- A convenient two-step synthesis of dialkylphosphate ionic liquids
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Dialkylphosphate ionic liquids are useful solvents for cellulose dissolution and catalytic reactions. In this paper, a new methodology for the synthesis of hydrophobic phosphate-based ionic liquids is described. This method involves the oxidation reaction of an easily prepared H-phosphonate precursor by using the environmentally friendly and inexpensive oxidizing agent hydrogen peroxide.
- Kotlarska, Justyna,Binnemans, Koen,Dehaen, Wim
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- Method for preparing phosphite diester by transesterification
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The invention discloses a method for preparing phosphite diester by transesterification. Dimethyl phosphite and monohydric alcohol which are used as raw materials are stirred, reacted and rectified under the action of a basic catalyst to prepare the phosphite diester, so the problems of high deice requirements and large amount of acid-containing three wastes in the process of producing the phosphite diester by reacting phosphorus trichloride with alcohol are avoided. The method has the advantages of low raw material toxicity, simple process, mild reaction conditions, low device requirements, low pollution, high raw material conversion rate, high product selectivity, stable supply of the raw materials, provision of the phosphite diester used for fine chemical engineering or medical intermediates by dimethyl phosphite production enterprises, high added values of the product, and provision of a new way for the synthesis of the phosphite diester.
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Paragraph 0027
(2020/01/25)
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- Water determines the products: An unexpected Br?nsted acid-catalyzed PO-R cleavage of P(iii) esters selectively producing P(O)-H and P(O)-R compounds
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Water is found able to determine the selectivity of Br?nsted acid-catalyzed C-O cleavage reactions of trialkyl phosphites: with water, the reaction quickly takes place at room temperature to afford quantitative yields of H-phosphonates; without water, the reaction selectively affords alkylphosphonates in high yields, providing a novel halide-free alternative to the famous Michaelis-Arbuzov reaction. This method is general as it can be readily extended to phosphonites and phosphinites and a large scale reaction with much lower loading of the catalyst, enabling a simple, efficient, and practical preparation of the corresponding organophosphorus compounds. Experimental findings in control reactions and substrate extension as well as preliminary theoretical calculation of the possible transition states all suggest that the monomolecular mechanism is preferred.
- Li, Chunya,Wang, Qi,Zhang, Jian-Qiu,Ye, Jingjing,Xie, Ju,Xu, Qing,Han, Li-Biao
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supporting information
p. 2916 - 2922
(2019/06/18)
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- Synthesis of H-Phosphonate Intermediates and Their Use in Preparing the Herbicide Glyphosate
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The esterfication of hypophosphorous acid is followed by reaction with another molecule of alcohol under the action of a nickel catalyst to provide a green method for the preparation of H-phosphonate diesters. This method avoids the need for any stoichiometric chlorine unlike those based on phosphorous trichloride.
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Paragraph 0036; 0044; 0050
(2014/10/16)
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- Organophosphorus chemistry without PCl3: A bridge from hypophosphorous acid to H-phosphonate diesters
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A process for the conversion of hypophosphorous acid (H3PO 2, HPA) and alcohols into various H-phosphonate diesters [(RO) 2P(O)H] is described. The new reaction provides a missing bridge between HPA and important H-phosphonates, completely avoiding the use of PCl3. Nickel chloride or nickel on silica catalyze the oxidative phosphorylation of alkyl phosphinates with various alcohols or water. The reaction is atom economic and avoids the formation of waste products. The previous need for both chlorine and base is completely avoided. Esterification of hypophosphorous acid followed by reaction with another molecule of alcohol under the action of a nickel catalyst provides a green method for the preparation of H-phosphonates. This method entirely avoids the need for any stoichiometric chloride unlike those based on phosphorus trichloride. Copyright
- Fisher, Henry C.,Prost, Lucie,Montchamp, Jean-Luc
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p. 7973 - 7978
(2014/01/06)
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- Highly efficient asymmetric mannich reaction of dialkyl α-diazomethylphosphonates with N -carbamoyl imines catalyzed by chiral bronsted acids
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An efficient method involving the first use of chiral phosphoric acids as catalysts in the asymmetric Mannich reaction of dialkyl diazomethylphosphonates and N-carbamoyl imines is developed. With only 0.1 mol % catalyst 1f, the reaction proceeded smoothly and produced the corresponding β-amino-α- diazophosphonate with up to 97% yield and >99% ee.
- Zhang, Hui,Wen, Xiaojing,Gan, Lihua,Peng, Yungui
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supporting information; experimental part
p. 2126 - 2129
(2012/07/17)
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- Synthesis of O,O-dialkyl 2-oxo-2-(4-(selenomorpho-linosulfonyl)phenylamino) ethylphosphonate
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A series of O,O-dialkyl 2-oxo-2-(4-(seleomorpholinosulfonyl)phenylamino) ethy lphosphonate were synthesized by reactions of 2-chloro-N-(4- (seleomorpholino sulfonyl)phenyl)acetamide with dialkylphosphite in the presence of sodium hydride. The structure of all new compounds has been confirmed by 1H NMR,31P NMR, IR, Mass spectroscopy and elemental analyses. Copyright Taylor & Francis Group, LLC.
- Wang, Fang,Hu, Liming,Li, Xiaopeng,Xu, Xuemei,Du, Hongguang
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scheme or table
p. 610 - 616
(2009/04/11)
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- A novel short and efficient synthetic route to the antimalarial agent FR900098 and derivatives
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We report here a new operationally simple, economical, and environmentally friendly multicomponent approach for a one-pot synthesis of the antimalarial agent FR900098. The reaction allows the fast construction of the compound from simple and commercially available substrates and reagents and is also applicable to the synthesis of modified derivatives of FR900098. Georg Thieme Verlag Stuttgart.
- Perruchon, Johann,Ortmann, Regina,Schlitzer, Martin
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p. 3553 - 3557
(2008/09/19)
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- Method and compositions for identifying anti-HIV therapeutic compounds
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Methods are provided for identifying anti-HIV therapeutic compounds substituted with carboxyl ester or phosphonate ester groups. Libraries of such compounds are screened optionally using the novel enzyme GS-7340 Ester Hydrolase. Compositions and methods relating to GS-7340 Ester Hydrolase also are provided.
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- Method and compositions for identifying anti-HIV therapeutic compounds
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Methods are provided for identifying anti-HIV therapeutic compounds substituted with carboxyl ester or phosphonate ester groups. Libraries of such compounds are screened optionally using the novel enzyme GS-7340 Ester Hydrolase. Compositions and methods relating to GS-7340 Ester Hydrolase also are provided.
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- Prodrugs of Phosphonoformate: Products, Kinetics and Mechanisms of Hydrolysis of Dibenzyl (Methoxycarbonyl)phosphonate
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Dibenzyl (methoxycarbonyl)phosphonate (1) has been prepared by the reaction of benzyl alcohol with (methoxycarbonyl)phosphonic dichloride.The hydrolysis of 1 proceeded rapidly, with a half-life of 60 min at 36.4 deg C and pH 7.4, by two main pathways.The dominant pathway (k1, 6.56 * 10-3 min-1) yielded the diester, benzyl (methoxycarbonyl)phosphonate (2) and benzyl alcohol (3), with P-O cleavage.The second (k2, 3.55 * 10-3 min-1) gave dibenzyl phosphite (4), possibly arising from the hydrolysis of the carboxyl ester followed by decarboxylation.Benzyl phosphite (5) was also observed, which arises from the hydrolysis of 4 with P-O cleavage (k5, 9.04 * 10-4 min-1).Other products formed in small amounts were, benzyl (benzyloxycarbonyl)phosphonate (6) (k3, 3.59 * 10-4 min-1) and dibenzyl phosphate (7) (k4, 4.24 * 10-4 min-1).The rapid and complicated hydrolysis of 1, involving four competitive reactions, two of which involve C-P bond cleavage, suggests that triesters of phosphonoformate are unlikely to be suitable prodrug forms.
- Mitchell, Antony G.,Nicholls, Dave,Walker, Ian,Irwin, William J.,Freeman, Sally
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p. 1297 - 1304
(2007/10/02)
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