- Wet and dry processes for the selective transformation of phosphonates to phosphonic acids catalyzed by br?nsted acids
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A "wet"process and two "dry"processes for converting phosphonate esters to phosphonic acids catalyzed by a Bronsted acid have been developed. Thus, in the presence of water, a range of alkyl-, alkenyl-, and aryl-substituted phosphonates can be generally hydrolyzed to the corresponding phosphonic acids in good yields catalyzed by trifluoromethyl sulfonic acid (TfOH) at 140 °C (the wet process). On the other hand, with specific substituents of the phosphonate esters, the conversion to the corresponding phosphonic acids can be achieved under milder conditions in the absence of water (the dry process). Thus, the conversion of dibenzyl phosphonates to the corresponding phosphonic acids took place smoothly at 80 °C in toluene or benzene in high yields. Moreover, selective conversion of benzyl phosphonates RP(O)(OR′)(OBn) to the corresponding mono phosphonic acids RP(O)(OR′)(OH) can also be achieved under the reaction conditions. The dealkylation via the generation of isobutene of ditert- butyl phosphonate, and the related catalysis by TfOH took place even at room temperature to give the corresponding phosphonic acids in good to high yields. Nafion also shows high catalytic activity for these reactions. By using Nafion as the catalyst, phosphonic acids could be easily prepared on a large scale via a simple process.
- Li, Chunya,Saga, Yuta,Onozawa, Shun-Ya,Kobayashi, Shu,Sato, Kazuhiko,Fukaya, Norihisa,Han, Li-Biao
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p. 14411 - 14419
(2020/12/29)
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- Phosphate management with small molecules
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This invention relates to methods and small molecules having a phosphate group that can be used to inhibit phosphate transport and to treat or prevent diseases that are related to disorders in the maintenance of normal serum phosphate levels.
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- Rh(I)-catalyzed enantioselective hydrogenation of α-substituted ethenylphosphonic acids
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A class of chiral Rh(I) catalysts containing monodentate phosphorous acid diesters tautomerized from the corresponding secondary phosphine oxides was discovered by serendipitous hydrolysis of phosphoramidite ligands. The evolved catalysts demonstrated unprecedented enantioselectivities (98-99% ee) and high catalytic activities (as low as 0.01 mol% catalyst loading) in asymmetric hydrogenations of a wide variety of α-aryl-/alkyl-substituted ethenylphosphonic acids, providing a facile approach to the corresponding enantiopure phosphonic acids with significant biological importance.
- Dong, Kaiwu,Wang, Zheng,Ding, Kuiling
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supporting information; experimental part
p. 12474 - 12477
(2012/09/05)
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- Enantioselective synthesis of chiral α-aryl or α-alkyl substituted ethylphosphonates via Rh-catalyzed asymmetric hydrogenation with a P-stereogenic BoPhoz-type ligand
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(Chemical Equation Presented) An enantioselective synthesis of optically active 1-aryl or 1-alkyl substituted ethylphosphonates, based on the first Rh-catalyzed asymmetric hydrogenation of corresponding α,β- unsaturated precursors with a P-stereogenic BoPhoz-type ligand under the mild condition, was developed, in which a wide range of 1-aryl or 1-alkyl substituted ethylphosphonates were achieved in up to 98% ee.
- Wang, Dao-Yong,Hu, Xiang-Ping,Deng, Jun,Yu, Sai-Bo,Duan, Zheng-Chao,Zheng, Zhuo
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supporting information; experimental part
p. 4408 - 4410
(2009/09/08)
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- Synthesis of biologically active 1-arylethylphosphonates
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A convenient and inexpensive general preparation method for 1-arylethylphosphonic acids and their esters was developed involving in reduction of the corresponding 1-ethenylphosphonates by ammonium formate in the presence of palladium on carbon. A homogeneous enantioselective hydrogenation of 1-arylethenylphosphonic acids in the presence of chiral ruthenium catalysts provided optically active 1-arylethylphosphonic acids of enantiomeric purity up to 86%. The preliminary data on biological activity testing of the 1-arylethylphosphoic acids synthesized evidence that some among the compounds obtained are low-toxic substances with the properties of immunosuppressors of the central type of action.
- Gulyukina,Dolgina,Bondarenko,Beletskaya,Bondarenko,Henry,Lavergne,Ratovelomanana-Vidal,Genet
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p. 573 - 587
(2007/10/03)
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- A practical synthetic approach to chiral α-aryl substituted ethylphosphonates
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A convenient general method is reported for the synthesis of α-aryl substituted ethylphosphonic acids and esters by hydrogenation of α-aryl substituted ethenylphosphonic acids and esters. Racemic α-arylethylphosphonic acids and esters were prepared in 70-88% yield under palladium-assisted transfer hydrogenation conditions using ammonium formate. Asymmetric hydrogenation of α-arylethenylphosphonic acids using chiral Ru(II) catalysts led to α-arylethylphosphonic acids with enantiomeric excesses up to 86%.
- Goulioukina, Natalia S.,Dolgina, Tat'yana M.,Beletskaya, Irina P.,Henry, Jean-Christophe,Lavergne, Damien,Ratovelomanana-Vidal, Virginie,Genet, Jean-Pierre
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p. 319 - 327
(2007/10/03)
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- Asymmetric hydrogenation of vinylphosphonic acids and esters with chiral Ru(II) catalysts
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The first asymmetric hydrogenation of vinylphosphonic acids and esters to the corresponding arylethylphosphonic acids and esters using chiral Ru(II) catalysts is reported with enantiomeric excesses up to 86%.
- Henry,Lavergne,Ratovelomanana-Vidal,Genet,Beletskaya,Dolgina
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p. 3473 - 3476
(2007/10/03)
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- Phosphorylation of Acetophenone with Phosphorus Trichloride
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The mechanism of acetophenone phosphorylation with phosphorus trichloride to give 1-hydroxy-1-phenylethylphosphonic acid is discussed.A new procedure for synthesizing 1-phenylvinylphosphonic acid by dehydration of 1-hydroxy-1-phenylethylphosphonic acid in the presence of iodine is proposed.
- Khalmukhamedova, M. V.,Agzamov, T. A.,Alovitdinov, A. B.
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p. 360 - 362
(2007/10/03)
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- Formation of 1-phenylvinyl-1-phosphonic acid
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A process for forming 1-phenylvinyl-1-phosphonic acid utilizes reacting a mixture of phosphorus trihalide, such as phosphorus trichloride, and acetophenone with water, under conditions in which the water is gradually added to the mixture with cooling to form a reaction mixture, which can be sparged of excess acetophenone with aqueous acid while under vacuum, comprising the 1-phenylvinyl-1-phosphonic acid. This product can be recovered from the reaction mixture by recrystallization from aqueous mineral acid, such as hydrochloric acid.
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