Phosphorus trichloride reaction with alcohols

Corey and J. E. Anderson154 have described a useful method for the conversion of alcohols into iodides by employing the reagent 120, which is readily prepared from catechol and phosphorus trichloride. Reaction of 120 in ether solution with an alcohol in the presence of pyridine affords the corresponding phosphite 121. Treat-... 

Platinum(II)15 and palladium(II)16 complexes of phosphorus trichloride undergo solvolysis in water and alcohols to form complexes with orthophosphorous acid or orthophosphite ligands (equation 6). Similar reactions occur between the palladium(II) phenyldichlorophosphine complex (8) and the diols ethyleneglycol and catechol, but new chelate rings are not formed (Scheme 2). Solvolysis also occurs with attack of diphenylphosphinic acid or a similar diphenylchlorophosphine complex (9) (equation 7). The palladium complexes (8) and (9) are unstable to excess methanol, water or base and undergo reduction. Similarly, the phosphorus trichloride gold(I) complex (10) is reduced by water, but forms stable products on reaction with alcohols (equation 8).15 During the above reactions, the phosphorus—metal bond remains intact and the overall process is one of substitution at phosphorus. 

Reaction with phosphorus trihalides (Section 4 13) Phosphorus trichloride and phosphorus tribromide convert alcohols to alkyl halides... 

On the other hand, phosphorous acid monoesters of lower alcohols easily undergo transesterification [75]. A preferred starting material is the triester of ethylene chlorohydrin, obtained by reaction of phosphorus trichloride with ethylene oxide, according to Eq. (28). 

Another general method for converting alcohols to halides involves reactions with halides of certain nonmetallic elements. Thionyl chloride, phosphorus trichloride, and phosphorus tribromide are the most common examples of this group of reagents. These reagents are suitable for alcohols that are neither acid sensitive nor prone to structural rearrangement. The reaction of alcohols with thionyl chloride initially results in the formation of a chlorosulfite ester. There are two mechanisms by which the chlorosulfite can be converted to a chloride. In aprotic nucleophilic solvents, such as dioxane, solvent participation can lead to overall retention of configuration.7... 

The title compound is formed by reaction of allyl alcohol with phosphorus trichloride and is reported to polymerise explosively if the material, when being purified by distillation, is taken down to less than half its bulk. 

A series of 2-chloro-l,3,2-oxazaphospholidine derivatives 131a-f were prepared by reaction of six enantio-pure alcohols 129a-f with phosphorus trichloride carried out in the presence of an organic base as HC1 scavenger (Scheme 38) [69], The 31P and II-NMR spectra of crude 131a, d, e containing a small amount of the HC1 salt produced during the synthesis of 131, as well as the distilled samples, indicated that the formed chloro derivatives were ca. 1 1 mixtures of the cis and trans isomers. 

The apparatus shown in Fig. 16 is set up in the fume hood. The equipment is flushed with dry nitrogen, then a 200-ml. portion (314.8 g., 2.29 mols) of phosphorus trichloride is placed in the 2-1. reaction flask. The flask is partially immersed in the Dry Ice-isopropyl alcohol bath the clamp to the alkylamine container is opened and a stream of dry nitrogen is passed through the system at a rate of about 30 cc./minute measured at S.T.P. The nitrogen stream sweeps the anhydrous amine (200 g.) from the bottle into the reactor. The amine usually condenses on one of the two cold fingers of the reactor and drips into the chilled stirred phosphorus trichloride solution. Finely divided dimethylammonium chloride precipitates immediately. 

Numerous preparative methods have been reported for these acids and their salts and ester derivatives.1 4 Dithiophosphoric acids are accessible from the reaction of phosphorus pentasulfide with alcohols or phenols (Equation 18). Dithiophosphinic acids can be prepared from thiophosphinic chlorides and sodium hydrosulfide (Equation 19), although the phenyl derivative is better prepared using a modified Friedel-Crafts reaction in which phosphorus pentasulfide is reacted with benzene in the presence of anhydrous aluminium trichloride (Equation 20). 

From phosphorus trichloride, benzyl alcohol and 2 mol. of a tertiary base, dibenzyl hydrogen phosphite (XIV), is obtained which on treatment with chlorine or a chlorinating agent (e.g. sulphuryl chloride)4 gives the phosphorochloridate (XV). Although not isolated, (XV) is almost certainly obtained by treatment of (XIV) with a polyhalogen hydrocarbon because reaction in the presence of an alcohol or of a primary or secondary amine gives a triester (XVI) or a phosphoramidate. 

The reaction of phosphorus tribromide with the alcohol above has been reported by Marvel to give the analogous bromide. The use of phosphorus trichloride did not yield the chloride [80]. 

Treatment of propargyl alcohols with phosphorus trichloride gives chloroallenes and these can undergo dimerization under the reaction conditions, as in the case of the formation of cyclobutanes 15 and 16.30... 

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