Tetraethyl pyrophosphite

S.P. solid-phase technique L.P. liquid-phase technique OPTcp pentachlorophenyl ester TEEP tetraethyl pyrophosphit OTCp trichlorophenyl ester ONp p-nitrophenyl ester ONSu N-hydroxysuccinimido ester OPFp pentafluorophenyl ester OQu 8-hydroxyquinyl ester OPy 3-hydroxy-pyridyl ester ODnp 2,4-dinitrophenyl ester DCC dicyclohexylcarbodiimide HOBn 3-hydroxy-4-oxo-3,4-dihydro-l,2,3-benzotriazin Opi JV-hy-droxypiperidine EEDQ 2-ethoxy-l-ethoxycarbonyl-l,2-dihydroquinoline Tos p-toluenesulfonyl PTC propanetricarboxylic acid OBu tm-butyl ester Nva norvaline Aha aminohexanoic acid Om ornithine... 

Prepared from catechol and phosphorus trichloride via o-phenylenephosphoro-chloridite. Used in peptide synthesis for the direct interaction of the two com-ponents (compare tetraethyl pyrophosphite). Synthesis of dipeptides is satisfactory, but extensive racemization occurs when N-acyl peptides are employed. 

Special solvent. Diethyl phosphonate is miscible with water and with ordinary organic solvents and has remarkable solvent power. It is recommended as solvent and acid-acceptor for peptide syntheses utilizing tetraethyl pyrophosphite" or a reagent such as ethyl dichlorophosphite. ... 

Coupling, active ester Bis-(2,4-dinitrophenyl)carbonate. Chloroacetonitrile. Di(p-nitrophenyl)carbonate. 2-Ethoxypyridine-l-oxide. p-Nitrobenzyl tosylate. p-Nitrophenol. p-Nitrophenyl trifluoroacetate. Pentachlorophenol. Phenyltrimethylammonium ethoxide. Phosgene. Pyrazole. Sulfur dioxide-Dimethylformamide. Tetraethyl pyrophosphite. N,N -Thionyldiimidazole. 2,4,S-Trichlorophenol. 

Reactions of Tetraethyl Pyrophosphite with Perfluoroalkyl Iodides and Subsequent Oxidation... 

The reaction of tetraethyl pyrophosphite with perfluoroalkyl iodides in the presence of di-tert-butyl peroxide in l,l,2-trichloro-l,2,2-trifluoroethane (1-113) was described for the first time in 1981 Thermal decomposition of di-tert-butyl peroxide leads to the abstraction of an iodine atom and gives the reactive perfluoroalkyl radical, which reacts with tetraethyl pyrophosphite to produce the perfluoroalkyl phosphonite. Subsequent oxidation with tert-butyl hydroperoxide provides the desiied perfluoroalkylphosphonates in 40-71% yields (Scheme 3.40). 2 a photochemical variant, which avoids heating the reaction mixture with a peroxide, was reported later. This milder method allows the preparation of functionalized perfluoroalkylphosphonates in good yields... 

A recent report describes the reaction of trifluoromethyl iodide with tetraethyl pyrophosphite under UV irradiation at room temperatme. The resulting diethyl trifluoromethylphosphonite is oxidized with t-BuOOH to give the corresponding phosphonate in 63% yield (see also Section 3.1.2.51.- ... 

Peptide synthesis /-Amyl chloroformate. Bis-(2,4-dinitrophenyl)carbonate. Bis-o-phenylene pyrophosphite. i-Butyl chloroformate. sec-Butyl chloroformate. /-Butyl chloroformate. /-Butyl 2,4,5-trichlorophenyl carbonate. CopoIy(ethylene-N-hydroxymaleimide). N,N-Diethyl-I-propynylamine. Di-(p-nitrophenyl)sulfate. Ethoxyacetylene. N-Ethoxycarbonyl-2-ethoxy-l,2-dihydroquinoline. N-Ethylbenzisoxazolium fluoroborate. Ethyl chloroformate. N-Ethyl-5-phenylisoxazolium-3 -sulfonate. N-Hydroxysuccinimide trifluoroacetate. Methyl-morpholine. 4-Methylthiophenol. p-Nitrophenol. Oxalylchloride. Pentachlorophenol. Pentamethylbenzyl chloride. /-Pentyl chloroformate. Phenacyl bromide. Polyhexamethylene carbodiimide. Tetraethyl pyrophosphite. 1,2,4-Triazole. 

Page 389, Sodium trithiocarbonate, add Supplier Eastman Page 397, Tetramethyl pyrophosphite, read Tetraethyl pyrophosphite Page 406, Thallium triacetate, add additional reference Review W. Kitching, Organometallic Chem. Rev.. 3,61 (1968)... 

A variation of this type of reaction involving interaction of tetraethyl pyrophosphite with an amino acid has been employed for peptide synthesis (12). In this instance, the initial product, an acyloxy phosphite (22), is sufficiently reactive to interact with an amino acid ester to yield a peptide and diethyl phosphonate. 

For the combination of segments according to this 3 + 4 = 7 2 + 7 = 9 scheme, the tetraethyl pyrophosphite method, which had just been developed, (G.W. Anderson et al.) [21] was applied. The blocked nonapeptide was secured in low... 

G. W. Anderson, J. Blodinger, A.D. Welcher, Tetraethyl pyrophosphite as reagent in peptide synthesis. J. Amer. Chem. Soc. 74 5309-5312 (1952)... 

EtO)gP,(PhO)gP (MeO)gP Mel-Pyrophosphites, Tetraethyl pyrophosphite, Bispyrocatechyl -PO/-H2PO2-HgP02... 

Tetraethyl pyrophosphite Pyrophosphoric acid esters with organic dehydrating agents... 

A soln. of diethyl hydrogen phosphate in dry benzene added with stirring to a soln. of tetraethyl pyrophosphite in the same solvent, kept 1.5 hrs. at 45°, and allowed to stand overnight at room temp. tetraethyl pyrophosphate (Y 97%) and diethyl phosphite (Y 87%). F. e. and dehydrating agents s. T. Mukaiyama, T. Hata, and O. Mitsunobu, J. Org. Ghem. 27, 1815 (1962). 

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