1538-69-8Relevant articles and documents
Bismuth(III)-Catalyzed Sequential Enamine-Imine Tautomerism/2-Aza-Cope Rearrangement of Stable β-Enaminophosphonates: One-Pot Synthesis of β-Aminophosphonates
Jin, Ming,Yin, Shi-Fu,Yang, Shang-Dong
, p. 2811 - 2815 (2020)
A novel catalytic tautomeric transformation of a β-enaminophosphoryl and 2-aza-Cope rearrangement sequence has been successfully applied to the one-pot synthesis of β-aminophosphonates with high efficiency and good tolerance. In this tandem reaction, Bi(OTf)3 exhibits unique activities and promotes both of enamine-imine tautomerism and 2-aza-Cope rearrangement.
Microwave michaelis-becker synthesis of diethyl phosphonates, tetraethyl diphosphonates, and their total or partial dealkylation
Meziane, Dalila,Hardouin, Julie,Elias, Abdelhamid,Guenin, Erwann,Lecouvey, Marc
, p. 369 - 377 (2009)
Diethyl phosphonates and tetraethyl alkyldiphosphonates were efficiently and rapidly prepared via the Michaelis-Becker reaction, under microwave irradiation. These compounds were then hydrolyzed to phosphonic and diphosphonic acids or selectively monodealkylated to give monoesters of phosphonic acids and symmetrical diethyl esters of diphosphonic acids. These reactions were also achieved rapidly in satisfactory yields with microwave methodology. This methodology was applied with success to the functionalization of a polymer resin.
CARBANIONS PHOSPHONATES α-LITHIES: SYNTHESE, BASICITE COMPAREE ET STABILITE A L'AUTOCONDENSATION
Teulade, Marie-Paule,Savignac, Philippe,Aboujaoude, Elie Elia,Collignon, Noel
, p. 283 - 296 (1986)
Non stabilized α-lithio-α-substituted alkanephosphonates (RO)2P(O)CHR1Li(R1 = H, alkyl, Cl) are commonly used as phosphonoalkylating agents.The strength of the conjugated acids (RO)2P(O)CH2R1 is estimated by concurrent metallation.The data checked range from phenylacetylene to toluene in relation with the inductive electronic effects of R and R1.Most of the α-phosphonyl carbanions give stable dimers via thermal self-condensation which is steric (R) and electronic (R1) effects dependent.In addition preparative conditions for some phosphonate precursors are reexamined.
Heck Reaction of Electronically Diverse Tertiary Alkyl Halides
Kurandina, Daria,Rivas, Mónica,Radzhabov, Maxim,Gevorgyan, Vladimir
supporting information, p. 357 - 360 (2018/01/27)
The efficient Pd-catalyzed Heck reaction of diverse tertiary alkyl halides with alkenes has been developed. Unactivated tertiary alkyl halides efficiently react at room temperature under visible light irradiation with no exogenous photosensitizers required. For activated tertiary alkyl halides, the same catalytic system works well without light. These methods offer a general access to electronically diverse alkenes possessing quaternary and functionalized tertiary allylic carbon centers. The substituents at these centers include alkyl-, carbalkoxy-, tosyl-, phosphonyl-, and boronate groups. It was also shown that the end-game mechanism of this transformation may vary depending on the type of the substrates used.
GOLD COMPOUNDS AND THEIR USE IN THERAPY
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Page/Page column 170, (2019/01/05)
Compound of formula (I) and pharmaceutically acceptable salts and solvates thereof are described, wherein: Px selected from (P1), (P2) or (P3); The compounds are useful in the prevention or treatment of a bacterial infection.
Surface-mediated solid phase reactions: A simple, efficient and base-free synthesis of phosphonates and phosphates on Al2O3
Acharya, Jyotiranjan,Shakya, Purushottam D.,Pardasani, Deepak,Palit, Meehir,Dubey, Devendra K.,Gupta, Arvind K.
, p. 194 - 196 (2007/10/03)
Al2O3-supported solvent free condensation of alkylphosphonic dichlorides with alcohols at room temperature yielded phosphorus esters in excellent yields.
Convenient one pot synthesis of phosphonites and H-phosphinates
Petnehazy, Imre,Jaszay, Zsuzsa M.,Szabo, Andrea,Everaert, Kinga
, p. 1665 - 1674 (2007/10/03)
A convenient and simple one-pot method is described for the synthesis of phosphonites [RP(OEt)2, 1] and H-phosphinates [HP(O)R(OEt), 2] from triethyl phosphite and appropriate Grignard reagents.
Fluorinated phosphorus compounds: Part 2. The synthesis of some bis(fluoroalkyl) alkylphosphonates
Timperley, Christopher M.,Broderick, John F.,Holden, Ian,Morton, Ian J.,Waters, Matthew J.
, p. 43 - 52 (2007/10/03)
Twenty bis(fluoroalkyl) alkylphosphonates of structure (RFO)2P(O)R were prepared in 28-69% yields by treatment of alkylphosphonic dichlorides Cl2P(O)R [R=Me, Et, n-Pr, i-Pr] with fluoroalcohols RFOH [RF=CF3CH2, H(CF2)2CH2, C2F5CH2, C3H7CH2, (CF3)2CH] in diethyl ether in the presence of triethylamine. Reactions of isopropylphosphonic dichloride with two molar equivalents of alcohols and fluoroalcohols were compared. After 12h at room temperature, the alcohols EtOH, n-PrOH, i-PrOH and n-BuOH gave mixtures of monoesters and diesters, except isopropanol, which gave the monoester exclusively. Electronic and steric effects caused by the alkoxy substituents satisfactorily account for the product ratios. With the fluoroalcohols CF3CH2OH, C2F5CH2OH, C3F7CH2OH and (CF3)2CHOH, the diesters predominated. Here the electronic effects of the fluoroalkoxy substituents stabilise the intermediate phosphoranes, eg. Cl2(RFO)P(OH)i-Pr and Cl(RFO)2P(OH)i-Pr, and drive the reactions to completion. Steric effects are clearly much less important in the case of attack by fluorinated alcohols.
Free radical desulfenylation and deselenylation of α-sulfur and α-seleno substituted phosphonates with the n-Bu3SnH/AIBN reagents system.
Balczewski,Piotr
, p. 113 - 122 (2007/10/03)
Selestive desulfenylation and deselenylation of α-sulfur- and α-seleno-substituted phosphonates under free radical condition are described.Chemoselectivity and scope of title reaction were studied using phosphonates additionaly functionalized in the α-position alkyl, phenyl,ethoxy,chloro,carbonyl and sulfenyl groups.It was found the reduction of a halogen tolerates the presence of the sulfenyl group and the latter could be reduced in the presence of the sulfinyl and sulfonyl moieties.Moreover,one sulfenyl group was selectively removed from α-phosphoryl dithioacetals and the phenylsulphenyl group was reduced preferentially in the presence of the methylsulfenyl one. Key words:Desulfenylation,deselenylation,α-phosphoryl sulfides,α-phosphoryl selenides, tri-n-butyltinhydride,α,α-azaisobutyronitrile.
Phosphate-phosphonate conversion: a versatile route to linear or branched alkylphosphonates
Patois, C.,Savignac, P.
, p. 630 - 635 (2007/10/02)
Addition of a symmetrically substituted trialkyl phosphate (R1O)3P(O) to a THF solution of an alkyllithium R2-CH2Li (2 equiv) at -78 deg C, followed by warming to room temperature, results in the quantitative formation of α-lithioalkylphosphonate.Treatment of the anion formed with aqueous HCl or an alkyl iodide yields the corresponding alkylphosphonate or α-substituted alkylphosphonate in good to excellent yields.Key Words: trialkyl phosphonates; alkyllithiums; α-lithioalkylphosphonates; alkylphosphonates.
