Chloro phosphines, reactions

In the course of a study of the formation of fluorophosphoranes from chloro-phosphines (22) we observed one exception in the compound chloromethyldi-chlorophosphine, which reacted smoothly with antimony trifluoride to give the flammable fluorophosphine, C1CH2PF2, under conditions where many other chloro-phosphines were invariably converted into fluorophosphoranes. As this fluorophosphine is readily available, its interaction with a metal carbonyl derivative was studied, and cycloheptatriene molybdenum tricarbonyl, obtained from the reaction of molybdenum hexacarbonyl with cycloheptatriene (I, 2), was chosen as a starting compound. 

Fluorophosphinenickel(O) complexes can be formed by reaction of the corresponding chloro-phosphine complexes with potassium fluorosulfinate (equations 9 and 10).1718 The metal inhibits oxidation of the ligand to the phosphinic fluoride, a reaction that occurs readily to the free ligand. 

Phosphines and phosphides react rapidly with positive halogen and hence polyhalogen compounds, e.g. tetrachloromethane, are particularly suitable and have the advantage that the chloro-phosphine formed is rapidly attacked by the nucleophile. In principle therefore the phosphorus atoms can be fully substituted by reactions of the following type,... 

Preparations and reactions of some mono(trialkylsilyl)phosphines, which derived from bis(trialkylsilyl)phosphines, were described in Sections II.A and II.B. Other preparative methods of mono(trialkylsilyl)phosphines are described in Reference 10. Reactions of some mono(trialkylsilyl)phosphines with hexachloroethane or phosgene lead to chloro-phosphines (equation 42)66. It should be noted that treatment of bis(trialky lsilyl)phosphines... 

The reaction is conducted in a 250-mL, three-necked flask, fitted with a mechanical stirrer, a thermometer reaching close to the bottom of the flask, and a 25-cm Vigreux column to which has been connected a distillation head with multiple receiver. tert-Butyldichlorophosphine (31.8 g, 0.2 mole) is added to a stirred suspension of NaF (25.2 g, 0.6 mole) in 100 mL of sulfolane over a period of 1 hour. A slow stream of nitrogen is passed through a T-tube connected to the outlet of the distillation apparatus. After the addition of the chloro-phosphine, the reaction mixture is heated as follows 45 minutes at 80°, 15 minutes at 100-180°, and 30 minutes at 180°. Distillation of the fluorophosphine commences at 80° and is complete at 180°. The product is collected in a receiver flask cooled in Dry Ice. fer -Butyldifluorophosphine is obtained as a colorless liquid of bp 41-44° the yield is 20-23 g (79-91%, based on tert-butyl-dichlorophosphine ). Anal. Calcd. for C4H9F2P P, 24.6 F, 30.2. Found P, 24.1 F, 29.0,... 

The reaction of trichlorogermylphosphines (226) with DBU gave chloro-phosphine 227 and a DBU -germanium dichloride complex (228) (84CC1621). 

The cleavage of the Si—N bond in iV-silylphosphazenes generally provides a versatile means of changing the iV-substituents. However, reactions with chloro-phosphines are more complex in that a rapid quatemization step may occur, e.g. 

Preparation. - Fluorophosphines have been obtained from the reactions of the related chlorophosphines with trimethyl tin fluoride. Phenyl(isopropyl)-fluorophosphine has been resolved via a chiral amine-palladium(II) complex, providing the first example of the resolution of a free fluorophosphine chiral at phosphorus. This compound racemises at 20 °C in benzene solution over six hours. The neat compound rapidly decomposes by redox disproportionation. The same approach has been used for the resolution of the related chloro-phosphine, but the optically active compound could not be liberated unchanged from the crystallised diastereoisomeric palladium complex. The dihalo-genophosphines... 

The d trihydrides CP2MH3 (M = Nb, Ta) also give fast reactions with chloro-phosphines leading to symmetrical ionic compounds. The central position of the PR2H group has been unambiguously established by H NMR spectroscopy. ... 

Hindered rotation about the P—C bond is indicated in a recent electron-diffraction study of phenyldichlorophosphine. The reaction of the chloro-phosphines RPClg and RgPCl with trifluoroacetic acid gives the unstable acetoxy-derivatives R,P(OCOCFg)3 , = 1 or 2, R = Et or Ph. On heating, the monoethyl compound loses trifluoroacetic anhydride and carbon monoxide, i.e. 

During the past several years the use of secondary phosphine oxides, chloro-phosphines, and related species as ligands for late-transition metal catalysts has been explored by several groups (reviews [81, 82]). Catalysts supported by these unusual ligands have shown some utihty in Pd-catalyzed A-arylation reactions. For example, treatment of 4-chlorobenzotrifluoride with piperidine and NaOfBu in the presence... 

Formic acid behaves differently. The expected octadienyl formate is not formed. The reaction of butadiene carried out in formic acid and triethylamine affords 1,7-octadiene (41) as the major product and 1,6-octadiene as a minor product[41-43], Formic acid is a hydride source. It is known that the Pd hydride formed from palladium formate attacks the substituted side of tt-allylpalladium to form the terminal alkene[44] (see Section 2.8). The reductive dimerization of isoprene in formic acid in the presence of Et3N using tri(i)-tolyl)phosphine at room temperature afforded a mixture of dimers in 87% yield, which contained 71% of the head-to-tail dimers 42a and 42b. The mixture was treated with concentrated HCl to give an easily separable chloro derivative 43. By this means, a- and d-citronellol (44 and 45) were pre-pared[45]. 

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