catena‐Phosphorus Cations

Abstract

Recent advances towards a systematic development of catena-phosphorus cations are reviewed. The cations represented in this new and developing chapter in fundamental phosphorus chemistry complement the series of neutral and anionic polyphosphorus compounds.

Phosphacycles as Building Blocks for Main Group Cages

“…For example, Krossing and co-workers reported [3] that PX 3 (X = Br, I) reacts in CH 2 Cl 2 at À78 8C with Ag[Al(OR F ) 4 ] (R F = C(CF 3 ) 3 ) and P 4 to give the novel phosphorus rich molecules [P 5 X 2 ][Al(OR F ) 4 ] through a process thought to involve the insertion of the electrophilic carbenoid species [PX 2 ][Al-(OR F ) 4 ] into a PÀP bond of P 4 . Allied to this interesting observation is the report by Weigand and co-workers [4] that P 4 reacts, possibly by a similar reaction pathway, in a melt of Ph 2 PCl and GaCl 3 (1:1 at 60 8C) to form a structurally related molecule [P 5 Ph 2 ] [GaCl 4 ]. Similarly, Burford and co-workers have used related methodology to prepare an extensive series of catena-phosphorus cations.…”

“…Similarly, Burford and co-workers have used related methodology to prepare an extensive series of catena-phosphorus cations. [5] In our initial studies we focused on the reaction of 2,4,6tri-tert-butyl-1,3,5-triphosphabenzene (1) with latent sources of PX 2 + and AsX 2 + cations. It is interesting to note that 1 reacts with the Arduengo-type carbene 1,3,4,5-tetramethylimidazol-2-ylidene to give a ring-contracted 1,2,4-triphosphole, [6] whereas the silicon analogues, stable bis-(amine)silylenes, afford (4+1) cycloaddition products.…”

Isodiagonality in the periodic table

“…For example, research published in 2000 describes the phospha-Wittig reaction (Shah and Protasiewicz 2000). Subsequently, isodiagonality was cited in the context of phosphorus-containing heterocycles (Modelli et al 2004) and in a review of poly-phospho-cation species (Dyker and Burford, 2008).…”

Hochgeladene P1‐zentrierte Kationen: Aussichten in der Synthese

“…[3] Bekannte, auf phosphorhaltigen Reagentien beruhende Reaktionen wie die Wittig-, Mitsunobu-, Corey-Fuchs-und Michaelis-Arbuzov-Reaktion verlaufen über monokationische Zwischenstufen. Allerdings konnte in den letzten Jahren eine Vielzahl von P-zentrierten Kationen mit unterschiedlichsten Bindungsmotiven am Phosphoratom zugänglich gemacht werden.…”