Phosphoranes Fluorophosphoranes

This initial hypothesis was subsequently refined by the deduction of two preference rules for the structures of the intermediate pentacovalent phosphorus derivatives, the phosphoranes. Muetterties and Schunn65. in order to rationalize the nmr spectra of a number of alkyl fluorophosphoranes (CH3) -PF5 . formulated the hypothesis that the more electronegative fluorine atoms... 

The high stability of fluorophosphoranes gives rise to addition products of the phosphorane series. Some examples are recorded in Scheme 21 (72CC272, 74MI11701, 64SA1835, 65MI11701, 70RCR1). 

The different Vfp coupling constants to apical and equatorial CFg groups allow the stable conformations at low temperatures of a variety of trifluoro-methylphosphoranes to be established. This leads to the partial apicophilicity series F, Cl > CF3 > OSiMes, OMe, SMe, NH2, H, Me. The phosphoranes (CFa)3pH2, CF3PF3H, and (CF3)aPFaH have been prepared by reduction of the corresponding fluorophosphoranes with trimethylsilane in the vapour phase. The stable conformations at low temperatures of the first two are (3) and (4)... 

The bis(trimethylsilyl) ether (36) with fluorophosphoranes gave the monocyclic phosphoranes (37), except with tetrafluorophosphoranes and... 

A phenylpentafluorophosphate, together with a novel cationic species, also resulted from the isomerization of phenyldimethylaminotrifluoro-phosphorane. It occurs when the fluorophosphorane is allowed to stand at room temperature. 

Halogenotrifluoromethyl-phosphines and -phosphoranes. The synthesis and stereochemistry of fluorophosphoranes RaPFj,-a (R = alkyl or aryl x — 1,2, or 3) have been extensively discussed, but comparatively little information is available on mixed halogenofluorophosphoranes of general formula... 

---