Phosphonic chlorides

An interesting comparison has been made between the behaviour of (78)—(80) in their reaction with Cl2 and SOaCla.61 Compounds (78) and (79) react at -70 °C via phosphonium-like intermediates, with retention of configuration in the former case the product is the phosphonic chloride (81) whereas (79) yields the cyclic oxophos-phoranesulphenyl chloride (82). On the other hand, the benzodioxaphospholan (80)... 

In reactions between the cyclic phosphonic chloride (137) and the diols (138), the composition of the reaction products that have not been thermally treated differ widely, depending on , the compound (139) that is initially formed evidently undergoing further change. When n=2, the product then consists of either (140) or (141)... 

Thus, in the year 1950, an inventor named Tolkmith (IS) presented a patent application claiming a certain methane phosphonic chloride. The only utility stated for the compound was that it was of value as an intermediate for the preparation of more complex phosphorus derivatives and as a constituent of a parasiticide. The Patent Office Board of Appeals in its decision, held that the applicant s showing of utility did not comply with Section 112 of the patent statutes requiring that the manner and process of making and using the invention be described in such exact terms as to enable one skilled in the art to make and use the same. The board went on to say ... 

In other developments, Lecat and Devaud ° have proposed an electrochemical reduction (Scheme 4) to recover triphenylphosphine from triphenylphosphine oxide produced, for example, in the Wittig reaction. Yields of up to 86% were obtained. Engel and Chakrabarty have reduced phosphoric and phosphonic chlorides to the corresponding monobasic phosphorous and phosphonous acid derivatives (equations 23 and 24), using NaBH4 in refluxing dioxane. Triphenylphosphine oxide is reportedly reduced to triphenylphosphine in 75% yield by the electron-transfer system Smh-THF-HMPA, at 65 °C. 

Removal of the ester Et group with Me SiBr, followed by treatment of the product (112 d) with oxalyl chloride led to the cyclic phosphonic chloride (112 e) as stereoisomeric mixture further reaction with PhSH under basic conditions gave (112 f), also as a mixture of stereoisomers. The (2 ) form of (112 f) reacted with vinylmagnesium bromide to give the 2-vinyl derivative, a step which failed, however, with the (2B) epimer. Attempts to oxidatively cleave the vinyl group and so generate a compound having a carbonyl... 

CCl -Et N in the presence of a nucleophile R YH can be so regulated that the intermediate phosphonic chloride does not... 

Phosphorus pentachloride adds exothermally to numerous 1-alkenes, giving products that usually afford alkenyltrichlorophosphonium hexachlorophos-phates by loss of HC1. These extremely hygroscopic products can be converted into phosphonic chlorides by phosphorus(v) oxide or, better, by sulfur dioxide. 

Phosphonic chlorides can be prepared analogously from dichlorophosphines, and phosphine oxides from monochlorophosphines.106... 

Isomerization is observed with higher alkyl halides, as in Friedel-Crafts reactions isopropylphosphonic dichloride is stated to be the sole product from n-propyl chloride,190,191 and terf-pentyl chloride undergoes C-C fission, yielding the tert-butyl acid.193 On reduction by lithium tetrahydroaluminate the phosphonic chloride formed from w-butyl chloride gives a primary phosphine that is shown by 31P-nuclear magnetic resonance to consist of n- and sec-butylphosphine in the proportions 5 95 and the product from n-octyl chloride was similarly shown to contain all four position isomers.194... 

Dithiophosphinic acids are produced in good yield by the reaction of the perthiophosphinic anhydride (81) with Grignard reagents. Reaction of H2S with compounds containing a P—Cl bond can, in selected cases, provide a convenient route to phosphonothioates. Thus the adduct of acetal and phosphorus pentachloride gives (82) under these conditions, and the cyclic trimeric anhydride (83) is formed from the phosphonic chloride (84). ... 

The action of PCI5 on (2-chloroalkyl)phosphonic dichlorides yields complexes, probably of the composition 92 which, when heated at only moderate temperature, afford the tetrachloroalkanes 93 Even the reaction between PCI5 and bis(hydroxymethyl)phos-phinic acid, and that between the products therefrom and more PCI5 represent a complex picture which involves the fission of phosphorus-carbon bonds in several compounds the reactions are represented, in overall terms, by equation 3 (the yields of the phosphinic and phosphonic chlorides were ca 50% and ca 30% at 0-10 °C, although the former increases at the expense of the latter at 50 and equations 4 and 5 (reactions at about 100... 

Calcium or magnesium salts catalyse reactions between perfluoroalkanols and phos-phinic chlorides or phosphonic chlorides Reactions between MeP(0)Cl2 and chiral alcohols and chiral thiols " have been employed in the determination of the stereochemical composition of the alcohol or thiol by an NMR method. Phosphonic monoesters have been esterified by secondary alcohols in the presence of BOP-type reagents, e.g. 532 (R =. After the selective monodemethylation of a dimethyl ester by means of a metal... 

This reaction provides a convenient method for preparing alkyl phosphonic chloride, which is an important intermediate for alkyl phosphonic acid and corresponding esters. 

Phosphonous esters are produced by the action of alcohols on phosphonous diamides (7.184), phosphonamidous esters (6.218) or phosphonous dichlorides in the presence of a base such as trieth-ylamine or pyridine which ranoves hydrogen chloride (6.219). In the absence of bases the dichloride gives phosphinic esters (Fignre 6.4). Alkoxides in dry ether react smoothly with phosphonous chlorides (6.220). 

Some 4-coordinated cyclodiphosphazanes (phosphetidines) can be synthesised from amines and phosphonic chlorides (7.249) or trialkylamino phosphine oxides (7.250), or in some cases from cyclodiphosphazanes of types (7.244a,c), (7.251) and (7.252). 

We also note here the synthesis of (70) and (71) by condensation of a tetrahydrothiapyran-4-one or a piperidone with benzaldehyde and ammonium acetate, of the sulphonamide (72), and of the products of reaction of phosphonous chlorides with the diamines (73)—(75). The synthesis and X-ray structural analysis of (76) are reported. ... 

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