Benzyl diethyl phosphite

Evidence strongly supporting this latter mechanism was obtained by Cadogan and Foster, who subjected jSjS-dimethylphenylethyl diethyl phosphite and benzyl diethyl phosphite to peroxide-catalyzed reaction with carbon tetrachloride. These workers showed by careful gas chromatography the absence of any products expected from the rearrangement, dimerization or disproportionation of free /3j(3-dimethyl-phenylethyl (PhCMe2CH2 ) or benzyl radicals. 

Benzylphosphonic acid esters. A soln. of benzyl diethyl phosphite (0.1-0.2 M) in deoxygenated benzene irradiated in a quartz tube with a 450 W medium-pressure Hg-lamp - diethyl benzylphosphonate. Y 85-95%. With chiral O-benzyl groups, reaction proceeds with complete retention of configuration at the chiral carbon, F.e.s. W.G. Bentrude et al., J. Am. Chem. Soc. 110, 6908-9 (1988) stereochemistry s.a. Tetrahedron Letters 30, 1025-8 (1989). 

Stable HHTs such as the A -benzyl derivative 22, when reacted with neat diethyl phosphite under fairly forcing conditions, gave the desired a-aminomethylphosphonate... 

Tanaka, H, Sakamoto, H, Sano, A, Nakamura, S, Nakajima, M, Hashimoto, S, An extremely mild and stereocontrolled construction of 1,2-cri-a-glycosidic hnkages via benzyl-protected glycopyranosyl diethyl phosphites, Chem. Common., 1259-1260, 1999. 

The diethyl 5-(benzyloxycarbonyl)pentylphosphonate has been prepared from sodium diethyl phosphite and benzyl 6-bromohexanoate in DMF at room temperature. " Similarly, dimethyl... 

The addition of lithium diethyl phosphite to the imines (201) from (/ )-(—)- -amino-l-phenyl-2-methoxyethane gave mixtures of (202) and (203) in the ratios of >110 1 to 7 1, but mostly around 50 1. The sequence was completed by hydrogenolytic removal of the benzylic group, when the product (1-aminoalkyl)-phosphonic diesters had e.e.s of 96-99%. The diastereoisomeric ratios within (205), obtained from the chiral sulfoxides (204) and diethyl (lithiomethyl)phos-phonate, varied from 4.9 1 (R = PhCH=CH) to 9.2 1 (R = 2-thienyl), but the ratio also depended, to some extent, on the nature of the phosphonate alkyl group. ... 

S. An extremely mild and stereocontrolled construction of 1,2-cis-a-glycosidic linkages via benzyl-protected glycopyranosyl diethyl phosphites. Chem Com-... 

Preparation of diethyl 3,5-di-t-butyl-4-hydroxybenzylphosphonate — Reaction of a benzylic acetate with a trialkyl phosphite... 

When the halogen compound employed in the first step has an activated halogen atom (RCH CHCHjX, QHjCHjX, XCH2CO2H) a simpler procedure known as the Horner phosphonate modification of the Wittig reaction is applicable. When benzyl chloride is heated with triethyl phosphite, ethyl chloride is eliminated from the initially formed phosphonium chloride with the production of diethyl benzylphosphonate. This phospho-... 

Preparation of phosphonates for modeled Wittig reaction. In a typical synthesis benzyl chloride is added to triethyl phosphite to form benzyltriethylphosphonium chloride, which on brief refluxing loses ethyl chloride to form diethyl benzylphos-... 

Diethyl [(benzyloxycarbonyl)methyl]phosphonate 268 A mixture of benzyl chloroacetate (18.5 g, 0.1 mole) and triethyl phosphite (18.3 g, 0.11 mole) is heated at 175° the internal temperature then rises somewhat and ethyl chloride distils off. When the exothermal reaction ceases, the mixture is heated for 1 h at 200° and then distilled in a vacuum this affords 87% (25.1 g) of a product, b.p. 148-169°/l mm. Redistillation gives analytically pure material having b.p. 174-179°/1.5 mm, nD24 1.4932. 

Many communications have concentrated on specific amino phosphonic acids or derivative types. Thus, esters of phosphonoaminoacetic add were obtained by the reactions between trialkyl (ethyl) phosphite and (218) and which are thought to proceed via the phosphorane (219). A sequence has been presented for the preparation of the mono- and di-benzyl esters of N-chz protected (a-aminoben-zyl)phosphonic acid. A synthesis of (aminomethylene)bisphosphonic acid from dibenzylamine, dibenzyl hydrogenphosphonate and triethyl orthoformate has been noted and the asymmetric hydrogenation of (220) in the presence of chiral phosphine catalysts yields samples of (221) with e.e.s of 63-96%. The pyrrolidine-based compound (222) has been prepared from methyl S)-N-methoxycarbonyl-4-oxo-2-pyrrolidinecarboxylate and iV-coupled 4-amino-butanal diethyl acetals were the starting materials in syntheses of the pyrrolidine-2-phosphonic add derivatives (223) in which Z represents the iV-protected amino add or peptide moiety. ... 

A one-pot process has been devised for the synthesis of dialkyl [(a-phenylamino)ben-zyljphosphonates from dialkyl hydrogenphosphonate, benzaldehyde and aniline, presumably adaptable for other aromatic amines or aldehydes To avoid multiple reactions of the Mannich type when using a primary amine and a particularly reactive carbonyl component such as formaldehyde, initial silylation of the amine, or the use of diethyl trimethylsilyl phosphite, are valuable moderating variations The amine can be replaced by a carboxamide" or carbamate ester, conveniently the benzyl ester , and the product can then be selectively deacylated with HBr in acetic acid at room temperature or by hydrogenolysis. Alternatively, even a phosphoric amide may be used to afford an A-phos-phorylated product (221)" ... 

Referring to the reported literatures [55, 56, 73], we attempted to prepare (S)-enantiomers of l-hydroxy(substituted phenyl)methylphosphonates M2 including M2-6, M2-7, M2-9, and M2-13 by enantioselective hydroxylation. In this way, substituted benzyl chlorides and triethyl phosphite as starting materials via Arbuzov reaction[74] formed 0,0-diethyl (substituted benzyl)phosphonates M23, which... 

Several (9,(9-diethyl (substituted benzyl)phosphonates M23 as important intermediates were readily prepared from substituted benzyl chlorides and triethyl phosphite via Arbuzov reaction (Table 6.5) [74]. 

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