest the existence of only a single gauche conformer for series I. The negative carbonyl frequency shifts for both series follow approximately the electron-affinities of the π*co orbital of the parent compounds MeC(O)X 11-15. The less positive asymmetric sulfonyl frequency shifts (ΔvSO2) for II in relation to the phosphoryl frequency shifts (ΔvPO) for I and the larger negative carbonyl frequency shifts for II with respect to the corresponding values for I are in line with the upfield 13C NMR chemical shifts of the carbonyl carbon for II compared to I. These trends agree with the shorter O(SO2) ...C(CO) contact in comparison with the O(PO) ... C(CO) one and are discussed in terms of Olp→π*co charge transfer and electrostatic interactions, which are stronger for series II than for I, indicating that the sulfonyl oxygen atom is a better electron donor than the phosphoryl oxygen atom. Intrinsic geometrical parameters of O=S-CH2 and O=P-CH2 moieties seem to be responsible for this behaviour as indicated by X-ray study and ab initio calculations of dialkyl (methylsulfonyl)methylphosphonate MeSO2CH2P(O)(OR)2(R = Et l8, Me 18a). The Royal Society of Chemistry 2001.
Silyl Phosphites. 15. Reactions of Silyl Phosphites with α-Halo Carbonyl Compounds. Elucidation of the Mechanism of the Perkow Reaction and Related Reactions with Confirmed Experiments
Sekine, Mitsuo,Okimoto, Kiyomi,Yamada, Khoji,Hata, Tsujiaki
, p. 2097 - 2107 (2007/10/02)
The reactions of silyl phosphites, i.e., tris(trimethylsilyl)phosphite (1), diethyl trimethylsilyl phosphite (11), and bis(trimethylsilyl) ethyl phosphite (12), with a variety of α-halo carbonyl compounds gave the 1:1 carbonyl addition products (6, 13, and 14), enol phosphates (5 and 26), and/or 2-oxophosphonates (4 and 25).Substituents on the phosphites and the α-halo carbonyl compounds have influenced the product ratios.The results of these reactions strongly suggest that the Perkow reaction proceeds via an initial attack of phosphite on the carbonyl carbon of the α-halo carbonyl compound.Treatment of bis(trimethylsilyl) 1--2-halo phosphonates (6) with sodium methoxide in methanol followed by retrimethylsilylation gave bis(trimethylsilyl) 1,2-epoxy phosphonates (17), bis(trimethylsilyl) 2-oxo phosphonates (4), and bis(trimethylsilyl) methyl phosphate (21).On the other hand, diethyl 1-hydroxy-2-halo phosphonates (22) were converted by treatment with different bases to 1,2-epoxy phosphonates (23) predominantly in good yields.When some of tri-n-butyltin alkoxides were used as bases, enol phosphates (26) were obtained selectively.Several bis(trimethylsilyl) esters obtained in the above reactions were successfully converted to the corresponding monoanilinium salts in high yields by treatment with aniline-containing alcohols.
