1445-75-6Relevant articles and documents
Structure and reactivity of mixed alkali metal alkoxide/aryloxide catalysts
Kissling,Gagne
, p. 9005 - 9010 (2001)
The average solution aggregation state of the ester interchange catalyst 1, obtained by mixing 1 equiv of NaOt-Bu and 3 equiv of NaOC6H4-4-t-Bu, was determined to be 4.0 by vapor pressure osmometry (VPO) in THF. Low-temperature 1H NMR spectra of 1 indicated that the THF solution contained a mixture of tetrameric clusters. On the basis of symmetry arguments and the sensitivity of the different species to the alkoxide/aryloxide ratio, the compounds were determined to be mixed clusters with 0:4, 1:3, 2:2, and 3:1 mixtures of the NaOt-Bu and NaOC6H4-4-t-Bu components. On a per -Ot-Bu basis, each cluster has a similar absolute activity, though the aryloxide-rich catalysts are significantly longer-lived. Unlike 1, catalysts containing ortho-substituted aryloxides, 2, do not give a strictly statistical distribution of clusters, and the activities of these catalysts depend on steric and electronic factors, though the absolute rate differences are not large.
Phase-transfer-catalyzed Michaelis-Becker synthesis of dialkyl methyl phosphonates
Fakhraian, Hossein,Mirzaei, Akbar
, p. 511 - 518 (2006)
A liquid-liquid phase-transfer-catalyzed (PTC) Michaelis-Becker reaction was adopted in the preparation of dialkyl methyl phosphonate (R=Me, iPr; nBu, and iBu). This was performed by the reaction of an appropriate dialkyl hydrogen phosphonate with methyl iodide in the presence of benzyl triethyl ammonium chloride and sodium hydroxide as PTC and base, respectively. A liquid-liquid two-phase system (H2O/CH2Cl2) introduced a suitable situation for the preparation of dialkyl methyl phosphonates with bulky alkyl groups (R=iPr, nBu, and iBu), but with R=Me, the hydrolysis of dimethyl hydrogen phosphonate (reagent) reduced the yield to 22%. In this case, a solid-liquid PTC-free system was successfully applied and yield of over 80% was obtained. Copyright Taylor & Francis Group, LLC.
Microwave-assisted ionic liquid-catalyzed selective monoesterification of alkylphosphonic acids—an experimental and a theoretical study
ábrányi-Balogh, Péter,Drahos, László,Harsági, Nikoletta,Henyecz, Réka,Keglevich, Gy?rgy
, (2021/09/07)
It is well-known that the P-acids including phosphonic acids resist undergoing direct es-terification. However, it was found that a series of alkylphoshonic acids could be involved in mo-noesterification with C2–C4 alcohols under microwave (MW) irradiation in the presence of [bmim][BF4] as an additive. The selectivity amounted to 80–98%, while the isolated yields fell in the range of 61–79%. The method developed is a green method for P-acid esterification. DFT calculations at the M062X/6–311+G (d,p) level of theory (performed considering the solvent effect of the corresponding alcohol) explored the three-step mechanism, and justified a higher enthalpy of activation (160.6–194.1 kJ·mol–1) that may be overcome only by MW irradiation. The major role of the [bmim][BF4] additive is to increase the absorption of MW energy. The specific chemical role of the [BF4] anion of the ionic liquid in an alternative mechanism was also raised by the computations.
Discovery of phosphonamidate IDO1 inhibitors for the treatment of non-small cell lung cancer
Du, Qianming,Feng, Xi,Wang, Yinuo,Xu, Xi,Zhang, Yan,Qu, Xinliang,Li, Zhiyu,Bian, Jinlei
, (2019/08/26)
Targeting indoleamine 2,3-dioxygenase 1 (IDO1) has been identified as an attractive approach for the development of cancer immunotherapy. In this study, a series of phosphonamidate ester containing compounds were designed, synthesized and evaluated for their inhibitory activities against IDO1. Among them, compounds 16, 17, and 26 with good IDO1 inhibitory (HeLa IDO1 IC50 = 10–21 nM, hIDO1 IC50 = 78–121 nM) activities were selected for further investigation and showed good physicochemical properties. Furthermore, based on comparable PK profile and excellent IDO2/TDO inhibitory potency, representative compound 16 was selected for further bio-evaluation and characterized with good efficacy in suppressing lung metastasis (77% inhibition rate) of Lewis cells in vivo. Thus, compound 16 could be a potential and efficacious agent for further evaluation.
