Synthesis of the Phospha‐Wittig Reagent Me ₃ P = P(C ₂ F ₅ ) and Generation of a Phospanyl‐Wittig Derivative Me ₃ P = C(CF ₃ )P(C ₂ F ₅ )F

In this contribution, we report the synthesis of the diphosphane P 2 (C 2 F 5 ) 4 and cyclotetraphosphane (PC 2 F 5 ) 4 from the corresponding bromophosphanes P(C 2 F 5 ) x Br 3− x ( x = 1, 2). The molecular structure of the cyclotetraphosphane was determined by x‐ray diffraction analysis. Subsequent reaction of P 2 (C 2 F 5 ) 4 with trimethylphosphane (PMe 3 ) afforded the phosphanyl‐functionalized phosphorus ylide (Wittig reagent) Me 3 P = C(CF 3 )P(C 2 F 5 )F, whereas treatment of (PC 2 F 5 ) 4 with PMe 3 yielded the base‐stabilized phosphinidene Me 3 P = P(C 2 F 5 ). The newly obtained species were characterized by multinuclear NMR spectroscopy, and the molecular structures were determined by x‐ray diffraction analysis. Me 3 P = C(CF 3 )P(C 2 F 5 )F as well as Me 3 P = P(C 2 F 5 ) represent unique structural motifs that have not been observed within their respective substance class, underlining the remarkable versatility of perfluoroalkyl substituents.