19348-89-1Relevant academic research and scientific papers
Synthesis of α-aminophosphonates using solvate ionic liquids
Eyckens, Daniel J.,Henderson, Luke C.
, p. 27900 - 27904 (2017/07/07)
A range of α-aminophosphonates were accessed in high yields and very rapidly, using solvate ionic liquids as the reaction media. Reactions typically required less than 10 minutes to go to completion and precipitation of these products into water excludes the use of traditional work up procedures, giving the products in very high crude purity. Excellent functional group tolerance for both the aldehyde and amine reaction partners was observed, and a range of bis-aminophosphonates derived from aromatic diamines were also accessed in high yield and purity.
Zinc Di(l-prolinate)-Mediated Synthesis of α-Aminophosphonates under Mild Conditions
De Oliveira, Aline R.,Katla, Ramesh,Rocha, Mariana P. D.,Albuquerque, Tábata B.,Da Silva, Caren D. G.,Kupfer, Vicente L.,Rinaldi, Andrelson W.,Domingues, Nelson Luís Campos
, p. 4489 - 4494 (2016/12/16)
An efficient method has been developed for the preparation of α-aminophosphonates by using zinc di(l-prolinate) as a catalyst under mild reaction conditions. The method has the advantages of high yields, short reaction times, and easy workup conditions.
A new, efficient and recyclable [Ce(l-Pro)]2(Oxa) heterogeneous catalyst used in the Kabachnik-Fields reaction
Da Silva, Caren D. G.,Oliveira, Aline R.,Rocha, Mariana P. D.,Katla, Ramesh,Botero, Eriton Rodrigo,Da Silva, érica C.,Domingues, Nelson Luís C.
, p. 27213 - 27219 (2016/03/25)
Herein we introduce a new catalyst for the Kabachnik-Fields reaction, [Ce(l-Pro)]2(Oxa), using a very accessible, simple and efficient methodology for α-aminophosphonate synthesis using an aromatic aldehyde, an aromatic amine and diphenyl phosphite. This procedure was developed using a low catalyst loading of cerium(iii) prolinate and it has allowed for the recycling of the catalyst.
Torsionally and Hydrophobically Modified 2,3-Diarylindenes as Estrogen Receptor Ligands
Anstead, Gregory M.,Peterson, Chad S.,Pinney, Kevin G.,Wilson, Scott R.,Katzenellenbogen, John A.
, p. 2726 - 2734 (2007/10/02)
2,3-Diarylindenes are ligands for the estrogen receptor which display intrinsic fluorescence.In order to optimize the receptor binding affinity of these compounds while preserving their desirable fluorescence properties, a series of torsionally modified analogues were prepared.A fluorine or methyl group was introduced on either of the two phenyl substituents ortho to their attachment site to the indene nucleus, in order to increase the out-of-plane twist of the appended rings.The analogues were prepared by the benzylation of appropriate deoxybenzoins, followed by Friedel-Crafts cyclic alkylation-dehydration.Comparison of the X-ray crystal structure of one analogue with unsubstituted analogues confirms the torsional perturbation effected by the ortho substituent.The torsional disposition of the C-2 aryl group in the substituted diphenylindenes is further investigated by UV (absorbance maxima and molar absorptivities), fluorescence (Stokes' shift), and NMR (chemical shifts).These spectroscopic measurements indicate increasing twisting between the C-2 aryl substituent and the indene system according to the following order: 3-ring o-Me-indene 9f diphenylindene 15 = 20 deg 3-ring o-F-indene 9c 1-Me-indene 16 2-ring o-F-indene 9b 2-ring o-Me-indene 9e = 63 deg.The binding affinity of these analogues to the estrogen receptor was evaluated by a competitive radiometric receptor binding assay.While o-fluoro or o-methyl substitution on the 3-ring increases binding only slightly, binding of the o-fluoro 2-ring analogue is increased ca. 6-fold and the o-methyl analogue 11-fold, giving, in the latter case, a compound with an affinity equivalent to that of estradiol.The increase in binding affinity afforded by ortho substitution correlates with the increase in the torsion angle of the C-2 aryl ring.A thermodynamic evaluation of the receptor fit (Andrews, P.R.; Craik, D.J.; Martin, J.L.J.Med.Chem. 1984, 27, 1648) indicates that, for the o-methyl-2-ring analogue, the effect of the ortho substitution on increasing receptor binding appears to be a combination of increased surface area due to the substituent itself, together with a change in surface area of the ligand that results from the increased torsion of the two aryl rings.An o-fluoro substituent on the 2-ring provides a compromise between the relative planarity required for high fluorescence intensity and the molecular shape needed for increased estrogen receptor binding affinity. o-Methyl, o-fluoro, and p-methyl substitution of the 3-ring have no value in the development of a fluorescent, higher affinity 2,3-diarylindene.
Design of Integrated Fluorescent Estrogens: The Second Donor Effect on Absorption, Fluorescence, and Ground-State Molecular Orbital Properties of trans-4,4'-Methoxynitrostilbene Systems
Anstead, Gregory M.,Katzenellenbogen, John A.
, p. 1328 - 1334 (2007/10/02)
In the design of inherently fluorescent ligands for the estrogen receptor, biological constraints limit to hydroxyl the functional groups that can be utilized as electron donors.In an attempt to optimize the fluorescent properties of such probes, we have studied the effect that a second alkoxy donor has on the fluorescence properties of two systems, peripherally located in a nitro-substituted diarylindene, and centrally located in a nitrostilbene.The second donor causes bathochromic shift in the absorbance spectrum (stilbene greater than diarylindene); however, the Stokes shift and fluorescence solvatochromism are less in the dual donor systems compared to the corresponding monodonor system.The fluorescence solvatochromism is investigated by using a model for solvent dispersive and dipole interactions.The relevant parameters are evaluated as follows: molecular geometry is obtained from X-ray crystallography, molecular mechanics, or semiempirical MO methods; molecular volumes are determined by molecular graphics; ground-state dipole moments calculated by the AM1 method; the noncollinearity of the ground- and excited-state dipoles is considered.This analysis rationalizes the effect of the second donor on reducing the fluorescence solvatochromism and demonstrates that the magnitude of this reduction depends on the conjugative contact of the second donor, being greater in the stilbene system than the diarylindene.Such an approach may be useful in the design of other fluorescent spectroscopic probes.
SUBSTITUENT EFFECTS ON THE 31P, 13C, AND 1H NMR CHEMICAL SHIFTS OF SUBSTITUTED DIPHENYL 1-PHENYLAMINO-1-PHENYLMETHANEPHOSPHONATES AND THEIR ANIONS
Smith, Scott J.,Zimmer, Hans,Fluck, Ekkehard,Fischer, Peter
, p. 105 - 120 (2007/10/02)
For a series of thirty-five novel diphenyl 1-phenylamino-1-phenylmethanephosphonates, substituted in the meta and para positions on the anilino and/or aryl ring, 31P chemical shifts show a good linear correlation with Hammett ?n and Taft ?0 parameters, the 31P nucleus being better shielded in the case of electron withdrawing substituents.The same pattern is observed for the phosphonate anions, except when para phenyl substituents can interact with the phosphorus atom by direct resonance.This inverse relationship is due to a field effect of the substituent dipole which polarizes ?-electron clouds in the molecule.A corresponding shift in ?-electron density is likewise observed for 13C resonances of the two diastereotopic phenoxy groups, the phenylamino and phenyl moieties.Vicinal CH-NH coupling is shown to be dependent on the rate of NH proton exchange as influenced by resonance, temperature and solvent effects.
