- A Convenient Synthesis of Diethyl 1-Chloroalkylphosphonates
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The title compounds were obtained in high yield by the reaction of diethyl 1-hydroxyalkylphosphonates with triphenylphosphine carbon tetrachloride.
- Gajda, Tadeusz
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- Direct and straightforward transfer of C1 functionalized synthons to phosphorous electrophiles for accessinggem-P-containing methanes
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The direct transfer of different α-substituted methyllithium reagents to chlorinated phosphorous electrophiles of diverse oxidation state (phosphates, phosphine oxides and phosphines) is proposed as an effective strategy to synthesize geminal P-containing
- Touqeer, Saad,Ielo, Laura,Miele, Margherita,Urban, Ernst,Holzer, Wolfgang,Pace, Vittorio
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supporting information
p. 2425 - 2429
(2021/04/02)
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- SYNTHESIS OF INTERMEDIATES USED IN THE MANUFACTURE OF ANTI-HIV AGENTS
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The present invention relates to a process of preparing intermediates of Formula (I). The process comprises of reacting compound of Formula (III) with compound of Formula (V) in the presence of a solvent selected from an alcohol, ether or water to form compound of Formula (I) wherein, R1 is selected from –NH2, Cl, Br, NHCOR", wherein R" is alkyl, aryl, Schiff's base of formula N=CHR', wherein R' is alkyl or aryl; R2 is selected from H, alkyl; R3 and R4, each independently is H; R5 and R6, each independently is H, alkyl; R7 is H, alkyl; and R8 is H, alkyl.
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Page/Page column 25-26
(2016/11/21)
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- Dynamic kinetic resolution of α-chloro β-keto esters and phosphonates: Hemisynthesis of Taxotere through Ru-DIFLUORPHOS asymmetric hydrogenation
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The dynamic kinetic resolution (DKR) of racemic α-chloro β-ketoesters and α-chloro β-ketophosphonates through ruthenium-mediated asymmetric hydrogenation is reported. The corresponding α-chloro β-hydroxyesters and α-chloro β- hydroxyphosphonates were obtained in good to high enantio- and diastereomeric excesses using, in particular, the atropisomeric ligand DIFLUORPHOS. This methodology allowed an efficient preparation of the anti phenylisoserine side chain of Taxotere which has been used for the hemisynthesis of the cancer therapeutic agent itself. In addition, 13C NMR in chiral oriented solvents was used to investigate the DKR effect.
- Prevost, Sebastien,Gauthier, Sebastien,De Andrade, Maria Cristina Cano,Mordant, Celine,Touati, Ali Rhida,Lesot, Philippe,Savignac, Philippe,Ayad, Tahar,Phansavath, Phannarath,Ratovelomanana-Vidal, Virginie,Genet, Jean-Pierre
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experimental part
p. 1436 - 1446
(2010/11/03)
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- Reactions of α-boranophosphorus compounds with electrophiles: Alkylation, acylation, and other reactions
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(Chemical Equation Presented) The homologation of phosphorus carbenoids with organoboranes leads to α-boranophosphorus compounds, which can be further functionalized through reactions with various electrophiles, either directly or after activation to the
- Antczak, Monika I.,Montchamp, Jean-Luc
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supporting information; experimental part
p. 3758 - 3766
(2009/11/30)
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- Mild synthesis of organophosphorus compounds: Reaction of phosphorus-containing carbenoids with organoboranes
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Organoboranes react with phosphorus-containing carbenoids to produce a variety of functionalized organophosphorus compounds under mild conditions. In some cases, selective migration of one group atached to boron can be observed. Phosphonite-borane complexes are introduced as novel synthons for the synthesis of phosphinic esters.
- Antczak, Monika I.,Montchamp, Jean-Luc
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supporting information; experimental part
p. 977 - 980
(2009/04/10)
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- Synthesis, reactivity and stereochemistry of new phosphorus heterocycles with 5- or 6-membered rings
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Syntheses of novel phosphorus heterocycles containing α-amino or α-hydroxyphosphonic or phosphinic acids motifs are developed. 2,3-dihydro-1,3-oxaphospholes (1) and 1,4,2-oxazaphosphinanes (2) exhibit a reactive part, respectively the enolether moiety and the P-H bond, which allows various structural modifications: (i) for 1a, by introduction of amino substituents, (ii) for 2a, by hydroxy- or aminoalkylation, by Michael addition or by P-arylation. These reactions present generally a good or even an excellent kinetic diastereoselectivity which can often be predicted by molecular models of the transition states.
- Cristau, Henri-Jean,Pirat, Jean-Luc,Virieux, David,Monbrun, Jér?me,Ciptadi, Ciptadi,Bekro, Yves-Alain
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p. 2472 - 2481
(2007/10/03)
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- New route to aminomethylphosphonic acid via bis(trifluoroethyl) phosphonate transesterification
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Transesterification of bis(trifluoroethyl) chloromethyl- and azidomethyl-phosphonates with alcohols in the presence of catalytic quantities of alcoholates gives dialkyl chloromethyl- and azidomethyl-phosphonates in good yield.This process has been used fo
- Berte-Verrando, Sylvie,Diziere, Rachel,Samadi, Mohammad,Savignac, Philippe
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p. 3125 - 3128
(2007/10/03)
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- PREPARATION DE L'ACIDE AMINOMETHYLPHOSPHONIQUE α-DIDEUTERIE
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Nucleophilic amination of chloromethylphosphonic esters was studied, α-Dideuteriated aminomethylphosphonic acid was obtained from bis(trifluoroethyl) chloromethylphosphonic ester and sodium azide through substitution of the chlorine, reduction of the azide and acidic hydrolysis.Incorporation of the deuterium was greated than 95percent and overall yields were in the range 55-65percent. Key words: nucleophili amination, chloromethylphosphonic esters, α-dideuteriated chloromethylphosphonic esters, sodium azide, aminomethylphosphonic acid, deuterium oxide, trifluoroethanol d, α-dideuteriated aminomethylphosphonic acid.
- Berte-Verrando, Sylvie,Nief, Francois,Patois, Carl,Savignac, Philippe
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- Free radical reaction of α-haloalkylphosphonates with alkenes and alkynes: A new approach to modified phosphonates
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A new approach to the synthesis of phosphonates 3 functionalized in the α- and γ-phosphonate positions by alkyl, ethoxy, butoxy, acetoxy, acetyl and cyanide groups and allylphosphonate 6 is described. It is based on the radical reaction of α-halosubstituted phosphonates 1 (X = Cl, Br, I) with the terminally unsubstituted alkenes 2 (1-heptene, ethoxyethene, butoxyethene, acetoxyethene, acrylonitrile, methyl vinyl ketone) and alkyne 5 (hept-1-yne). The reaction involving the tin hydride method (Bu3SnH/AIBN) was more effective with alkenes than with alkynes (40-72% versus 20-30%). With electron-rich alkenes, chloro- and bromomethylphosphonates 1 (X = Cl, Br) gave higher yields than iodomethylphosphonate 1 (X = I). Diethyl methylphosphonate 4, as a reduction product of 1, accompanied 3 and 6 in the above reactions. The yield of 4 could be reduced by optimizing the reaction conditions.
- Balczewski,Mikolajczyk
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p. 392 - 396
(2007/10/02)
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- A Cheap One-Pot Approach to Tetraethyl Methylenediphosphonate
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A cheap procedure for the preparation of tetraethyl methylenediphosphonate is described.
- Hormi, Osmo E.O.,Pajunen, Esko O.,Avall, Ann-Kristin C.,Pennanen, Paivi
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p. 1865 - 1867
(2007/10/02)
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- Carbanions phosphonate prepares par voie electrochimique: formation et reactivite vis-a-vis d'un aldehyde
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Reactivity towards p-methoxybenzaldehyde (ArCHO) of electrochemically generated phosphonate carbanions has been investigated.Electrolyses were carried out at a mercury cathode in DMF and two routes to the desired carbanion have been compared: (i) Deprotonation of phosphonates of general formula (EtO)2P(O)CHYW (Y = W = Cl; Y = H, W = Cl; Y = Cl, W = CO2Et; Y = H, W = CO2Et; Y = CH3, W = CO2Et; Y = Cl, W = CH3), by the bases resulting from the electroreduction of azobenzene; addition of the carbanion formed onto the carbonyl group takes place and leads to the adduct (EtO)2P(O)CYW(Ar)O-. (ii) Two-electron reduction of halophosphonates (EtO)2P(O)CXYW (X = Cl, Y and W as above; X = Br, W = CO2Et, Y = Cl, Br, or CH3); when no H atom is present on the carbon bearing the phosphonate group (Y and W no = H), the same evolution leading to the above adduct is observed, on the contrary, when Y = H, the electrogenerated carbanion deprotonates the substrate and the resulting carbanion (EtO)2P(O)CXW reacts with the aldehyde; giving the adduct (EtO)2P(O)CXW(Ar)O-.Evolution of the intermediate adduct depends on the substituents Y (or X) and W: when W = CO2Et, whatever the nature of Y (or X), diethyl phosphate is eliminated with formation of the ethylenic ArCH=CWY (or X) (Wittig-Horner reaction); the same evolution is observed when Y = W = Cl.When W = Cl and Y = H or CH3, the final product is the phosphonate epoxyde resulting from chloride elimination (Darzens reaction).Chemo- and stereoselectivity depend only on the nature of Y and W but are independent of the mode of generation of the carbanion.Yields are limited by side-protonation reactions, which are related to the basicity of the phosphonate carbanions.Analysis of the results permits selection of the optimal electrolysis conditions for purposes of synthesis.Key words: electrosynthesis, electrogenerated bases, phosphonates, Wittig-Horner.
- Le Menn, Jean-Christophe,Sarrazin, Jean,Tallec, Andre
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p. 1332 - 1343
(2007/10/02)
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- Le O,O-diethyltrimethylsilylchloromethylphosphonate α-lithie (C2H5O)2P(O)C(Cl)Si(CH3)3Li
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Silylation of either chloromethyl- or trichloromethyl-phosphonate in the presence of excess n-BuLi leads to the quantitative generation of lithiated trimethylsilylchloromethylphosphonates.This stable type of anion can be protonated, deuterated or alkylate
- Teulade, Marie-Paule,Savignac, Philippe
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p. 295 - 304
(2007/10/02)
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- PREPARATION ELECTROCHIMIQUE DES CHLOROMETHYL ET DICHLOROMETHYL-PHOSPHONATES DE DIETHYLE
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Diethylchloromethyl and dichloromethyl-phosphonates are easily prepared by electrochemical reduction of diethyltrichloromethylphosphonate in alcoholic acetate solutions at a graphite electrode under galvanostatic conditions.
- Tue Bi, Balo,Devaud, Marguerite
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p. 3799 - 3800
(2007/10/02)
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- The electrochemical Wittig-Horner reaction; evidence of a stepwise cleavage of a four-membered ring Wittig intermediate
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Electro-reduction of diethyl(trichloromethyl)phosphonate in the presence of aldehydes or ketones relpaces the oxygen atom of the carbonyl group by a dichloromethylene group.The yield of 1,1-dichloroethene product decreases subtantially if the carbonyl com
- Tilborg, W. J. M. van,Smit, C. J.
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p. 202 - 206
(2007/10/02)
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