- Synthesis of γ-butyrolactones containing α,α-difluoromethylenyl bisphosphonate initiated by Na2S2O4
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Diethyl iododifluoromethylphosphonate (1) reacted with 4-pentenoic acids in the presence of Na2S2O4 in aqueous acetonitrile solution at ambient temperature to afford various γ-butyrolactones containing α,α-difluoromethylenyl bisphosphonate moiety in moderate to good yields.
- Yang, Xueyan,Zhu, Yaoping,Fang, Xiang,Yang, Xianjin,Wu, Fanhong,Shen, Yongjia
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Read Online
- Non-metallic compd. Bisphosphonic acid crosslinked layered manufacturing method
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PROBLEM TO BE SOLVED: To provide a novel noncrosslinking type layered phosphonic acid metal compound which has high crystallinity and a uniformly introduced multicomponent phosphonic acid and is free of a fluorine atom, and to provide a method for the production of the same.SOLUTION: The method for the production of the noncrosslinking type layered phosphonic acid metal compound includes a reaction step of reacting two or more monophosphonic acids or derivatives thereof having predetermined conditions with a metal source that can generate a hexacoordinated metal atom ion to be a central atom (M) of a metal oxide octahedron upon reaction in the presence of a sulfuric acid catalyst. The noncrosslinking type layered phosphonic acid metal compound obtained by the production method is also provided.
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Paragraph 0128; 0129
(2017/01/02)
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- Synthetic and mechanistic aspects of halo-F-methylphosphonates
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The synthesis of a variety of new halo-F-methylphosphonates has been achieved by a Michaelis-Arbuzov type reaction between a halo-F-methane and a trialkyl phosphite. This synthesis has proved to be of wide scope and utility for the high yield preparation of a number of heretofore unknown compounds. The 1H, 19F, 13C and 31P NMR spectroscopic properties are reported in detail. The mechanism for the formation of bromodifluoromethylphosphonates has been shown to proceed through the intermediacy of difluorocarbene:CF2. The phosphonate products have been shown to react with a wide variety of reagents. Fluoride and alkoxide ions react by attack at phosphorus with cleavage of the carbon-phosphorus bond and formation of [:CF2] from the bromodifluoromethylphosphonates and the CFBr2- anion from the dibromofluoromethylphosphonates. Iodide ion and tertiary phosphines react by attack at the ester carbon to give stable phosphonate salts. Hydrolysis of the phosphonate esters with 50% aqueous HCl gives the expected phosphonic acids. Trimethylsilyl bromide attacks phosphoryl oxygen to afford the bis(trimethylsilyl) esters.
- Flynn, Richard M.,Burton, Donald J.
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experimental part
p. 815 - 828
(2011/10/08)
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- Synthetic and mechanistic aspects of the reactions between bromodifluoromethyltriphenylphosphonium bromide and dibromofluoromethyltriphenylphosphonium bromide and trialkylphosphites
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Bromofluoromethyltriphenylphosphonium bromides react with trialkylphosphites in two distinct ways. Bromodifluoromethyltriphenylphosphonium bromide undergoes a rapid exchange reaction with trialkylphosphites to give the corresponding bromodifluoromethylphosphonates in good to excellent yields. A similar exchange reaction also occurred with an analogous diethoxyphenylphosphonite to give the corresponding ethoxyphenylphosphinate. Mechanistically, the exchange process involves the formation of difluorocarbene via dissociation of the intermediate difluoromethylene ylide, capture of the difluorocarbene by the trialkylphosphite to give [ (RO)3 over(P, +) C over(F2, -) ], which captures bromine followed by dealkylation to the product, bromodifluoromethylphosphonate. The equilibria involved in the multi-step mechanism are all shifted to the phosphonate product by the final dealkylation step. In contrast, the dibromofluoromethyltriphenylphosphonium bromide does not under exchange reactions with trialkylphosphite. The phosphite serves as a halophilic reagent to abstract Br from the dibromofluoromethylphosphonium salt to generate the bromofluoromethylene ylide, which can easily be trapped in situ with aldehydes or ketones to give good yields of the E/Z-bromofluoroalkenes. No dissociation of the bromofluoromethylene ylide was observed.
- Flynn, Richard M.,Burton, Donald J.,Wiemers, Denise M.
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p. 583 - 589
(2008/12/22)
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- 2-IMIDAZOLONE AND 2-IMIDAZOLIDINONE HETEROCYCLIC INHIBITORS OF TYROSINE PHOSPHATASES
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Compounds and compositions are provided for modulating the activity of protein tyrosine phosphatases. The compounds for use in the compositions and methods provided herein have formulae (I) Protein tyrosine hosaphatase, including PTB-1B, mediated diseases and disorders include diabetes including Type 1 and Type 2 diabetes (and associated complications such as hypertension, ischemic diseases of the large and small blood vessels, blindness, circulatory problems, kidney failure and atherosclerosis), syndrome X, methabolic syndrome, glucose intolerance, insulin resistance, obesity, cancer, neurodegenerative diseases.
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Page/Page column 64-65
(2008/06/13)
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- TYROSINE PHOSPHATASE SCAFOLD SYNTHESIS
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Disclosed are 4-(difluoromethylene)phosphonate cinnamic acid derivatives as a molecular scaffold for the preparation of protein tyrosine phosphatase inhibitors. The invention also relates to a process for the combinatorial preparation of protein tyrosine phospatase inhibitors possessing a 4-(difluoromethylene)phosphonate cinnamic acid/ester molecular scaffold
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- A useful magnesium reagent for the preparation of 1,1-difluoro-2-hydroxyphosphonates from diethyl bromodifluoromethylphosphonate via a metal-halogen exchange reaction
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When (EtO)2P(O)CF2Br (1) is treated with isopropylmagnesium chloride in THF at low temperature it gives a magnesium species (2) which undergoes reactions with strong electrophiles (HCl, TMSCl, halogens, aldehydes and ketones). The formation of products depends strongly on the reaction conditions. With 1.5 equivalents of 2 between - 78 and 0°C, a conversion of more than 90% of aldehydes and ketones into 2-hydroxyphosphonates (7 and 8) can be achieved. These compounds (7 and 8) in the presence of base (NaH, LDA) are rearranged into 2,2-difluoroethylphosphates without concomitant formation of 1,1-difluoroolefines.
- Waschbuesch, Rachel,Samadi, Mohammad,Savignac, Philippe
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p. 267 - 278
(2007/10/03)
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- Preparation and synthetic application of diethyl 2-oxo-1,1-difluorophosphonates
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Reaction of diethyl(bromodifluoromethyl)phosphonate (EtO)2P(O)CF2Br 1 with activated zinc gave [(diethoxyphosphonyl)difluoromethyl]zinc bromide (EtO)2P(O)CF2ZnBr 2, which was acylated with various acylating agents to afford diethyl 2-oxo-1,1-difluorophosphonates (EtO)2P(O)CF2C(O)R 4 in good yields. Treatment of phosphonates 4 such as diethyl 2-oxo-1,1-difluoropropylphosphonate (EtO)2P(O)CF2C(O)CH3 4a, ethyl difluoro(diethoxyphosphonyl)pyruvate (EtO)2P(O)CF2C(O)CO2Et 4e and N,N-diethyldifluoro(diethoxyphosphonyl)acetamide (EtO)2P(O)CF2C(O)NEt2 4h with Grignard reagents R'MgX provided 1,1-difluoroolefins R′(CH3)C=CF2, R′(CO2Et)C=CF2 and R′(NEt2) C=CF2, respectively.
- Tsai, Hou-Jen
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p. 247 - 259
(2007/10/03)
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- Synthesis and NMDA receptor binding of 2-amino-7,7-difluoro-7-phosphonoheptanoic acid
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In an NMDA specific receptor binding assay, 1 had lower affinity than its parent, APH. This result suggests that for competitive antagonists, diionization of the phosphonic acid moiety may be detrimental to receptor affinity.
- Bigge,Drummond,Johnson
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p. 7013 - 7016
(2007/10/02)
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- FLUORINE IN ENZYME CHEMISTRY: PART 1. SYNTHESIS OF DIFLUOROMETHYLENEPHOSPHONATE DERIVATIVES AS PHOSPHATE MIMICS
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Diethyl difluoromethylphosphonylcadmium bromide reacts with allyl and benzyl halides in THF to give the corresponding difluoromethylenephosphonate derivatives.The reaction with allyl bromide affords a versatile synthetic intermediate which undergoes a variety of synthetic transformations and therefore becomes a key compound in the preparation of elaborated difluoromethylenephosphonates of biological significance.
- Chambers, R. D.,Jaouhari, R.,O'Hagan, D.
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p. 275 - 284
(2007/10/02)
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- Preparation of Difluorophosphonoacetic Acid and Its Derivatives
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The preparation of ethyl difluoro(diethoxyphosphinyl)acetate (1) has been effected by the acylation of zinc bromide with ethyl chloroformate in the presence of a catalytic amount of cuprous bromide.Similarly prepared were ethyl difluoro(diethoxyphosphinyl)pyruvate (2) and N,N-diethyldifluoro(diethoxyphosphinyl)acetamide (3).Bromotrimethylsilane selectively reacted with 1 to yield ethyl difluoroacetate (9).The remaining ethyl carboxylic ester of 9 reacted with iodotrimethylsilane to produce trimethylsilyl difluoroacetate (10), which was subsequently hydrolyzed to yield difluorophosphonoacetic acid (8).The phosphonate 9 was gently chlorinated to yield ethyl difluoro(dichlorophosphinyl)acetate (11).
- Burton, Donald J.,Sprague, Lee G.
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p. 1523 - 1527
(2007/10/02)
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- Phosphorylation of Isoprenoid Alcohols
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Procedures for the synthesis and purification of 20 isoprenoid diphosphates and methanediphosphonate analogues from the corresponding alcohols are described.The alcohols are activated for phosphorylation by conversion of homoallylic systems to tosylates and allylic systems to halides.The activated intermediates are treated with tris(tetra-n-butylammonium) salts of pyrophosphoric, methanediphosphonic, or difluoromethanediphosphonic acid to obtain the corresponding esters in yields 34-80percent.Chromatography on cellulose is a general method for purification of isoprenoid diphosphates, and procedures are decribed for compounds with C5 to C20 hydrocarbon moieties.The displacement by pyrophosphate occurs with inversion of configuration, and the procedure can be used to prepare isoprenoid diphosphates with chiral C1 methylene groups in high optical purity from the corresponding alcohols.
- Davisson, V. Jo,Woodside, Andrew B.,Neal, Timothy R.,Stremler, Kay E.,Muehlbacher, Manfred,Poulter, C. Dale
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p. 4768 - 4779
(2007/10/02)
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- Phosphine- and Phosphite-Mediated Difluorocarbene Exchange Reactions of (Bromodifluoromethyl)phosphonium Salts. Evidence for Facile Dissociation of (Difluoromethylene)triphenylphosphorane
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(Bromodifluoromethyl)triphenylphosphonium bromide undergoes facile exchange of the bromodifluoromethyl group with tertiary phosphine and trialkyl phosphite.A mechanism that involves formation of the difluoromethylene ylide and dissociation of the ylide into difluorocarbene and triphenylphosphine is proposed to account for the observed exchange process.
- Burton, Donald J.,Naae, Douglas, G.,Flynn, Richard M.,Smart, Bruce E.,Brittelli, David R.
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p. 3616 - 3618
(2007/10/02)
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- A USEFUL ZINC REAGENT FOR THE PREPARATION OF 2-OXO-1,1-DIFLUOROALKYLPHOSPHONATES
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The treatment of dialkyl bromodifluoromethylphosphonates with activated zinc dust in various solvents gave dialkoxyphosphinyldifluoromethylzinc compounds 2, which were acylated with acid halides or fluorinated acid anhydride to afford dialkyl 2-oxo-1,1-difluoroalkylphosphonates in good yields.
- Burton, Donald J.,Ishihara, Takashi,Maruta, Masamichi
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p. 755 - 758
(2007/10/02)
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- Preparation, Stability, Reactivity and Synthetic Utility of a Cadmium Stabilized Complex of Difluoromethylene Phosphonic Acid Ester
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Diethyl bromodifluoromethylphosphonate reacts readily with cadmium metal to form a stable cadmium complex.Depending on solvent, this functionalized organocadmium reagent exhibits stability for days to months.It reacts with a variety of electrophiles and serves as a synthetically useful source for the introduction of the difluoromethylene phosphonate group into organic compounds.
- Burton, Donald J.,Takei, Ryutaro,Shin-Ya, Seiji
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p. 197 - 202
(2007/10/02)
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