Triphenylphosphine Carbon tetrachloride

Physical Data PhsP mp 79-81 °C bp 377 °C d 1.0749gcm- CCU mp -23 °C bp 77 °C d 1.594gcm-l Solubility sol CCU, MeCN, CH2CI2, 1,2-dichloroethane. Preparative Method reactive intermediates are generated in situ by reaction of Ph3P and CCU- 

Handling, Storage, and Precautions Ph3P is an irritant CCU is toxic and a cancer suspect agent use in a fume hood. Solvents must be carefully dried because the intermediates are all susceptible to hydrolysis. 

Conversion of Aicohols to Alkyl Chlorides. The reaction of alcohols with Triphenylphosphine and carbon tetrachloride results in the formation of alkyl chlorides. The mild, neutral conditions allow for the efficient conversion of even sensitive alcohols into the corresponding chlorides (eqs 1 and 2). The reaction typically proceeds with inversion of configuration. In eq 3, it is interesting to note that the reaction not only proceeds with inversion of configuration but also no acyloxy migration is observed.  

The conversion of an allylic alcohol to an allylic chloride occurs with no or minimal allylic rearrangement (eqs 4 and 5). For the synthesis of low boiling allylic alcohols, it is advantageous to substitute hexachloroacetone (HCA) for CCU (eq 6). The stereo- 

If the conversion of the alcohol to the chloride is attempted in refluxing MeCN, dehydration to form the alkene occurs (eqs 7 and 8). Occasionally the separation of the product from the triphenylphosphine oxide produced in the reaction can be problematic. This can be overcome by using a polymer-supported phosphine. Simple filtration and evaporation of the solvent are all that is required under these conditions. Not only is the workup facilitated, but the rate of the reaction is also increased by employing the supported reagent.  

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The use of the triphenylphosphine-carbon tetrachloride adduct for dehydration reactions appears to be a very simple way of synthesizing nitriles from amides, carbodi-imides from ureas, and isocyanides from monosubstituted formamides. All of these reactions involve the simultaneous addition of triphenylphosphine, carbon tetrachloride, and tri-ethylamine to the compound to be dehydrated. The elimination of the elements of water is stepwise. An adduct, e.g. (46), is first formed, chloroform being eliminated, which decomposes to produce hydrogen chloride and the dehydrated product. 

Benzotriazole-related methodology publications appeared in 2006. Reaction of 1-formylbenzotriazole with triphenylphosphine/carbon tetrachloride afforded l-(2,2-dichlorovinyl)benzotriazole, where lithiation followed addition of electrophiles gave a variety of functionalized M-(ethynyl)benzotriazoles <06T3794>. Novel mono- and symmetrical di-/V-hydroxy- and IV-aminoguanidines were readily prepared from the reaction of diverse hydroxylamines or hydrazines with reagent classes di(benzotriazol-l-yl)methanimine, (bis-benzotriazol-1 -y 1-methy lene)amines, benzotriazole-1 -carboxamidines, benzotriazole-1 -... 

The /V -hydroxylamino compounds (404) and (405), obtained from the reaction of tert-butyl acetate with 3,4-dihydroisoquinoline-A-oxide or 5,5-dimethyl-pyrroline-/V-oxide, when boiled in methylene chloride in the presence of triphenylphosphine, carbon tetrachloride and triethylamine, are transformed to (1,2,3,4- tetrahydroisoquinolin-l-ilidene) acetate (406) or (pyrrolidin-2-ilidene) acetate (407) (Scheme 2.181) (645). 

Two routes for the reaction of substrate with the triphenylphosphine-carbon tetrachloride reagent are now recognized.61 62>64 Direct interaction (76) of the substrate with the initially formed dipolar associate leads to the formation of chloroform and the intermediate phosphonium salt (77). 

The third paper in this group106 is concerned with the isolated triphenylphosphine-carbon tetrachloride system, and the authors show how these compounds react only in the presence of small amounts of polar impurities, to produce initially the salt... 

Ketenimines (144), generated from a-substituted benzophenone 1-acetamidoethyl-idenehydrazones with a mixture of triphenylphosphine, carbon tetrachloride and triethylamine in dichloromethane (Appel s conditions), have been used to synthesize a variety of 1,2,4-triazole-fiised heterocycles (see Scheme 56). Mechanistically, the... 

The use of triphenylphosphine-carbon tetrachloride to convert lincomycin (1) into clindamycin (2) has already been mentioned (see Section I, p. 226) the 7-bromo and 7-iodo analogs of 2 were also prepared by treatment of lincomycin hydrochloride with triphenylphosphine and carbon tetrabromide or carbon tetraiodide, with acetonitrile as the solvent.3... 

Chlorodeoxy sugars have been reduced [15] also with lithium aluminum hydride. In one experiment, 3-deuterio-l,2 5,6-di-0-isopropylidene-a-D-allofuranose was converted into 3-chloro-3-deoxy-3-deuterio-l,2 5,6-di-0-isopropylidene-a-D-glucofuranose by treatment with triphenylphosphine-carbon tetrachloride reduction with lithium aluminum hydride gave 3-deoxy-3-deuterio-1,2 5,6-di-0-isopropylidene-a-D-ro-hexofuranose with retention of configuration at C-3. 

CYCLODEHYDRATION Trifluoromethanesul-fonic acid. Triphenylphosphine-Carbon tetrachloride. 

Allylie chlorides. Allylic alcohols can be converted into allylic chlorides with no, or slight, rearrangement by the triphenylphosphine-carbon tetrachloride reagent/... 

ALLYLIC CHLORIDES N-Chlorosuc-cinimide-Dimethyl sulfide. Mcthanesul-fonyl chloride. Triphenylphosphine- Carbon tetrachloride. 

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