Alkyl dichlorophosphines

The iodo-phosphine (50) decomposes at temperatures above —50 °C to give the phosphorane (51).42 Phosphorus trichloride is oxidized by the sulphenyl chloride (52).48 Aryl- and alkyl-dichlorophosphines have been converted into the phosphor-... 

The same authors also reported the preparation of 1,2-oxaphosphole derivatives from the reaction of alkyl(phenyl)dichlorophosphines with unsaturated ketones (Scheme 4) [33],... 

Benzannulated NHPs are straightforwardly accessible from AUV-disubsti luted o-phenylenediamines either via base-induced condensation with substituted dichlorophosphines [25] or PC13 [26], or via transamination with tris(dialkylamino) phosphines [13, 14, 27], respectively. An analogous NH-substituted derivative was obtained in low yield via transamination of o-phcnylcncdiaminc with ethoxy-bis(diethylamino)phosphine [28], and condensation of o-phenylenediamine with excess tris(diethylamino)phosphine furnished a l,3-bis(phosphino)-substituted heterocycle [29], Intermediates with one or two NH functions were detectable by spectroscopy but could not be isolated in pure form under these conditions. However, 2-chloro-benzo-l,3,2-diazaphospholene and the corresponding 1-phenyl derivative were prepared in acceptable yield via condensation of PC13 with o-phenylenediamine under microwave irradiation [30], or with A-phenyl-o-phenylenediamine under reflux [27], respectively, in the absence of additional base. The formation of tetrameric benzo-NHPs during transamination of A-alkyl-o-phenylenediamines with P(NMe2)3 has already been mentioned (cf. the section entitled 1,3,2-Diazaphospholes and 1,3,2-Diazaphospholides ). 

Diazadiphospholes (182) (R = Me, Ph) are obtained from the condensation of methylene bis(dichlorophosphine) and a hydrazine (Scheme 56) <85AG127>. l-Phenyl-l,2,3,5-diazadiphosphole is a colorless, air-sensitive liquid. It is not alkylated by methyl iodide or trimethyloxonium tetra-... 

The dialkyl and trialkyl compounds can also be obtained by using different ratios of the alkylating agent to PC13. At high temperatures (600-700 °C), PC13 reacts with benzene to produce phenyl dichlorophosphine ... 

Nucleophilic substitutions involving phospholide anions and main-group electrophiles have also been investigated. For example, 1-phosphinophospholes have been prepared in good yields by nucleophilic attack of 3,4-dimethylphos-pholide anion on alkyl and aryl dichlorophosphines <1997JOM197>. This approach has also been used to prepare the diphosphine 30, which has a highly polarized P-P bond <2004AGE4801>. 

The reaction of white phosphorus with alkyl or aryl halides using PX3 as solvent has recently been used to prepare p- ClCgl PClj (34%) phenylene-bis (dichlorophosphine) (J) (38%),... 

In 1959 Kulakova et al. (183) reported the successful isolation of several rather unstable alkyl- and aryldifluorophosphines RPF2 (R = Me, Et, Ph, n-Bu) by reacting the corresponding dichlorophosphines RPCI2 with antimony trifluoride in an inert solvent under mild conditions. The resulting difluorophosphines are inflammable liquids or gases which... 

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