Ethyl phosphonate

Phosphite (C2H50)2P0H, phosphonate (C2H50)2P(0)H, ethyl phosphonate (R0)2P(0)C2H5. 

CN [l-[[[(2-chloroethyl)nitrosoamino]carbonyl]amino]ethyl]phosphonic acid diethyl ester... 

Several acyl derivatives of (aminomethyl)-and (1-aminoethyl)-phosphonic acids, in the latter case including [L-l-([L-alanyl]amino)ethyl]phosphonic acid (alafosfalin), have been prepared in their various diastereoisomeric forms and the... 

Bis(hexoxy-ethyl)phosphonic acid, in liquid-liquid extraction, 9 41... 

When ethyl phosphonates are used, the imine can be selectively deprotected after alkylation by treatment with dilute mineral acid (e.g., 10% HQ), 36"40 and the esters removed subsequently (see Section 10.10.3). When tert-butyl phosphonates are used, imine and ester hydrolysis is accomplished simultaneously under these conditions. These mild hydrolysis conditions are preferable when synthesizing amino acids with functionalized side chains 40 ... 

The glycosphingolipids of marine invertebrates sometimes include groups unusual for this class of compound. Thus, in the glycolipids of gastropods, (2-aminoethyl)phosphonic and [2-(methylamino)ethyl]phosphonic groups... 

Reaction of enol ether 1 a with sodium methoxidc or ethoxide. or 1 b with sodium methoxide, gives ketene acetals, which rearrange in the presence of triethylamine to give esters 3.3 The phosphorus ylide trimethoxy[2,2,2-trilluoro-l-(trifluoromethyl)cthylidene]-A ,-phosphane f(CF3)2C = P(OMc),] rearranges readily to dimethyl f2.2,2-trifluoro-1-mcthyl-l-(trifluoro-mcthyi)ethyl]phosphonate [(CF,)2C(Me)PO(OMe)2] in a similar 1.3-shift.5-0... 

Aminoalkylphosphonic acids are analogues of natural a-aminocarboxylic acids and are designated by generally accepted three-letter abbreviations for the amino acid residue followed by a superscript P. For example, 1-aminoethylphosphonic acid, which is related to alanine, is abbreviated as Alap. Diphenyl [l-(benzyloxycarbonylamino)ethyl]phosphonate, is abbreviated as Z-Alap(OPh)2. The l-aminoalkylphosphonic acids have modest water solubility, which significantly increases in strong acidic and alkali solution. They are not soluble... 

Dimethyl S-[diethyl(11-methyl-2 1 -keto-21-methyl ami ne)-thioether]-1-ethyl phosphonate, A035... 

The first example of a catalytic asymmetric Horner-Wadsworth-Emmons reaction was recently reported by Arai et al. [78]. It is based on the use of a chiral quaternary ammonium salt as a phase-transfer catalyst, 78, derived from cinchonine. Catalytic amounts (20 mol%) of organocatalyst 78 were initially used in the Homer-Wadsworth-Emmons reaction of ketone 75a with a variety of phospho-nates as a model reaction. The condensation products of type 77 were obtained in widely varying yields (from 15 to 89%) and the enantioselectivity of the product was low to moderate (< 43%). Although yields were usually low for methyl and ethyl phosphonates the best enantioselectivity was observed for these substrates (43 and 38% ee, respectively). In contrast higher yields were obtained with phosphonates with sterically more demanding ester groups, e.g. tert-butyl, but ee values were much lower. An overview of this reaction and the effect of the ester functionality is given in Scheme 13.40. 

Hai, V.T., Bompeix, G., and RavisA, A. 1979. Rile due tris-O-ethyl-phosphonate d aluminium dans la stimulation des reactions de dAfense des tissus de tomate contre la Phytophthora capsici. C.R. Hebd. Seances Acd. Sci., Ser. D. 228, 1171-1174. 

The 1,3,2-oxazaphospholanes 90a-c and 91a-c were obtained in excellent yields by cyclization of the amino alcohols 89a -c with ethyl phosphonic dichloride in toluene in the presence of triethylamine. The mixture of diastereomers at the phosphorus center were separated by silica gel chromatography. Assignation of the absolute configurations was possible through a complete analysis of the H NMR spectra of the diastereomers and was confirmed by X-ray analysis for one derivate (Scheme 41). 

Another important source of chiral auxiliaries for the synthesis of optically active phosphorus derivates are the C2 symmetric diamines such as 1,2-diaminocyclohex-anes. In 1994, Hanessian and co-workers described the use of A,/V -dimethyl-(R,R)-1,2-diaminocyclohexane 93 as a chiral auxiliary in the synthesis of optically pure or enantiomerically enriched a-alkyl a-amino phosphonic acids [49], Starting from easily accessible optically pure diamine 93, they synthesized in good yield (75 %) enantiomerically pure (R,R)-ethylphosphonamide 94 by condensation with ethyl phosphonic dichloride in benzene in the presence of triethylamine (Scheme 43). 

SYNS DIETHYL (2-(METHYLDIETHOXYSILYL)-ETHYL)PHOSPHONATE PHOSPHONIC ACID, (2-(DIETHOXYMETHYLSILYL)ETHYL)-, DIETHYL ESTER SILANE 40-43... 

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